Gentamycin is not given orally because: September 2005: (A) Adverse effects on gastric mucosa, (B) Interferes with absorption of other drugs, (C) Rapidly destroyed by gastric acid, (D) Poor absorption
Answer is D. Ans. D: Poor absorption Like all aminoglycosides, when gentamicin is given orally, it is not systemically active. This is because it is not absorbed to any appreciable extent from the small intestine. It is administered intravenously, intramuscularly or topically to treat infections. Common propeies of aminoglycoside antibiotics Distribute extracellularly, do not penetrate brain/ CSF Act by interfering with bacterial protein synthesis. Completely eliminated unchanged in the urine by glomerular filtration. Narrow margin of safety. Bactericidal and more active at alkaline pH. Ototoxicity and nephrotoxic