Human bioavailability studies demonstrates interchangeability between brands of pefloxacin tablets marketed in Nigeria having wide price margins

Objective: Several brands of pefloxacin tablets with very wide price margins are prevalent in many developing countries. We set out here to evaluate whether three popular brands (peflotab, peflaxcin-400 and paflox-400) (average cost, USD 2.4 per sachet) are bioequivalent with the innovator brand, peflacin (average cost, USD 10 per sachet). Methods: Using the Latin Square crossover design, twelve subjects were randomly assigned into four groups (three subjects per group). Subjects in each group received one tablet each of a particular brand of pefloxacin (each brand contains 400 mg pefloxacin) followed by a 10-day washout period before cross-over. Urine was collected at various intervals up to 42 hours postdosing and the pefloxacin content measured. The Fischers Least Significant Test was used to evaluate differences in urinary pharmacokinetic parameters between subjects receiving the different brands. Result: While the cumulative quantity of pefloxacin excreted within 42 hours and the maximum excretion rate of the less expensive brands (peflotab, peflaxcin-400 and paflox-400) were not significantly different from that of the expensive innovator brand, peflacin (P>0.05), only the Time for maximum urinary exretion rate for peflaxcin-400 was significantly different from that of the innovator brand (22 h for peflaxcin -400 and 6 h for peflacin). Conclusion: The three tested brands are bioequivalent and therefore interchangeable with the innovator brand, although they are more than 4 times cheaper. For developing countries, it is important to promote the use of cheaper alternative antibiotics that are bioequivalent with the often more expensive inovator brands to avoid non-compliance with prescribed medication as a result of non-affordability by the patients.