Gentamicin
Mechanism :
It inhibits essential protein synthesis in the bacterial cell required for survival. It is used in the treatment of severe gram-negative infections and also has some activity against coagulase positive staphylococci.
Indication :
- Gram negative infections
- It is also used in many creams and ointments for topical application in skin infections and as ophthalmic solution for eye infections.
Contraindications :
Hypersensitivity to gentamicin and myasthenia gravis is a contraindication to its use. Patients should be well hydrated during therapy, and renal function should be monitored. Dose adjustment is required in impaired renal function.
Dosing :
IV:
<8 days of life:
2.5 mg/kg IV/IM every 12 hours.
>8 days-2 months:
2.5 mg/kg IV/IM every 8 hours.
>2 months:
7.5 mg IV/IM once daily.
Adverse Effect :
Vestibular, auditory, nephrotoxicity and neuromuscular blockade.
Interaction :
Vancomycin, Cephalosporin, Cyclosporine, Furosemide, Cisplatin, Amphotericin: Increases chances of ototoxicity and nephrotoxicity.
Non-Depolarising Muscle Relaxants: Enhances effect.
Neostigmine, Pyridostigmine: Antagonises effect.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 30-70 | 3–5 mg/kg daily and monitor levels |
| 10-30 | 2–3 mg/kg daily and monitor levels |
| 5-10 | 2 mg/kg every 48–72 hours according to levels |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Dialysed. CAPD clearance is about 3 mL/min. Dose as in GFR=5–10 mL/min. Monitor levels |
| HD | Dialysed. Dose as in GFR=5– 10 mL/min. Give after dialysis |
| HDF/High flux | Dialysed. Dose as in GFR=5– 10 mL/min. Give after dialysis |
| CAV/VVHD | Dialysed. Dose in GFR= 30– 70 mL/min according to severity of infection, and measure levels |
Hepatic Dose :
No dosage adjustments are needed.