Tobramycin

Tobramycin In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Aminoglycosides inhibit bacterial protein synthesis; their mechanism of killing is concentration-dependent, leading to a marked post-antibiotic effect, allowing pulse-dosing regimens which may limit toxicity.

Uses of Tobramycin

• Treatment of Gram-negative infections.
• Less active against most Gram-negative organisms compared to gentamicin, but more effective against Pseudomonas aeruginosa.
• Ineffective against obligate anaerobic bacteria and at sites of low oxygen tension like abscesses.
• More pharmacokinetic research is needed, especially in cats who may be more sensitive to toxicity.
• Dosing guidelines provided are for general reference and should be adjusted based on clinical response.
• Potential side effects include nephrotoxicity and ototoxicity.
• Cellular casts in urine sediment are an early sign of impending nephrotoxicity, but their absence does not guarantee safety.
• Monitor renal function during use; serum creatinine levels may rise later, indicating fatal acute renal failure.
• Administer intravenous doses slowly; reserve use in geriatric animals or those with reduced renal function for essential cases only.

Dose of Tobramycin in Dogs and Cats

Dogs and Cats:

• Parenteral: 4–6 mg/kg i.v., s.c., i.m. q24h.
• For severe infections (including sepsis), doses as high as 12 mg/kg/day have been advocated, but should be used with caution given potential adverse effects.

Side Effects of Tobramycin in Dogs and Cats

• Tobramycin is considered to be less nephrotoxic than gentamicin.

Contraindications of Tobramycin in Dogs and Cats

• Do not use ophthalmic products where corneal ulceration is present.

Some Notes:

• Avoid concurrent use of other nephrotoxic, ototoxic, or neurotoxic agents such as amphotericin B and furosemide.
• Increase monitoring and adjust dosages when these drugs must be used together.
• Aminoglycosides may be chemically inactivated by beta-lactam antibiotics (e.g., penicillins, cephalosporins) or heparin when mixed in vitro.
• Non-depolarizing muscle relaxants (e.g., pancuronium) effects may be enhanced by aminoglycosides.
• Synergism may occur when aminoglycosides are used with penicillins or cephalosporins.