Gentamicin

MOA:

Gentamicin, an aminoglycoside, binds to the prokaryotic ribosome, inhibiting protein synthesis in susceptible bacteria.  It is bactericidal in vitro against Gram-positive and Gram-negative bacteria.

Drug Label Information | Brands:

Brands of Gentamicin in Kenya

Caregenta-80 , Careplus ltd
Dawagenta, Dawa limited
Genacyn, Square Pharmaceuticals Ltd.
Gentagen, Shanghai Agen International Trade Co.ltd
Gentamed , Medisel Kenya Limited
Gentamycin, Fresenius Kabi Manufacturing SA (Pty) Limited
Gentamycin, Elys Chemicals Industries Ltd.
Gentamycin , United Pharma (K) Ltd
Intamycin , Radiance Pharmaceuticals Ltd
Mycin, Neon Laboratories Ltd.

Gentamicin sulfate, a water-soluble antibiotic of the aminoglycoside group, is derived by the growth of Micromonospora purpurea, an actinomycete.

Mechanism of Resistance

Bacterial resistance to gentamicin is generally developed slowly. Bacteria resistant to one aminoglycoside may be resistant to one or more other aminoglycosides. The following bacteria are usually resistant to the
fcillin or oxacillin.

The combined effect of gentamicin and carbenicillin is synergistic for many strains of Pseudomonas aeruginosa. In vitro synergism against other Gram-negative organisms has been shown with combinations of gentamicin and cephalosporins.

Gentamicin may be active against clinical isolates of bacteria resistant to other aminoglycosides.

INDICATIONS

Gentamicin , is indicated in the treatment of serious infections caused by susceptible strains of the following microorganisms: Pseudomonas aeruginosa, Proteus species (indole-positive and indole-negative), Escherichia coli, Klebsiella-Enterobacter-Serratia species, Citrobacter species and Staphylococcus species (coagulase-positive and coagulase-negative).

CONTRAINDICATIONS

Hypersensitivity to gentamicin is a contraindication to its use. A history of hypersensitivity or serious toxic reactions to other aminoglycosides may contraindicate use of gentamicin because of the known cross-sensitivity of patients to drugs in this class.

ADVERSE DRUG REACTIONS

Nephrotoxicity

Adverse renal effects, as demonstrated by the presence of casts, cells or protein in the urine or by rising BUN, NPN, serum creatinine or oliguria, have been reported. They occur more frequently in patients with a history of renal impairment (especially if dialysis is required) and in patients treated for longer periods or with larger doses than recommended.

Neurotoxicity

Serious adverse effects on both vestibular and auditory branches of the eighth nerve have been reported, primarily in patients with renal impairment (especially if hemodialysis is required) and in patients on high doses and/or prolonged therapy. Symptoms include dizziness, vertigo, tinnitus, roaring in the ears and also hearing loss, which, as with the other aminoglycosides, may be irreversible. Hearing loss is usually manifested initially by diminution of high-tone acuity. Other factors which may increase the risk of toxicity include excessive dosage, dehydration and previous exposure to other ototoxic drugs.

Peripheral neuropathy or encephalopathy, including numbness, skin tingling, muscle twitching, convulsions and a myasthenia gravis-like syndrome have been reported.

DRUG INTERACTIONS:

Concurrent and/or sequential systemic or topical use of other potentially neurotoxic and/or nephrotoxic drugs, such as cisplatin, cephaloridine, kanamycin, amikacin, neomycin, polymyxin B, colistin, paromomycin, streptomycin, tobramycin, vancomycin and viomycin, should be avoided. Other factors which may increase patient risk of toxicity are advanced age and dehydration.

The concurrent use of gentamicin with potent diuretics, such as ethacrynic acid or furosemide, should be avoided, since certain diuretics by themselves may cause ototoxicity. In addition, when administered intravenously, diuretics may enhance aminoglycoside toxicity by altering the antibiotic concentration in serum and tissue.