Widespread use of b-lactams has lead to development of resistant microorganisms because of production of b-lactamases(1,2). To overcome this problem, b-lactams have been combined with b-lactamase inhibitors. The spectrum of activity of each combination is determined by the b lactam. The addition of b-lactamase inhibitor does not decrease the dose of the b-lactam. The ratios of the anti-microbial drug and the enzyme inhibitor in various combinations are: (i) Amoxycillin-clavulanic acid 5 : 1 (in injectible); variable in oral preparations; (ii) Piperacillin tazobactam 8 : 1; (iii) Cefoperazone-sulbactam 1 : 1; (iv) Ampicillin-sulbactam 2 : 1.

We have come across frequent errors in administration of these combinations. Taking the example of cefoperazone-sulbactam, an instruction is written for a 10 kg child as Inj cefoperazone-sulbactam 300 mg IV 8-hourly (to give 300 mg cefoperazone). The staff takes a vial labeled as 1 g (cefoperazone content 500 mg) and dilutes the same in 10 ml diluent and administers 3 mL. However, this will deliver only 150 mg of cefoperazone. The problem is more likely to occur in pediatric patients who will receive a fraction of the vial.

Similar is the problem with oral combinations such as amoxicillin-clavulanic acid available in India. To overcome this problem, we suggest following solutions: (i) It will be preferable to mention only the amount of active drug in the injection vial/ oral preparation prominently and the contents could give the details. For example, vial of a combination of cefoperazone (500 mg)- sulbactam (500 mg), currently labeled as 1 g, could be labeled as 500 mg; (ii) The physicians and nurses should take care while prescribing / administering and should clearly mention / administer the dose of the active compound.

We will like to alert the pediatricians about this error so that they can identify this and take corrective actions.

Rakesh Lodha,
S.K. Kabra,
Department of Pediatrics,
All India Institute of Medical Sciences,
New Delhi 110 029, India.
E-mail: [email protected]  

1. Toltzis P, Blumer JL. Antibiotic resistance. In: Feigin RD, Cherry JD, Demmler GJ, Kaplan SL. Textbook of Pediatric Infectious Diseases. 5th Edn, Saunders, Philadelphia. 2004: pp 2944-2965.

2. Mathai D, Rhomberg PR, Biedenbach DJ, Jones RN. India Antimicrobial Resistance Study Group. Evaluation of the in vitro activity of six broad-spectrum beta-lactam antimicrobial agents tested against recent clinical isolates from India: a survey of ten medical center laboratories. Diagn Microbiol Infect Dis. 2002; 44: 367-377.