OPTOMYCIN
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OPTOMYCIN (OPTOMYCIN).
Optomycin is a semi-synthetic glycopeptide antibiotic that inhibits bacterial cell wall synthesis by binding to the D-alanyl-D-alanine terminus of the peptidoglycan precursor, preventing transpeptidation and cross-linking.
| Metabolism | Optomycin is not significantly metabolized. It is primarily eliminated unchanged in the urine via glomerular filtration. Does not undergo hepatic metabolism; no known CYP450 interactions. |
| Excretion | Renal: 75-90% unchanged; biliary: 5-10%; fecal: <5%. |
| Half-life | 3-5 hours (terminal half-life); prolonged to 10-20 hours in renal impairment. |
| Protein binding | 30-40% bound to serum albumin. |
| Volume of Distribution | 0.5-0.8 L/kg; indicates distribution into extracellular fluid. |
| Bioavailability | IM: 90-100%; Oral: <5% (not therapeutically relevant). |
| Onset of Action | IV: 30-60 min; IM: 1-2 hours; Oral: not applicable (poor absorption). |
| Duration of Action | 6-8 hours for IV/IM; bacteriostatic effects persist up to 12 hours post-peak. |
| Molecular Weight | 585.6 |
1.5 mg/kg IV every 8 hours; alternatively, 5-7 mg/kg IV daily.
| Dosage form | SOLUTION/DROPS |
| Renal impairment | CrCl 30-59 mL/min: 1.5 mg/kg IV every 12-24 hours; CrCl 10-29 mL/min: 1.5 mg/kg IV every 24-48 hours; CrCl <10 mL/min: 1.5 mg/kg IV every 48-72 hours. Consider therapeutic drug monitoring. |
| Liver impairment | No dose adjustment required for Child-Pugh A, B, or C. Use with caution in severe hepatic impairment due to potential nephrotoxicity risk. |
| Pediatric use | Neonates: 4 mg/kg IV every 12 hours (postnatal age <7 days) or every 8 hours (7-28 days). Infants and children: 2.5 mg/kg IV every 8 hours. Maximum single dose 100 mg. |
| Geriatric use | Start at lower end of dosing range (e.g., 1-1.5 mg/kg IV every 12-24 hours) based on renal function. Monitor serum creatinine and drug levels closely. |
| 1st trimester | Avoid; known to cause fetal harm (ototoxicity and nephrotoxicity) in animal studies; no adequate human data. |
| 2nd trimester | Avoid; potential for fetal ototoxicity and nephrotoxicity; only if benefit outweighs risk for severe infections. |
| 3rd trimester | Avoid; risk of fetal ototoxicity and nephrotoxicity; consider alternative therapy. |
Clinical note
Comprehensive clinical and safety monograph for OPTOMYCIN (OPTOMYCIN).
| Placental transfer | Crosses placenta; achieves fetal serum concentrations approximately 30-50% of maternal levels. |
| Breastfeeding | Excreted into breast milk in low concentrations; potential for infant gut flora alteration and sensitization; use only if clearly needed. |
| Lactation Rating |
■ FDA Black Box Warning
WARNING: NEPHROTOXICITY AND OTOTOXICITY - Optomycin can cause acute kidney injury and irreversible sensorineural hearing loss. Monitor renal function and auditory function before and during therapy. Avoid concurrent use of other nephrotoxic or ototoxic agents.
| Serious Effects |
Hypersensitivity to optomycin or any aminoglycosideMyasthenia gravisPregnancy (unless no safer alternative)
| Precautions | Monitor renal function (serum creatinine, BUN, urinalysis) at baseline and regularly during therapy; adjust dose based on creatinine clearance. Perform audiometric testing at baseline and weekly during prolonged therapy. Risk of ototoxicity increased with high trough levels (>20 mg/L). Use with caution in patients with pre-existing renal impairment, hearing loss, or those receiving concomitant nephrotoxic agents. May cause red man syndrome (histamine release) if infused too rapidly; premedicate with antihistamines if needed. Neurotoxicity including optic neuropathy and peripheral neuropathy reported. Monitor for Clostridium difficile-associated diarrhea. |
| Food/Dietary |
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| L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: No adequate human data; animal studies show no teratogenic effects at clinically relevant doses. Second trimester: Risk of fetal ototoxicity if maternal aminoglycoside levels exceed therapeutic range. Third trimester: Potential for fetal renal and auditory toxicity; avoid use unless essential. |
| Fetal Monitoring | Monitor maternal serum drug levels (peak and trough); assess renal function (serum creatinine, BUN); monitor fetal growth and amniotic fluid volume via ultrasound; perform neonatal auditory screening after delivery. |
| Fertility Effects | No known negative impact on fertility in animal studies. Human data insufficient. |
| Dairy products, calcium-fortified foods, iron-rich foods, and antacids containing aluminum, calcium, or magnesium should be avoided within 2-3 hours of dosing. Separate intake of multivitamins or supplements containing zinc or iron by at least 2 hours. |
| Clinical Pearls | Optomycin is a broad-spectrum tetracycline antibiotic. Administer on an empty stomach (1 hour before or 2 hours after meals) to enhance absorption. Avoid concurrent use with antacids, dairy products, iron, calcium, magnesium, or bismuth subsalicylate, as they chelate and reduce absorption. Monitor for photosensitivity reactions; advise sun protection. Contraindicated in pregnancy (category D) and children under 8 years due to bone and tooth discoloration. Use with caution in hepatic impairment. |
| Patient Advice | Take on an empty stomach with a full glass of water. · Avoid dairy, antacids, iron, or calcium supplements within 2-3 hours of dose. · Use sunscreen and protective clothing to prevent sunburn. · Finish all medication even if symptoms improve. · Inform your doctor if you are pregnant or breastfeeding. · Report severe diarrhea, rash, or headache immediately. |