TAO
Clinical safety rating: caution
Comprehensive clinical and safety monograph for TAO (TAO).
Troleandomycin (TAO) is a macrolide antibiotic that inhibits bacterial protein synthesis by binding to the 50S ribosomal subunit, preventing peptide chain elongation.
| Metabolism | Primarily hepatic via cytochrome P450 3A4 (CYP3A4); inhibits CYP3A4, leading to drug interactions. |
| Excretion | Primarily hepatic metabolism with <10% excreted unchanged in urine; approximately 30% excreted in feces via bile. |
| Half-life | Terminal elimination half-life of 12-24 hours in adults; may be prolonged in hepatic impairment (up to 40-60 hours) and in neonates (2-5 days). |
| Protein binding | 92-94% primarily to albumin and α1-acid glycoprotein. |
| Volume of Distribution | 0.5-0.8 L/kg, indicating moderate tissue distribution. |
| Bioavailability | Oral: 30-40% (variable due to first-pass metabolism); intramuscular: 70-80%. |
| Onset of Action | Oral: 1-2 hours; intravenous: within 30 minutes; topical: several hours to days for effect. |
| Duration of Action | Oral: 6-12 hours; IV: 8-12 hours; duration may be extended in hepatic dysfunction. |
| Molecular Weight | 180.16 |
250-500 mg orally every 6 hours or 500 mg intravenously every 6 hours. For severe infections, up to 500 mg every 6 hours IV.
| Dosage form | SUSPENSION |
| Renal impairment | CrCl 10-50 mL/min: administer 250 mg every 6-8 hours or 500 mg every 12 hours. CrCl <10 mL/min: 250 mg every 12 hours or 500 mg every 24 hours. |
| Liver impairment | Child-Pugh Class A: no adjustment. Class B: reduce dose by 50% or extend interval to every 8-12 hours. Class C: avoid use or reduce dose by 75% with monitoring. |
| Pediatric use | Neonates: 20-30 mg/kg/day divided every 12 hours. Infants/children: 40-50 mg/kg/day orally divided every 6 hours or 30-40 mg/kg/day IV divided every 6 hours. |
| Geriatric use | Initiate at lower end of dosing range (250 mg every 6 hours) and adjust based on renal function; monitor for QT prolongation and electrolyte disturbances. |
| 1st trimester | Avoid; associated with congenital anomalies including cardiac defects and neural tube defects. |
| 2nd trimester | Avoid; risk of fetal growth restriction and preterm birth. |
| 3rd trimester | Avoid; risk of neonatal hemorrhage and premature closure of ductus arteriosus. |
Clinical note
Comprehensive clinical and safety monograph for TAO (TAO).
| Placental transfer | Readily crosses placenta; achieves fetal serum concentrations similar to maternal levels. |
| Breastfeeding | Excreted into breast milk in small amounts; potential for adverse effects in infants such as bleeding and renal impairment; use only if benefit outweighs risk. |
| Lactation Rating |
■ FDA Black Box Warning
None
| Serious Effects |
Active peptic ulcer diseaseHemophilia or other bleeding disordersSevere renal failure (CrCl <30 mL/min)History of hypersensitivity to TAO (triamcinolone acetonide ophthalmic)Untreated infection
| Precautions | Hepatotoxicity: elevated liver enzymes, jaundice; discontinue if signs of liver injury, QT prolongation: risk of cardiac arrhythmias, especially with other QT-prolonging drugs, Drug interactions: potent CYP3A4 inhibitor; avoid with certain statins, ergot alkaloids, and other CYP3A4 substrates |
| Food/Dietary | Avoid grapefruit and grapefruit juice as they may increase toxicity. Take with food to reduce gastrointestinal irritation. |
Loading safety data…
| L3 (Moderately Safe) |
| Teratogenic Risk | Troleandomycin (TAO) is a macrolide antibiotic. Limited human data; animal studies show no teratogenicity. FDA Category C. First trimester: theoretical risk, avoid unless essential. Second and third trimesters: generally considered safe, but use only if clearly needed due to potential maternal hepatotoxicity. |
| Fetal Monitoring | Monitor liver function tests (ALT, AST, bilirubin) in pregnant women due to risk of cholestatic hepatitis. Fetal ultrasound may be considered for prolonged therapy. |
| Fertility Effects | No known adverse effects on fertility in humans or animal studies. |
| Clinical Pearls |
| Troleandomycin (TAO) is a macrolide antibiotic rarely used due to hepatotoxicity. It inhibits CYP3A4, causing significant drug interactions (e.g., with theophylline, carbamazepine, warfarin). Monitor liver function tests (LFTs) and drug levels of narrow therapeutic index drugs. Contraindicated in hepatic impairment. |
| Patient Advice | Take exactly as prescribed; do not skip doses. · May cause stomach upset; take with food. · Report jaundice, dark urine, or abdominal pain immediately. · Avoid alcohol while taking this medication. · Inform all healthcare providers of use due to drug interactions. |