Resistance to nalidixic acid. A misconception due to underdosage
- 18 October 1976
- journal article
- research article
- Published by American Medical Association (AMA) in JAMA
- Vol. 236 (16), 1857-1860
- https://doi.org/10.1001/jama.236.16.1857
Abstract
The clinical impression of inordinate selection of resistant mutants to nalidixic acid cannot be substantiated on close scrutiny when sensitive infections are treated at a full dosage of 4 g/day. When 27 consecutive patients were treated with 4 g nalidixic acid/day, resistance developed in the bacteriuric population in only 7%. Resistance in the fecal reservoir was surprisingly minimal and much less than that reported for sulfonamides, tetracyclines and ampicillin. The observation is important because multiply-resistant Enterobacteriaceae maintain their sensitivity to nalidixic acid since extrachromosomal R-factor resistance to nalidixic acid was never demonstrated and cannot be transferred from 1 organism to another. In vitro data on 100 sensitive strains of Enterobacteriaceae show that the development of resistance to nalidixic acid is inversely proportional to the concentration of nalidixic acid regardless of whether the inoculum size is 105 or 108 bacteria/ml. Underdosage (< 4 g/day) with nalidixic acid is the probable cause of excessive resistance.This publication has 4 references indexed in Scilit:
- A Critical Evaluation of Nalidixic Acid in Urinary-Tract InfectionsNew England Journal of Medicine, 1966
- MECHANISM OF ACTION OF NALIDIXIC ACID ON ESCHERICHIA COLIJournal of Bacteriology, 1964
- Absorption, excretion, and metabolism of a new antibacterial agent, nalidixic acidToxicology and Applied Pharmacology, 1964
- The Effect of Inoculum Size on Inhibition Zones in Agar Media Using Staphylococci and StreptomycinJournal of General Microbiology, 1958