TOBRAMYCIN SULFATE IN SODIUM CHLORIDE 0.9% IN PLASTIC CONTAINER
Clinical safety rating: avoid
Other nephrotoxic or ototoxic drugs increase risk of toxicity Monitor peak and trough levels to minimize risk of nephrotoxicity and ototoxicity.
Tobramycin is an aminoglycoside antibiotic that binds to the 30S ribosomal subunit, causing misreading of mRNA and inhibiting protein synthesis in susceptible bacteria.
| Metabolism | Tobramycin is primarily eliminated unchanged by the kidneys via glomerular filtration. Minimal hepatic metabolism occurs. |
| Excretion | Primarily renal (glomerular filtration) with >90% excreted unchanged in urine within 24 hours; minimal biliary/fecal (<1%). |
| Half-life | 2-3 hours in patients with normal renal function; prolonged to 24-60 hours in anuria. Half-life is directly correlated with creatinine clearance. |
| Protein binding | <30%, primarily to albumin. |
| Volume of Distribution | 0.26 L/kg in adults; higher in critically ill (0.3-0.4 L/kg). Indicates primarily extracellular fluid distribution. |
| Bioavailability | Intravenous: 100%. Not absorbed orally; inhalation: variable, systemic bioavailability <20%. |
| Onset of Action | Intravenous: rapid, within 30 minutes of infusion; peak concentrations achieved at end of infusion. |
| Duration of Action | Concentration-dependent; typically 6-8 hours with conventional dosing, longer with once-daily dosing due to post-antibiotic effect. |
| Molecular Weight | 467.53 |
3-5 mg/kg/day IV divided every 8 hours or 5-7 mg/kg IV once daily for adults with normal renal function.
| Dosage form | INJECTABLE |
| Renal impairment | CrCl 30-59 mL/min: extend interval to every 12 hours; CrCl 10-29 mL/min: every 24 hours; CrCl <10 mL/min: every 48-72 hours or per serum concentrations. |
| Liver impairment | No dose adjustment required for hepatic impairment; monitor for ototoxicity if concurrent hepatotoxicity present. |
| Pediatric use | Neonates: 4 mg/kg IV every 24-48 hours adjusted for renal function; Infants/Children: 6-7.5 mg/kg/day IV divided every 8 hours or 7.5 mg/kg IV once daily. |
| Geriatric use | Initial dose based on ideal body weight; adjust interval per renal function; monitor serum concentrations and avoid prolonged courses due to increased nephrotoxicity risk. |
| 1st trimester | Avoid unless essential; aminoglycosides cross placenta and theoretical risk of ototoxicity/nephrotoxicity; no adequate human studies. |
| 2nd trimester | Use only if clearly needed; monitor maternal renal function and drug levels; potential for fetal ototoxicity. |
| 3rd trimester | Use only for severe infections; may cause fetal eighth cranial nerve damage and nephrotoxicity; avoid prolonged use. |
Clinical note
Other nephrotoxic or ototoxic drugs increase risk of toxicity Monitor peak and trough levels to minimize risk of nephrotoxicity and ototoxicity.
| FDA category | Positive |
| Placental transfer | Crosses placenta; fetal serum levels approximately 50% of maternal levels. |
| Breastfeeding |
■ FDA Black Box Warning
Aminoglycosides can cause nephrotoxicity, ototoxicity (vestibular and auditory), and neuromuscular blockade. Risk is increased with higher doses, prolonged use, renal impairment, or concurrent use of other nephrotoxic/ototoxic drugs.
| Common Effects | Nephrotoxicity |
| Serious Effects |
Hypersensitivity to tobramycin or other aminoglycosidesMyasthenia gravis (non-depolarizing neuromuscular blockade risk)
| Precautions | Monitor renal function (serum creatinine, BUN, urine output) and auditory/vestibular function. Adjust dose based on renal function. Risk of neuromuscular blockade (caution in myasthenia gravis, parkinsonism). Avoid concurrent use of other nephrotoxic/ototoxic drugs. Use in pregnancy only if clearly needed (risk of fetalotoxicity). |
| Food/Dietary |
Loading safety data…
| Low levels in breast milk; poor oral absorption by infant; considered compatible with breastfeeding; monitor infant for diarrhea, rash, or candidiasis. |
| Lactation Rating | L2 (Safer) |
| Teratogenic Risk | Aminoglycosides cross the placenta. First trimester: limited human data, no clear structural malformations. Second and third trimesters: risk of fetal ototoxicity (eighth cranial nerve damage) and nephrotoxicity, especially with prolonged or high-dose exposure. Avoid unless essential. |
| Fetal Monitoring | Maternal: serial audiometry and renal function tests (serum creatinine, BUN); serum drug levels (peak and trough); monitor for vestibular toxicity. Fetal: ultrasound for growth and amniotic fluid volume if prolonged use. |
| Fertility Effects | No known adverse effects on fertility in humans. Animal studies show no impairment. |
| No significant food interactions. Maintain adequate hydration. Avoid excessive salt intake if fluid overload is a concern. |
| Clinical Pearls | Monitor peak and trough levels to ensure therapeutic efficacy and avoid nephrotoxicity/ototoxicity. Adjust dosing based on renal function. Use with caution in patients with neuromuscular disorders due to potential for neuromuscular blockade. Inhaled tobramycin is preferred for Pseudomonas aeruginosa in cystic fibrosis; IV formulation is for systemic infections. Check for cross-sensitivity with other aminoglycosides. |
| Patient Advice | Drink plenty of fluids unless instructed otherwise to help prevent kidney problems. · Report any hearing loss, ringing in the ears, dizziness, or changes in urination immediately. · Take the full course of antibiotics as prescribed, even if you feel better. · Do not use any other medications, including over-the-counter drugs, without consulting your doctor. · Tell your doctor if you have kidney disease, muscle disorders, or are pregnant/breastfeeding. |