RATIONAL USE OF ANTIBIOTICS


EXPERT COMMITTEE ON RATIONAL USE OF ANTIBIOTICS

Chairman: V K E Lim
Members: O P Foo, R Jalleh, P Kandasami, E L Lee, J Mohan, T S Ng, S Rahman, T Essau


Contents

  1. GENERAL PRINCIPLES IN THE USE OF ANTIBIOTIC
    Introduction
    Monitoring efficacy

  2. ANTIBIOTICS GUIDELINES 1996
    2.1 Guidelines on antibiotic therapy

Table 1.    Respiratory Infections
Table 2.    Urinary Tract Infections
Table 3.    Skin and Soft Tissue Infections
Table 4.    Musculosketel Infections
Table 5.    Gastrointestinal Infections
Table 6.    Genitourinary Infections (Including Sexually Transmitted Diseases)
Table 7.    Central Nervous System Infections
Table 8.    Cardiovascular Infections
Table 9.    Bacteraemia And Septicaemia
Table 10.  Other Infections
Table 11.  Infections Associated With Pregnancy
Table 12.  Chemoprophylaxis For Selected Medical Condition

  1. SURGICAL CHEMOPROPHYLAXIS

  2. GUIDELINES FOR SURGICAL ANTIBIOTIC PROPHYLAXIS

  1. ANTIBIOTIC DOSAGES FOR ADULTS

  2. ANTIBIOTIC DOSAGES FOR NEONATES WITH SERIOUS INFECTIONS

  3. ANTIBIOTIC DOSAGES OF ORAL ANTIBIOTICS FOR NEONATES

  4. PARENTERAL ANTIBIOTIC DOSAGES FOR SERIOUS INFECTIONS IN INFANTS AND CHILDREN

  5. ANTIBIOTIC DOSAGES OF ORAL ANTIBIOTICS FOR INFANTS AND CHILDREN

  6. References


GENERAL PRINCIPLES IN THE USE OF ANTIBIOTICS

Introduction

Antibiotics are one of the most commonly prescribed drugs today. Rational use of antibiotics is extremely important as injudicious use can adversely affect the patient, cause emergence of antibiotic resistance and increase the cost of health care. Prescribing an antibiotic comprises several phases:

i) perception of need - is an antibiotic necessary ?
ii) choice of antibiotic - what is the most appropriate antibiotic ?
iii) choice of regimen : what dose, route, frequency and duration are needed ?
iv) monitoring efficacy : is the treatment effective ?

Is an antibiotic necessary?

Antibiotics are generally only useful for the treatment of bacterial infections. It is important to remember that not all fevers are due to infections and not all infections are caused by bacteria. The majority of infections seen in general practice are of viral origin and antibiotics can neither treat viral infections nor prevent secondary bacterial infections in these patients. Even where a bacterial aetiology is established, an antibiotic may not be always necessary. Many bacterial infections resolve spontaneously. Minor superficial skin infections may be more suitably treated with a local antiseptic. Collections of pus should be drained surgically and if drainage is adequate, antibiotics are often not required.
 
Choice of an antibiotic
The successful outcome of therapy would depend very much on the choice of the antibacterial agent. In the process of selecting an antibiotic, three main factors need to be considered; the aetiological agent, the patient and the antibiotic.
 
The aetiological agent
Determination of the aetiological agent depends on a combination of clinical acumen and laboratory support. In many instances an antibiotic prescription has to be made based on the clinical diagnosis (empirical therapy). Even where a bacteriology report is available it is necessary to interpret the report. Bacterial isolates from culture specimens may represent normal flora, colonisers or contaminants rather than true pathogens. Sensitivity results when available are at best only a guide to treatment. Laboratory reports should always be viewed in the light of clinical findings.
 
The patient
Several patient factors have to be considered in selecting an antibiotic. Age is an important factor. The very young and the very old tend to be more prone to the adverse effects of the antibiotics. Neonates have immature liver and renal functions which affect their ability to metabolise or excrete antibiotics. Antibiotics and their metabolites may adversely affect growing tissues and organs in children. Elderly patients are more likely to suffer from nephrotoxicity and allergic reactions. Dosage modifications would also have to be made in those patients with hepatic or renal impairment. Antibiotics can also give rise to severe toxic reactions in patients with certain genetic abnormalities eg sulphonamides in patients with glucose-6-phosphate dehydrogenase deficiency. Antibiotics should as far as possible be avoided in pregnancy and when it is necessary to use an antibiotic, betalactam antibiotics and erythromycin are probably the safest. A history of allergy to antibiotics should always be sought before administration. Routine intradermal test doses for penicillin allergy is of little value and may even be dangerous. If in doubt avoid betalactams and use a macrolide or tetracycline (in adults) instead. In serious infections like meningitis and bacteraemic shock the immediate institution of the best available antibiotic for the suspected pathogen(s) is imperative as delay in treatment will increase both mortality and morbidity. In less serious situations such as otitis media where spontaneous recovery is common, an antibiotic that covers for the predominant organisms is adequate.
 
The antibiotic
The clinician should have adequate knowledge of the pharmacokinetic properties of the antibiotic he uses. Antibiotics vary in their ability to be absorbed orally or to cross the blood brain barrier and these factors will affect their routes of administration. The ability of the antibiotic to achieve therapeutic concentrations at the site of infection is another important consideration thus antibiotics used for treating urinary infections should ideally be concentrated in urine. Some antibiotics have very severe toxic effects and are best avoided in certain conditions. The doctor should also be aware of drug-drug interactions since many antibiotics can interact with other non-antibiotic drugs. Finally the cost of the antibiotic is also of major concern. In calculating costs it is perhaps more reasonable to take into account the total cost of treatment rather than just the actual cost of antibiotic per dose. The route of administration, the necessity for monitoring antibiotic levels and the patient's length of stay in hospital can affect the cost of treatment as well. The patient's compliance to medication is an important factor for consideration in the choice of antibiotics.
 
Choice of regimen
Parenteral or oral
Whether the route of administration should be oral or parenteral would depend on whether the patient is able to take oral treatment reliably. In cases of severe sepsis where rigors, hyperthermia/hypothermia, tachycardia and hypotension are present, intravenous therapy should be instituted. When in doubt it would be safer to commence intravenous treatment and review the treatment daily.
 
Duration of treatment
Except for a few conditions, the optimum duration of antibiotic treatment is unknown. Many antibiotics are often presribed for a duration of 5-7 days. Nevertheless it is reasonable to discontinue therapy even after a shorter period if the patient's symptoms have resolved. There are however certain infections where prolonged treatment is necessary (Table I). In some conditions eg uncomplicated cystitis in women and gonococcal urethritis in males, single dose regimens have been shown to be effective.

Table I. Conditions where a minimum duration of treatment has been established.

Infection

Minimum duration of treatment

Tuberculosis

4 -6 months

Empyema and lung abscess

4 - 6 weeks

Endocarditis

4 weeks

Osteomyelitis

4 weeks

Atypical pneumonia

2 - 3 weeks

Pneumococcal meningitis

7 days

Pneumococcal pneumonia

5 days

Monitoring efficacy
Early review of response
A routine early review ( 3 days after commencing treatment) of the patient's response is important in order to ensure that the patient is receiving appropriate treatment. After review the doctor will have to decide whether to:

i) continue with the present regimen
ii) increase the level of treatment by changing from oral to parenteral; increasing the dose or
    changing   to a broader spectrum antibiotic
iii) decrease the level of treatment by changing from parenteral to oral, decreasing the dose or
     changing to a more specific narrow spectrum antibiotic
iv) stopping the antibiotic if the infection has resolved; the objective of treatment is achieved or
     the diagnosis has been changed.
 
Inconsistent microbiology reports
If the patient is responding there is no necessity to change antibiotic even when the laboratory reports a resistant organism. The isolate in question could have been a coloniser or a contaminant. Infections may resolve spontaneously and the antibiotic could have affected the bacteria in a way that makes it more susceptible to the host's immune defenses.

If the patient's condition fails to improve, a change in antibiotic may be necessary even when the laboratory reports a sensitive organism.
 
Causes of non-response to antibiotics
A patient may fail to respond to an antibiotic for a number of reasons which include:

i) the aetiological agent is resistant to the antibiotic
ii) the diagnosis is incorrect
iii) the choice of antibiotic is correct but the dose and/or route of administration is wrong
iv) the antibiotic cannot reach the site of infection
v) there is a colletion of pus that should be drained surgically or a foreign body/devitalised
    tissue that should be removed
vi) there is secondary infection
vii) antibiotic fever
viii) non-compliance of the host
 
Changing from intravenous to oral
Wherever feasible intravenous therapy should be changed to oral therapy. The oral antibiotic (not necessarily the oral preparation of the intravenous antibiotic) should be selected based on clinical and laboratory findings. Similarly one should not hesitate to revert to intravenous therapy if the patient's condition warrants it.
 
References:

1. Kass E H. Antimicrobial drug usage in general hospitals in Pennsylvania. Ann Int
    Med 1976; 89 : 802 - 805.
2. Lim V K E, Cheong Y M and Suleiman A B. Pattern of antibiotic usage in hospitals
    in Malaysia. Singapore Med J 1993; 34 : 525 - 528.
3. Ackerman V P, Pritchard R C, Groot Obink D J, Bradbury R and Lee A.
    Consumer survey on microbiology reports. Lancet 1979; i : 199 - 203.
4. Cooke D, Salter A J and Phillips I. Antibiotic misuse, antibiotic policies and
     information resources. J Antimicrob Chemother 1980; 6 : 435 - 443.
5. Obaseiki-Ebor E E, Akerele J O and Ebea P O. A survey of outpatient prescribing
    and antibiotic self medication. J Antimicrob Chemother 1987; 20 : 759 -763.
6. Aswapokee N, Vithayapichet S and Heller R F. Pattern of antibiotic use in medical
    wards of a University Hospital, Bangkok, Thailand. Rev Infect Dis 1990; 12 : 136 -
    141.
7. Cheong YM, Lim VKE, Jegathesan M and Suleiman AB. Med J Malaysia 1994; 47
    :
8. Kunin C M, Lipton H L, Tupasi T, Sacks T, Scheckler W E, Jivani A, Goic A,
    Martin R  R, Guerrant R L and Thamlikitkul V. Social, behavioural and practical
    factors affecting antibiotic use worldwide: Report of task force 4. Rev Infect Dis
    1987; 9 (Suppl 1) : S270 - S285.
9. Fourth Western Pacific Congress on Chemotherapy and Infectious Diseases.
    Consensus statement on policies and strategies for promoting appropriate antibiotic
     use. Manila, 1994.
8. Williams J D. Antibiotic policy. Scan J Infect Dis 1986; Supplement 49 : 175 -181

ANTIBIOTIC GUIDELINES 1996

GUIDELINES ON ANTIBIOTIC THERAPY

The following guidelines are issued for the more common infections only. However even for common infections they may not apply to certain patients. When in doubt always seek a second opinion. The recommendations for first and second choice regimens are based on a global assessment of efficacy, adverse effects , prevailing sensitivity patterns and cost. It should also be noted that guidelines such as these have to be reviewed and updated from time to time.

NOTE :

1. Erythromycin may be substituted for by a newer macrolide.
2. Gentamicin may be substituted for by another aminoglycoside depending on the
    local prevailing sensitivity pattern.
3. Where ampicillin is recommended amoxycillin may also be used.
    Ampicillin/amoxycillin may be substituted for by a betalactam/betalactamase
    inhibitor combination depending on the local prevailing sensitivity pattern.
4. Cloxacillin is the drug of choice for severe methicillin-sensitive Staphylococcus
    aureus. For oral therapy flucloxacillin is preferred to cloxacillin as the former is
    more reliably absorbed and achieves higher tissue levels. In some children who
    cannot tolerate cloxacillin a first or second generation cephalsoporin may be used.
5. Quinolones are not recommended in children.

Abbreviations:

1o : First generation
2o : Second generation
3o : Third generation

Table 1.    RESPIRATORY INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Acute pharyngitis/tonsillitis, scarlet fever 
(Streptococcus pyogenes suspected or proven)
Penicillin V Erythromycin The majority of sore throats are viral in origin and antibiotics are not indicated for treatment or prevention of secondary bacterial infections.
Diphtheria 
(Corynebacterium diphtheriae)
Benzylpenicillin   Antibiotics are not the mainstay of treatment. Antitoxin and supportive treatment are critical in management. 
Close contacts should receive erythromycin. Non-immunised contacts should be immunised.
Acute otitis media and acute sinusitis 
(Strep pneumoniae, Haemophilus influenzae & Moraxella catarrhalis)
Ampicillin 
or 
Betalactam/ 
betalactamase inhibitor combination
New macrolides Most strains of Strep pneumoniae and Haemophilus influenzae in Malaysia are sensitive to ampicillin. However many strains of Moraxella catarrhalis are resistant to ampicillin.
Acute epiglottitis 
(Haemophilus influenzae)
Chloramphe-nicol Ampicillin or 
3o cephalo-sporin 
Acute epiglottitis is a medical emergency and hospitalisation with aggressive therapy is required
Pertussis 
(Bordetella pertussis)
Erythromycin   Antibiotic treatment does not significantly alter the course of disease. If given early it helps to eradicate oropharyngeal organisms thus interrupting transmission.

 

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Acute bronchitis 
( 2o bacterial infections due to Streptococcus pneumoniae & Hae-mophilus influenzae)
Ampicillin Erythromycin 
or 
Doxycycline (adults only)
Acute bronchitis is primarily a viral infection and antibiotics are not indicated. However 2o bacterial infection may occur in severe cases. 

Erythromycin is preferred if Mycoplasma is suspected on epidemiological or other grounds.

Acute exacerbations of chronic bronchitis 
(Streptococcus pneumoniae, Hae-mophilus influenzae, Moraxella catarrhalis)
Ampicillin 
or 
Betalactam/ 
betalacta-mase inhibitor combination
Erythromycin 
or 
Doxycycline 
(adults only)
 
Acute bronchial asthma Antibiotics are not indicated   There is no evidence that antibiotics will significantly alter outcome.
Pneumonia 
Community acquired pneumonia - mild to moderate 
(Streptococcus pneumoniae, Hae-mophilus influenzae, Mycoplasma

Community acquired pneumonia - severe 
(Streptococcus pneumoniae, Hae-mophilus influenzae, Staphylococcus aureus, Klebsiella pneumoniae)

Benzylpenicillin 
or 
Ampicillin 
or 
Erythromycin 
 
 
 
 
 

Benzylpenicillin and 
Gentamicin 
or 
2o or 3o Cephalo-sporin

 
 
 
 
 
 
 
 
 
 

Betalactam/ 
betalacta-mase inhibitor combination

Erythromycin is preferred when Mycoplasma is suspected. 
 
 
 
 
 
 
 
 

When Staph aureus is suspected or demonstrated use cloxacillin and gentamicin.

Atypical pneumonia 
(Mycoplasma pneu-moniae, chlamydia, Legionella)
Erythromycin or 
Doxycycline (for adults)
   
Chlamydia trachomatis penumonia in infancy Erythromycin   Transmitted from mother. Usually becomes clinically apparent 2 - 20 weeks after birth.

 

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Nosocomial pneumonia 

Post-operative/coma 
(aerobic gram negative bacilli, streptococci, anaerobic mouth flora, Staphylococcus aureus

severe cases 

where MRSA is demonstrated or strongly suspected 

ventilated patients 
(Pseudomonas aeruginosa, other aerobic gram negative bacilli) 

immunosuppressed 
(aerobic gram negative bacilli and Staphylo-coccus aureus

  

Benzylpenicillin and 
Gentamicin 

  

  

  
3o Cephalo-sporin and 
Gentamicin 
Vancomycin 
 

Gentamicin  
and  
a 3o Cepha-losporin 

  
Gentamicin  
and  
a 3o Cephaloporin 
or  
Ureido-penicillin or 
Carbapenem

    

  

  

  

  

  

 If vancomycin is not available a combination of fucidin and rifampicin may be used 
 
 
 
 
 
 
 

Pneumonia in the immunocompromised may also be caused by a variety of non-bacterial agents eg fungi (Candida, Aspergillus ), Toxoplasma, Pneumocystis and viruses.  

  

  

 

Lung abscess/ empyema 
(mixed infection of anaerobes, Staphylococcus aureus, Streptococcus pneumoniae and aerobic gram negative bacilli) 
 
  

Benzylpenicillin and  
Gentamicin  
and Metronida-zole

    

Empyema in childhood is nearly always due to staphylococci. Where staphylococci is suspected substitute cloxacillin for benzyl penicillin

 

Table 2.    URINARY TRACT INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Acute urinary tract infection 
(E. coli, Staphylococcus saprophyticus)
Cotrimoxa-zole  
or 
Trimethoprim 
or 
Ampicillin  
or 
Nitrofurantoin 
1o/2o cephalo-sporin Many hospital acquired pathogens are now resistant to ampicillin. 
In uncomplicated cystitis in adults 4 tabs cotrimoxazole in a single dose has been shown to be effective. 
In pregnancy ampicillin should be given for 10 days
Pyelonephritis and complicated urinary tract infection 
(E. coli, other Enterobacteriaceae)
2o Cephalo-sporin  
and  
Gentamicin 
or 
a quinolone
  In all cases an attempt should be made to exclude any underlying abnormality
Recurrent urinary infection 
(E. coli, other Enterobacteriaceae, enterococci)
Cotrimoxazole 
1 tab nightly 
or 
Nitrofurantoin 
50 mg nightly
Ampicillin 
500 mg nightly 
or 
Cephalexin 
250 mg nightly 
or 
Nalidixic acid 
500 mg nightly
Recurrent urinary tract infections may require very prolonged prophylaxis. 
Female patients should be advised on perineal hygiene and micturition after intercourse. 
Treat current infection before starting on prophylaxis. 
Cotrimoxazole should be avoided during the 3rd trimester of pregnancy.
Catheter associated 
infections 
(Enterobacteriaceae, Pseudomonas and Enterococcus)
Treat accord-ing to culture & sensitivity report   Isolation of bacteria in urine culture per se is not an indication while catheter is in-situ. Antibiotics will not eradicate the bacteria and may promote resistance instead. 
Treatment is only necessary is systemic signs are present and based on the most recent culture. Catheter care is all important. Bladder irrigation is generally not useful and may introduce infection. 
The catheter should be removed as early as it is possible. 
If the catheter is changed in the presence of bacteriuria, a single prophylactic dose of antibiotic should be given 30 minutes before the procedure.
Acute urinary infection in children 
(E. coli and other Enterobacteriaceae) 

Mild 

  

  

  
 
Severe

  

  

  
Cotrimoxa-zole 
or 
Ampicillin 
or 
Oral 1o cephalo-sporin 

2o/3o cephalosporin 
or 
aminoglycoside

  In all cases assessment of renal function (cystograms, ultrasound of kidneys, ureters and bladder) should be performed. 
Prophylactic antibiotics for children < 4 years is recommended in cases where anatomical abnormalities are detected.

 

Table 3.    SKIN AND SOFT TISSUE INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Impetigo 
(Strep pyogenes, Staph aureus)
Penicillin Erythromycin 
or 
Cloxacillin and Penicillin 
or 
Cephalexin
Mupirocin ointment may be considered for topical use in cases of MRSA infections.
Boils and carbuncles 
(Staph aureus)
Erythromycin Cloxacillin 
or 
Cephalexin
Surgical drainage is the definitive mode of treatment and antibiotics may not be necessary if drainage is adequate.
Cellulitis/Erysipelas/ 
Lymphangitis 
(Strep pyogenes) 
Severe cases 

  

Mild to moderate cases 

  
Facial and orbital cellulitis in children (Haem influenzae)

Benzylpenicillin  
or 
Procaine 
penicillin 
 

Penicillin V 
or 
Erythromycin 
 
 

2o or 3o Ceph-alosporin 

  

 

  

Change to oral therapy once patient's condition improves. 
If staphylococci suspected or proven use a combination of penicillin and cloxacillin

Decubitus ulcers 
(Enterobacteriaceae, Pseudomonas, Enterococcus, anaerobic bacteria)
Antibioticsare not indicated unless systemic symptoms are present.   2o Cephalosporin and Metronidazole may be used in cases with systemic symptoms
Diabetic foot infections 
(Polymicrobial infection - Enterobacteriaceae, Staph aureus, streptococci, anaerobic bacteria)
2o or 3o Cephalo-sporin  
and Metronida-zole 
or 
Betalactam-betalacta-mase inhibitor combination
Cloxacillin  
and  
Gentamicin  
and 
Metronida-zole
Diabetic foot infections may involve extensive tissue and bone necrosis. 

Surgical debridement is often necessary. 

The duration of treatment depends on the response. 

Infected bites 
(animal bites : Pastuerella multocida, staphylococci 

human bites : mouth flora)

Ampicillin 
and/or  
Cloxacillin
Erythromycin Tetanus toxoid should be administered to patients requiring a booster. 

The value of antibiotic prophylaxis in clinically uninfected bites is not proven. For hand wounds and extensive injuries a 5 day course of antibiotics is advised. 

Human bites may have medicolegal implications and proper documentation including photographs may be necessary.

Umbilical sepsis     Antibiotics are generally not indicated. 
Where there is evidence of spread a course of cloxacillin is recommended.
Lymphadenitis 
(Staph aureus, Strep pyogenes)
Cloxacillin 
or 
Erythromycin 
or 
1oCephalosporin 
   

 

Table 4.    MUSCULOSKELETAL INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Acute osteomyelitis 
(Staph aureus - commonest; others include Enterobacteriaceae, Pseudomonas

In children < 5 yr staphylococci, streptococci and Haem influenzae

Cloxacillin Fusidic acid For children < 5 yr use a combination of cloxacillin and 2o/ 3o Ceph-alosporin  

 

Chronic osteomyelitis 
(Staph aureus, Enterobacteriaceae, Pseud aeruginosa)
Cloxacillin  Fucidic acid  
and 
Rifampicin 
or according to culture report
Where MRSA is suspected or proven, fucidic acid and rifampicin should be 1st choice antibiotics. 

For cases due to Pseud aeruginosa, an antipseudomonal fluroquinolone may be considered.

Septic arthritis 
( > 5 years : Staph aureus; < 5 years : Staph aureus, Haem influenzae)
Cloxacillin   For children < 5 yr use a combination of cloxacillin and 2o/ 3o Ceph-alosporin  

 

Compound fractures 
(Staph aureus, gram negative bacilli) 

Grade I fractures 

  

Grade II fractures 

  

  

  

Grade III fractures

  

  

2o or 3o Ceph-alosporin 
 

2o or 3o Ceph-alosporin 
and 
Gentamicin 
2o or 3o ceph-alosporin 
and 

Gentamicin 
and 
Metronidazole

  The optimum duration of antibiotic administration has not been established. No differences have been shown in 1,3 or 5 day courses. 

Infection is more likely in Grade 3 fractures with severe soft tissue and vascular injuries. Routine cultures should be taken and the antibiotics changed if necessary. This especially so for cases where surgery is delayed. 

Early surgical debridement and adequate fracture stabilisation within 6-8 hours of injury is the most important aspect of treatment.

Gas gangrene 
(Clostridium sp)
Benzylpenicillin   Use 4 mega 6 hrly

 

Table 5.     GASTROINTESTINAL INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Gingivitis 
(Spirochaetal organisms, streptococci and oral anaerobes)
Penicillin V 
and 
Metronida-zole
   
Periodontal infections 
(Streptococci and oral anaerobes)
Penicillin V Erythromycin  
Oral thrush 
(Candida albicans and other candida species)
Syrup Nystatin Azole (oral gel)  
Acute cholecystitis 
(Enterobacteriaceae, Enterococcus and Bacteroides)
2o or 3o Ceph-alosporin 
with or without 
Metronidazole
Gentamicin 
with or without 
Metronidazole
 
Acute cholangitis 
(Enterobacteriaceae, Bacteroides)
Ampicillin  
or 
2o or 3o Ceph-alosporin
Gentamicin  
Acute peritonitis 
Primary (children) 
(Strep pneumoniae, other streptococci, staphylococci, Enterobacteriaceae
Primary (adults with cirrhosis) 
(Enterobacteriaceae) 

Secondary 
(polymicrobial infection due to Enterobacteriaceae, Enterococcus and Bacteroides)

Penicillin and gentamicin 

  

  
3o Cephalo-sporin 

  

  
2o/3o cephalo-sporin and methronida-zole

3o Ceph-alosporin 

  

  

Gentamicin 

  

  
Gentamicin 
and 
Metronida-zole

 
Antibiotic associated colitis 
(Clostridium difficile)
Vancomycin (oral) 
or 
Metronidazole
   
Enteric fever 
(Salmonella typhi, Salmonella paratyphi)
Chloramphe-nicol 
or 
Cotrimoxazole 
or 
Ceftriaxone
Ampicillin 
or 
Quinolone
The majority of strains of Salmonella typhi isolated in Malaysia are still sensitive to chloramphenicol. 
The newer fluoroquinolones have been shown to be effective for the treatment of carriers.
Acute uncomplicated diarrhoeas 
(viruses, E. coli, Salmonella sp, Shigella sp, Campylobacter)
No antibiotic necessary   Oral rehydration salt solutions (ORS) should be given for replacement therapy. Salmonella sepsis is not uncommon in severely ill infants and a 3o cephalosporin is indicated when suspected.

 

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Cholera 
( Vibrio cholerae O1, O139)
Doxycycline for 4 days   Replacement of fluids and correction of electrolyte imbalances are the mainstay of treatment. 
Use syrup tetracycline in children.
Bacterial dysentery 
(Shigella, Salmonella, enteroinvasive E. coli)
Cotrimoxazole (Only in severe dysentery)   Shigella in Malaysia is often resistant to multiple antibiotics. For such strains the use of a quinolone may be considered.
Amoebic dysentery 
(Entamoeba histolytica)
Metronidazole Tinidazole  
Liver abscess 
Pyogenic  
(coliforms, staphylococci, micro-aerophilic streptococci) 

Amoebic 
(Entamoeba histolytica)

Ampicillin 
and 
Metronida-zole 

  

  

Metronida-zole

2o or 3o ceph-alosporin 
and 
Metronida-zole 
 
 
 

Tinidazole

 

 

Table 6.    GENITOURINARY INFECTIONS (INCLUDING SEXUALLY TRANSMITTED DISEASES)
Note : For all sexually transmitted diseases every effort should be made for contact tracing and treatment of the sexual partners.

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Pelvic inflammatory disease 
(anaerobic bacteria, streptococci, Entero-bacteriaceae, chlamydia, Neisseria gonorrhoeae
Mild to moderate 

  

  

Severe

  

  

  

  

Doxycycline 
and 
Gentamicin 
and 
Metronida-zole 

Doxycycline 
and 
2o or 3o cephalo-sporin 
and 
Metronida-zole

   
Vaginitis 
Candidal 
(Candida albicans, Candida tropicalis, other Candida spp) 

  
Trichomonal 
(Trichomonas vaginalis

Bacterial vaginosis 
(Gardnerella vaginalis, Mobiluncus, Bacteroides sp)

  

Nystatin 
or 
Clotrimazole 

  

Metronida-zole 
or Tinidazole 
 

Metronida-zole 
or 
Tinidazole

  

Fluconazole 
or Ketoconazole 
or Itraconazole 

  

  

  
 

Ampicillin

  

  

  
 

  
Metronidazole should be avoided during the first trimester. 

  
With recurrent infections consider treatment for the sexual partner as well.

Gonorrhoea 
(Neisseria gonorrhoeae) 
Uncomplicated urethritis, rectal and pharyngeal gonorrhoea 

  
  
Pelvic inflammatory disease 

  
 

Adult gonococcal ophthalmia 

  

  
Gonococcal ophthalmia neonatorum

  

Spectino-mycin 
or 
Ceftriaxone 
or 
Ciprofloxacin 

  

Spectino-mycin 
or 
2o or 3o Cephalo-sporin 
 

Ceftriaxone 
or 
Spectino-mycin

    

For uncomplicated urethritis, rectal and pharyngeal gonorrhoea single dose treatment is sufficient. 

  

  
For other forms of gonorrhoea, three day courses are required. 

  

  

  
 

In gonococcal ophthalmia parenteral antibiotics should be accompanied by hourly conjunctival irrigation with saline or antibiotic eyedrops.

Non-gonococcal urethritis 
(Chlamydia tra-chomatis, Ureaplasma urealyticum) 
Doxycycline 
or 
Erythromycin 

 

  Doxycycline or erythromycin should be given for at least seven days. 
With certain newer macrolides single dose regimens have been shown to be effective.
Inclusion conjunctivitis (adults) 
(Chlamydia tra-chomatis)
Doxycycline 
or 
Erythromycin
  Duration of treatment should be fourteen days.
Syphilis 
(Treponema pallidum

Early 

  

  
 

  
Late 

  

  
  
Neurosyphilis 

  

  
Congenital syphilis 

 

  

  

Procaine penicillin (10 days) or 
Benzathine penicillin ( 2 weekly doses) 

Procaine  
penicillin (21 days) or 
benzathine penicillin (3 weekly doses) 
 

Procaine or Benzyl pencillin (21 days) 

Benzyl-penicillin

  For patients allergic to penicillin 

  

Erythromycin or doxycycline for 30 days 

  

  

  
Erythromycin or doxycycline for 30 days 

  
 

Doxycycline for 30 days 

  
 

Asymptomatic babies born of syphilitic mothers should also be treated

Chancroid 
(Haemophilus ducreyi)
Cotrimoxazole or 
Ceftriaxone
  Bubos should be aspirated, not incised and drained.

 

Table 7.    CENTRAL NERVOUS SYSTEM INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Meningitis  (Haemophilus influen-zae, Streptococcus pneumoniae, Neisseria meningitidis

Adult 

  

  

  
  
Children 

  

  
Neonatal meningitis

  

  

  

  
Benzyl penici-llin and Chlor-amphenicol 
or 
3o Cephalo-sporin 

Ampicillin and 
Chloramphe-nicol 
or 
3o cephalo-sporin 

Ampicillin and gentamicin 
or 
3o cephalo-sporin

  When the pathogen is known the antibiotic of choice for pneumococcal and meningococcal meningitis is benzyle penicillin. For haemophilus meningitis chloramphenicol or a 3o cephalosporin is the drug of choice. 

Meningitis caused by penicillin resistant pneumococci and ampicillin/chloram-phenicol resistant haemophilus are still uncommon in Malaysia. 

Many laboratories have rapid diagnostic kits and results can often be obtained within a few hours. 

 

Cryptococcal meningitis  
(Cryptococcus neoform-ans)
Amphotericin B and 5 Flu-cytosine   Fluconazole may be considered as an alternative drug for cryptococcal meningitis.
Brain abscess (adults) 
( Streptococci, anaerobic organisms) 

Brain abscess (children) 
(Staphylococci, streptococci, gram negative aerobic bacilli and anaerobic organisms)

Benzylpenicillin 
and 
Metronidazole 
 

Cloxacillin 
and 
3o cephalo-sporin 
and 
Metronidazole

3o Cephalo-sporin 
and 
Metronidazole
Surgical drainange is the definitive treatment for brain abscess.

 

Table 8.    CARDIOVASCULAR INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Endocarditis 
Non-intravenous drug user 
(Streptococcus viridans group) 

Intravenous drug user 
(Staphylococcus aureus

  

  

Post-surgical endocarditis 
( Staphylococci, diphtheroids)

Benzylpenicillin  
and 
Gentamicin 

  

Cloxacillin  
and 
Gentamicin 

  

  

  

Cloxacillin 
and 
Gentamicin

  Dosage: 
Penicillin 2-3 mega iv, 4-6 hrly for 4-6 weeks 
Gentamicin 1.0 mg/kg iv, 8 hrly for 2-6 weeks 
Cloxacillin 2 g iv, 4hrly for 6 weeks. 
After 4 weeks of iv penicillin, replacement with oral penicillin plus probenecid can be considered. 
When endocarditis is shown to be due to Enterococcus use ampicillin 2 g iv 6hrly and gentamicin for 6 weeks
Endocarditis in IDUs often involves the tricuspid valves and associated with pneumonia/lung abscess. 
Endocarditis in IDUs may occasionally be caused by gram negative bacilli in which case treatment should be based on the sensitivity report. 
For MRSA infections use vancomycin or a combination of fucidic acid and rifampicin. 
Staphylococcus epidermidis is often resistant to cloxacillin thus vancomycin may have to be used instead. 
Other bacteria and fungi can also cause post-surgical endocarditis and treatment will be according to culture report. 
Surgical intervention is often necessary for prosthetic valve infection.

 

Table 9.    BACTERAEMIA AND SEPTICAEMIA

Condition (According to most likely focus

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Urinary (community acquired - Enterobact-eriaceae, Enterococcus

Urinary (hospital acquired - Pseudomonas and other gram negative aerobic bacilli)

Ampicillin 
and  
Gentamicin 
 

2o or 3o generation Cephalo-sporin 
and 
Gentamicin

   
Gall bladder/bowel 
(Enterobacteriaceae, Enterococcus, anaerobic organisms)
3ogeneration Cephalo-sporin 
and 
Metronida-zole
Gentamicin 
and 
Metronida-zole 
or 
Betalactam-betalactamse inhibitor combination and gentamicin
 
Female pelvis 
(Enterobacteriaceae, Enterococcus, anaerobic organisms)
Gentamicin 
and 
Metronida-zole
2o or 3o generation Cephalo-sporin 
and 
Metronida-zole
 
Skin (cellulitis) 
(Streptococcus pyogenes

Skin (abscess) 
(Staphylococcus aureus) 

Decubitus ulcers, diabetic foot ulcers 
(Aerobic gram negative bacilli, anaerobic bacteria, staphylococci)

Benzylpenicillin 
 
 

Cloxacillin 

  

Cloxacillin 
and 
Gentamicin 
and 
Metronidazole

  

  

  

  

  

  

  Betalactam-betalactamse inhibitor combination and gentamicin

 
Intravascular lines 
(Staphylococci, Enterobacteriaceae)
Cloxacillin 
and 
Gentamicin
  The infected line should be removed. 
Where MRSA and MRSE are prevalent use vancomycin or a combination of fucidic acid and rifampicin.
Lung - community acquired 
(Staphylococcus aureus) 
  
Lung - hospital acquired 
(Staphylococcus aureus, aerobic gram negative bacilli)
Cloxacillin 
and 
Gentamicin 

  
Cloxacillin 
and 
Gentamicin 
and 
Metronida-zole

  

  

  
  

3o generation Cephalo-sporin 
and 
Gentamicin and Metronida-zole

 

Condition (According to most likely focus

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Neutropaenic 3o generation Cephalosporin and 
Gentamicin
Ureidopeni-cillin 
or 
carbapenem 
and 
Gentamicin 

  

 

In a significant proportion of neutropaenic patients cultures are negative. 
Many authorities would recommend commencement of antifungal treatment if there is no response after 3 - 5 days of antibacterial treatment.

 

Table 10.    OTHER INFECTIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Scrub typhus 
(Rickettsia tsutsugamushi)
Tetracycline (to be given until at least 48 hours after fever has subsided) 
or 
Doxycycline for 3 days
  If treatment is initiated before the fifth day of clinical disease, a further 3 day course 4 days later is required to prevent relapse.
Melioidosis 
(Burkholderia pseudomallei)
Ceftazidime for 14-21 days 
followed by 
Doxycycline 
or 
Cotrimoxazole 
or Amoxycillin/clav-ulanic acid for 3 months
  Treatment for longer than 3 months may be necessary for some cases

 

Table 11.    INFECTIONS ASSOCIATED WITH PREGNANCY
Antibiotics should be used with care in pregnancy. Beta-lactam antibiotics and macrolides are probably the safest antibiotics to use in pregnancy.

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Asymptomatic bacteriuria/ Cystitis 
( E. coli )
Ampicillin 
or 
Cephalexin
   
Acute pyelonephritis 
( E. coli )
2o or 3o generation Cephalo-sporin Ampicillin  

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Chorioamnionitis/ 
Prolonged rupture of membranes 
(Group B streptococci, anaerobes, Enterobacteriaceae)
2o or 3o generation Cephalosporin 
and 
Metronidazole
Ampicillin 
and 
Gentamicin 
and 
Metronidazole
 
Puerperial and post-abortal sepsis 
(Streptococci, Entero-coccus, staphylococci, Enterobacteriaceae, anaerobes)
2o or 3o generation Cephalosporin 
and 
Metronidazole
Ampicillin 
and 
Gentamicin 
and 
Metronidazole
 

 

 Table12.    CHEMOPROPHYLAXIS FOR SELECTED MEDICAL CONDITIONS

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Rheumatic fever Benzathine penicillin 1.2 mega every 4 weeks Penicillin V  
250 mg 12 hrly 
or 
Erythromycin 
250 mg 12 hrly
Prophylaxis should be maintained for many years. Children should continue to receive prophylaxis until the age of 25 years and adults for at least 5 years whichever is the longer.
Cholera Tetracycline  
1 g daily for 5 days 
or 
Doxycycline 200 mg stat dose
   

  

Condition

1st Choice antibiotic(s)

2nd Choice antibiotic(s)

Notes

Bacterial endocarditis 
For dental and upper respiratory procedures 

  

  

For patients who have prosthetic valves or previous endocarditis undergoing dental and upper respiratory procedures; and for patients undergoing genitourinary manipulation 

  

For patients with prosthetic valves undergoing cardiac catheterisation, pace-maker insertion and skin biopsy

Amoxycillin 3 g oral 1 hour before procedure 
or 
Ampicillin 1 g iv just before pro-cedure followed by 500 mg 6 hrs later 

Ampicillin 1 g iv just before procedure followed by 500 mg 6 hrs later and 
Gentamicin 1.5 mg/kg iv just before procedure and I dose 6 hr later 
 

Cloxacillin 1 g iv and 
Gentamicin 1.5 mg/kg iv 
just before procedure

  Patients allergic to penicillin 
Erythromycin 1.5 g orally 1 hour before procedure folowed by 500 mg 6 hours later 
or 
Vancomycin 1 g iv just before procedure 

  

Dosages for children: 
Amoxycillin 50mg/Kg before and 25 mg/Kg after 
Gentamicin 2 mg/Kg before 
Cloxacillin 50 mg/Kg before 
 

Clindamycin is preferred in patients on long term penicillin

Post splectomised children Penicillin V 250 mg 12 hrly 
or 
Benzathine penicillin 1.2 mega monthly
  Pneumococcal vaccine should be given to the patient one month before splenectomy
Close contacts of meningococcal and haemophilus meningitis 
patients
Adults (menin-gococcal only) 

Rifampicin 600 mg 12 hrly for 2 days 

Children ( Men-ingococcal and haemophilus) 

Rifampicin  
10 mg/kg/day  
12 hrly for 4 days

  In meningococcal meningitis treatment of the patient with penicillin may not reliably clear the nasopharynx of meningococci. A prophylactic course of rifampicin is advised for the convalescent patient before discharge back to the family circle.

 

SURGICAL CHEMOPROPHYLAXIS
The use of antibiotic prophylaxis has been shown to prevent post-surgical wound infections. When employed rationally significant reductions in morbidity and mortality and savings in resources can be achieved. However when used excessively and in situations when its benefit has not been proven, perioperative antibiotics can lead to unjustifiably high costs of medical care. Single dose regimens or very short courses are unlikely to lead to emergence of bacterial resistance but routine prolonged courses have been clearly associated with increased rates of resistance.

Surgical operations can be divided into four broad categories :

Prophylaxis is generally recommended for clean-contaminated and contaminated operations. In clean operations prophylaxis maybe justified if the consequence of infection is very serious eg in cardiac operations and orthopaedic implants.

Another factor which should be considered in determining probability of infection is the patient himself. Factors that reduce host defenses eg old age, malignancy, malnutrition, steroid therapy, etc will increase the risk of infection.
 
 In using antibiotics for surgical chemoprophylaxis the following principles should be adhered to:

1. It is important to distinguish between prophylaxis and treatment. Prophylaxis is given
    when no infection exists previously. When an infection is already present, even when
    clinically not evident, treatment should be given.
2. Prophylaxis should be given only in certain conditions where the benefits clearly
    outweigh the risks. The cost of prophylaxis should also be considered.
3. The antibiotic should be directed at the most likely contaminating organism for that
    particular procedure. Choice of antibiotic will also depend on whether the patient
    has been in hospital for a prolonged period and the current pattern of antibiotic
    resistance in the hospital. In general the agent selected should (a) be of low toxicity (b) have an
    established safety record (c) reach a useful concentration in the relevant tissues.
4. The route of administration, timing and duration of giving the antibiotic is planned to
    achieve the maximum concentration of the antibiotic in the tissues during and shortly
    after the operation. Antibiotics are preferably given by the intravenous route at the
    time of induction of anaesthesia. In most instances a single pre-operative dose would
    suffice. Where surgery is prolonged additional intraoperative doses may be given.
    There is no evidence that there is any benefit in extending prophylaxis beyond 24
    hours after the operation.
5. Topical antibiotics are not recommended with the exception of opthalmic surgery
    and cases of extensive skin loss.
6. Surgical chemoprophylactic regimens should be reviewed regularly and changes
    made if necessary.
 

GUIDELINES FOR SURGICAL ANTIBIOTIC PROPHYLAXIS

Gynaecologic surgery

Operative procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Caesarean section 
(anaerobes, streptococci, aerobic gram-negative bacilli)
2o or 3o cephalosporin 1. Gentamicin and Metronidazole 
2. Ampicillin and Metronidazole
Hysterectomy 
(anaerobes, streptococci)
2o or 3o cephalosporin Ampicillin and Metronidazole

 
General Surgery

Operative procedure

1st Choice antibiotic (s)

2nd Choice antibiotic(s)

Cholecystectomy (open and laparoscopic) 
(Aerobic gram-negative bacilli, enterococci, anaerobes)
2o or 3o cephalosporin 1. Beta-lactam/beta-lactamase inhibitor 
2. Gentamicin
Oesophageal/gastric surgery 
(Aerobic gram-negative bacilli, streptococci)
2o or 3o cephalosporin Beta-lactam/betalactamase inhibitor
Colorectal surgery 
(Anaerobes, aerobic gram-negative bacilli, enterococci)
2o or 3o cephalosporin 
and 
Metronidazole
Gentamicin and Metronidazole
Appendicectomy 
(Anaerobes, aerobic gram-negative bacilli, enterococci)
2o or 3o cephalosporin 
and 
Metronidazole
Gentamicin and Metronidazole

Vascular Surgery

Operative procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Arterial replacement/ by-pass surgery 2o cephalosporin Cloxacillin and Gentamicin

Cardiac Surgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Valve replacement and coronary grafts 2o or 3o cephalosporin  

 
Thoracic Surgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Lobectomy and pneumonectomy 2o or 3o cephalosporin  

 
Orthopaedic Surgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Arthroplasty and joint replacements 
(Staphylococci)
Cloxacillin and Gentamicin 2o cephalosporin
Open reduction of fractures 
(Staphylococci)
Cloxacillin and Gentamicin 2o cephalosporin

ENT Surgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Major oral, head and neck surgery 
(streptococci, anaerobes, aerobic gram-negative bacilli)
2o or 3o cephalosporin 
and 
Metronidazole
 

Neurosurgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Craniotomy 
(Staphylococci)
2o cephalosporin Cloxacillin and Gentamicin
Shunt procedures 
(Staphylococci)
2o cephalosporin Cloxacillin and Gentamicin

Urological surgery

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Stone surgery and prostatectomy 
(Enterobacteriaceae)
2o or 3o cephalosporin Gentamicin

   
Endoscopic procedures
Antibiotic prophylaxis for endoscopic procedures are given for 2 main reasons:
1) to prevent endocarditis (see table below for degree of risk)
2) to prevent infective complications
 

Operative Procedure 1st Choice antibiotic(s) 2nd Choice antibiotic(s)
Hepatobiliary, pancreatic in the presence of obstruction 
(Enterobacteriaceae)
2o or 3o cephalosporin Gentamicin
Cystoscopy, nephroscopy and stents 
(Enterobacteriaceae)
2o or 3o cephalosporin Gentamicin
Arthroscopy 
(Staphylococci)
2o cephalosporin Cloxacillin and Gentamicin

Estimated risk of endocarditis associated with preexisting cardiac disorders.
(From New Engl J Med 1995, 323:39)
 
 

Relatively high risk

Intermediate risk

Very low or negligible risk

Prosthetic heart valves  
Previous endocarditis 
Cyanotic congenital heart failure 
Patent ductus arteriosus 
Aortic regurgitation 
Aortic stenosis 
Mitral regurgitation 
Mitral stenosis and regurgitation 
Ventricular septal defect 
Coartation of the aorta 
Surgically repaired intracardiac lesions with residual haemodynamic abnormality
Mitral valve prolapse with regurgitation 
Pure mitral stenosis 
Tricuspid valve disease 
Pulmonary stenosis 
Asymmetric septal hypertrophy 
Bicuspid aortic valve or calcific aortic sclerosis with minimal haemodynamic abnormality 
Degenerative valvular disease in elderly patients 
Surgically repaired intracardiac lesions with no haemodynamic abnormality, less than 6 months after the operation
Mitral valve prolapse without regurgitation 
Trivial valvular regurgitation on echocardiography without structural abnormality 
Isolated atrial septal defect 
Arteriosclerotic plaques 
Coronary artery disease 
Cardiac pacemaker 
Surgically repaired intraccardiac lesions, with minimal or no haemodynamic abnormality, more than six months after operation

   
ANTIBIOTIC DOSAGES FOR ADULTS

Note : The following dosing guidelines are the usually recommended regimens. They may not apply to all patients nor to all infections. When in doubt always consult a specialist.

Antibiotic

Usual oral regimen

Usual parenteral regimen

Amphotericin B   0.25 - 1.5 mg/kg/day
Amikacin   7.5 mg/kg 8 hrly
Amoxycillin 250 - 500 mg 8 hrly  
Amoxycillin-Clavulanate  250 - 500 mg 8 hrly (based on amoxycillin)  
Ampicillin 250 - 500 mg 6hrly 1 - 2 g 6 hrly
Ampicillin-sulbactam (Sultamicillin)  375 - 750 mg 12hrly 1 - 2 g 6hrly or 8 hrly
Azithromycin 500 mg dly  
Bacampicillin 400 - 800 mg 12 hrly  
Carbenicillin 500 mg - 1 g 6 hrly 5 - 6 g 6 hrly
Cefoperazone   1 - 2 g 8 - 12 hrly
Cefotaxime   1 - 2 g 8 - 12 hrly
Ceftazidime   1 - 2 g 8 - 12 hrly
Ceftriaxone   500 mg - 1 g 12 - 24 hrly
Cefuroxime 250 mg 12 hrly 750 mg - 1.5 g 8 - 12 hrly
Cephalexin 250 mg - 1 g 6 hrly  
Chloramphenicol 250 - 750 mg 6 hrly 250 mg - 1 g 6 hrly
Ciprofloxacin 250 - 750 mg 12 hrly 400 mg 12 hrly
Clarithromycin 250 - 500 mg 12 hrly  
Clindamycin  150 - 300 mg 6 hrly 300 - 900 mg 6 - 8 hrly
Cloxacillin  500 mg - 1 g 6 hrly 1 - 2 g 6 hrly
Doxycycline 100 mg 12 hrly  
Erythromycin 250 - 500 mg 6 hrly 1 g 6 hrly
Fluconazole 100 - 200 mg per day 100 - 200 mg per day
Flucytosine 37.5 mg/kg 6 hrly  
Fusidic acid 500 mg 8 hrly 500 mg 8 hrly
Gentamicin   1.5 - 2 mg/kg 8 hrly
Imipenem/Cilastatin   500 mg - 1 g 6hrly
Itraconazole 100 - 200 mg per day  
Kanamycin   5 - 7.5 mg/kg 8 hrly
Ketoconazole 200 - 400 mg 12 - 24 hrly  
Metronidazole 250 - 750 mg 8 hrly 500 mg 8 hrly
Nalidixic acid 1 g 6hrly  
Netilmicin   1.5 - 2 mg/kg 8 hrly
Nitrofurantoin 50 mg - 100 mg 6 - 8 hrly  
Norfloxacin 400 mg 12 hrly  
Nystatin 0.5 - 1 million units 6 hrly  
Ofloxacin 200 - 400 mg 12 hrly  
Pefloxacin 200 - 400 mg 12 hrly  
Penicillin G (Benzylpeniciilin)   1 - 4 mega 4 - 6 hrly
Procaine penicillin   0.6 - 1.2 mega 12 - 24 hrly
Benzathine penicillin   0.6 - 1.2 mega monthly
Penicillin V 250 - 500 mg 6 hrly  
Piperacillin   3 - 4 gm 4 - 6 hrly
Rifampicin 600 mg 24 hrly 600 mg 24 hrly
Tetracycline 250 - 500 mg 6 hrly  
Tobramycin   1.5 - 2 mg/kg 8hrly
Trimethoprim-sulphamethoxazole (Cotrimoxazole) 800 mg (based on sulphamethoxazole) or 2 tabs 12 hrly  
Vancomycin   250 - 500 mg 8 - 12 hrly

Aminoglycoside dosing : There is now evidence to show that once daily dosing is as effective as multiple dosing.
 

ANTIBIOTIC DOSAGES FOR NEONATES WITH SERIOUS INFECTIONS
Note : The following dosing guidelines are for intravenous administration.

Antibiotic

Full term neonate

Premature neonate

Amikacin <7 days : 20mg/kg div. 12 hrly 
>7 days : 30 mg/kg div. 12 hrly
15 mg/kg div. 12 hrly
Ampicillin <7 days : 150 mg/kg div. 8hrly 
>7 days : 200 mg/kg div. 6 hrly
100 mg/kg div. 12 hrly
Cefotaxime <7 days : 100 mg/kg div. 12 hrly 
>7 days : 150 mg/kg div. 8hrly
100 mg/kg div. 12 hrly
Ceftazidime <7 days : 100 mg/kg div. 12 hrly 
>7 days : 150 mg/kg div. 8 hrly
100 mg/kg div. 12 hrly
Ceftriaxone <15 days : 20-50 mg/kg once daily 
>15 days : 20-80 mg/kg once daily
<15 days : 20-50 mg/kg once daily 
>15 days : 20-80 mg/kg once daily
Chloramphenicol <2 weeks : 25 mg/kg div. 8 hrly 
>2 weeks : 50 mg/kg div. 8 hrly
25 mg/kg div. 8hrly
Clindamycin  20 mg/kg div. 8 hrly 15 mg/kg div. 8 hrly
Cloxacillin  <10 days : 200 mg/kg div. 8 hrly 
>10 days : 200 mg/kg div. 6 hrly
<10 days (<2.5 kg) : 100 mg/kg div. 8hrly; >10 days (<2.5 kg) : 100 mg/kg div. 8 hrly
Gentamicin <7 days : 5 mg/kg div. 12 hrly 
>7 days : 7.5 mg/kg div. 8 hrly
5 mg/kg div. 8 hrly
Imipenem <7 days : 40 mg/kg div. 12 hrly 
>7 days : 60 mg/kg div. 8 hrly
40 mg/kg div. 12 hrly
Kanamycin <7 days : 20 mg/kg div. 12 hrly 
>7 days : 30 mg/kg div. 8 hrly
<3 days : 10 mg/kg once daily 
>3 days : 20 mg/kg div. 12 hrly
Metronidazole 15 mg/kg loading dose, then 15 mg/kg div 12 hrly  
Netilmicin <7 days : 5 mg/kg div. 12 hrly 
>7 days : 7.5 mg/kg div. 8 hrly
5 mg/kg div. 8 hrly
Penicillin G (Benzylpeniciilin) <7 days : 250,000 U/kg div. 8 hrly 
>7 days : 400,000 U/kg div. 6 hrly
250,000 U/kg div. 12 hrly
Tobramycin <7 days : 5 mg/kg div. 12 hrly 
>7 days : 7.5 mg/kg div. 8 hrly
5 mg/kg div. 8 hrly
Vancomycin <7 days : 30 mg/kg div. 12 hrly 
>7 days : 45 mg/kg div. 8 hrly
30 mg/kg div. 12 hrly

 

ANTIBIOTIC DOSAGES OF ORAL ANTIBIOTICS FOR NEONATES

Antibiotic

Daily dosage

Amoxycillin 20-40 mg/kg div. 8 hrly
Ampicillin 50-100 mg/kg div 8 hrly
Cephalexin 50 mg/kg div 6 hrly
Chloramphenicol < 14 days : 25 mg/kg div 8 hrly 
> 14 days : 50 mg/kg div. 6 hrly
Clindamycin  20 mg/kg div. 6 hrly
Cloxacillin  > 2.5 kg : 50-100 mg/kg div. 6 hrly 
< 2.5 kg : 50 mg/kg div. 8 hrly
Erythromycin < 7 days : 20 mg/kg div. 12 hrly 
> 7 days : 20-40 mg/kg div. 6 hrly
Metronidazole 25 mg/kg div. 12 hrly
Penicillin V 50,000 U/kg div. 8 hrly

 

PARENTERAL ANTIBIOTIC DOSAGES FOR SERIOUS INFECTIONS IN INFANTS AND CHILDREN

Antibiotic

Daily dosage

Aminoglycosides 
Amikacin  
Gentamicin  
Kanamycin  
Netilmicin  
Streptomycin  
Tobramycin
22 mg/kg div. 8 hrly 
7.5 mg/kg div. 8 hrly 
30 mg/kg div. 8 hrly 
7.5 mg/kg div. 8 hrly 
20 mg/kg div. 12 hrly 
5 mg/kg div. 8 hrly
Cephalosporins 
Cefoperazone  
Cefotaxime  
Ceftazidime  
Ceftriaxone
> 12 years : 150 mg/kg div. 8 hrly 
200 mg/kg div. 6 hrly 
150 mg/kg div. 8 hrly 
100 mg/kg once daily
Chloramphenicol 100 mg/kg div. 6 hrly
Clindamycin  40 mg/kg div. 6 hrly
Erythromycin 40 mg/kg div. 6 hrly
Imipenem 40-60 mg/kg div. 6 hrly
Metronidazole 30 mg/kg div 6 hrly
Penicillins 
Penicillin G  
Benzathine penicillin  
Procaine penicillin  
Ampicillin  
Cloxacillin  
Piperacillin
400,000 U/kg div. 6 hrly 
50,000 U/kg single dose im. 
50,000 U/kg div. 12 hrly im. 
200 mg/kg div. 6 hrly 
200 mg/kg div. 6 hrly 
200 - 300 mg/kg div. 6 hrly
Rifampicin 10 - 20 mg/kg div. 12 hrly
Trimethoprim-sulphamethoxazole (Cotrimoxazole) 20 mg TMP/100 mg SMX/kg div. 6 hrly
Vancomycin 40 mg/kg div. 6 hrly

 

ANTIBIOTIC DOSAGES OF ORAL ANTIBIOTICS FOR INFANTS AND CHILDREN

Antibiotic

Daily dosage

Azithromycin 10 mg/kg dly
Cephalosporins 
Cefuroxime  
Cephalexin  
Cefaclor  
Cefadroxil  
Cephradine
30 mg/kg div 12 hrly 
25 - 50 mg/kg div. 6 hrly 
20 - 50 mg/kg div 8 hrly 
30 mg/kg div 12 hrly 
25 - 50 mg/kg div 12 hrly
Chloramphenicol 50-100 mg/kg div. 6 hrly
Clindamycin  25 mg/kg div. 6 hrly
Macrolides 
Clarithromycin  
Erythromycin
15 mg/kg div. 12 hrly 
25 - 50 mg/kg div. 6 hrly
Metronidazole 25 mg/kg div 6 hrly
Nalidixic acid 50 mg/kg div 6 hrly
Nitrofurantoin 7 mg/kg div 6 hrly 
2 mg/kg single dose dly (prophylaxis)
Penicillins 
Penicillin V  
Amoxycillin  
Ampicillin  
Cloxacillin  
Amoxycillin-clavulate  
Sultamicillin
<10kg : 125 mg 8 hrly; >10 kg : 250 mg 8 hrly 
20 - 40 mg/kg div. 8 hrly 
50 - 100 mg/kg div. 6 hrly 
50 - 100 mg/kg div. 6 hrly 
20 - 40 mg/kg div. 8 hrly 
25 - 50 mk/kg div 12 hrly
Rifampicin 20 mg/kg div. 12 hrly
Trimethoprim-sulphamethoxazole (Cotrimoxazole) 6-20 mg TMP/30-100 mg SMX/kg div. 12 hrly

 



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