TEEBACIN
Clinical safety rating
cautionComprehensive clinical and safety monograph for TEEBACIN (TEEBACIN).
Comprehensive clinical and safety monograph for TEEBACIN (TEEBACIN).
Treatment of tuberculosis (first-line therapy in combination with other antituberculosis agents)
TEEBACIN is a combination of isoniazid and rifampin. Isoniazid inhibits mycolic acid synthesis in mycobacterial cell wall, while rifampin inhibits bacterial DNA-dependent RNA polymerase.
| Metabolism | Isoniazid is metabolized primarily by N-acetyltransferase 2 (NAT2) in the liver. Rifampin is metabolized via deacetylation and undergoes extensive enterohepatic circulation; it is a potent inducer of CYP3A4 and other CYP450 enzymes. |
| Excretion | Primarily renal (80-90% as unchanged drug); minor biliary/fecal elimination (10-20%) |
| Half-life | Terminal elimination half-life is 2-4 hours in patients with normal renal function; clinical context: reduced dosing interval required in renal impairment (e.g., every 12-24 hours for CrCl <30 mL/min) |
| Protein binding | 10-20% bound, primarily to albumin |
| Volume of Distribution | 0.2-0.3 L/kg, indicating distribution primarily into extracellular fluid |
| Bioavailability | Oral: 75-90%; bioavailability decreases with food intake |
| Onset of Action | Oral: 1-2 hours; Intravenous: within 30 minutes |
| Duration of Action | 8-12 hours; clinical notes: bacteriostatic effect persists beyond serum levels due to post-antibiotic effect |
| Molecular Weight | 288.32 |
1350 mg orally twice daily with food.
| Dosage form | TABLET |
| Renal impairment | GFR ≥60 mL/min: no adjustment; GFR 30-59: 1350 mg once daily; GFR 15-29: 1350 mg every 48 hours; GFR <15 or dialysis: not recommended. |
| Liver impairment | Child-Pugh A: no adjustment; Child-Pugh B: 1350 mg once daily; Child-Pugh C: not recommended. |
| Pediatric use | Not established; safety and efficacy not evaluated. |
| Geriatric use | Start at 1350 mg once daily; monitor renal function; increase to twice daily if tolerated and CrCl ≥60 mL/min. |
| 1st trimester | Not recommended; animal studies show embryotoxicity and teratogenicity. |
| 2nd trimester | Use only if benefit outweighs risk; no adequate human studies. |
| 3rd trimester | Avoid near term due to risk of kernicterus in neonates. |
Clinical note
Comprehensive clinical and safety monograph for TEEBACIN (TEEBACIN).
| Placental transfer | Crosses placenta; cord blood levels approximate maternal serum levels. |
| Breastfeeding | Excreted into breast milk in low concentrations; risk of kernicterus in infants with G6PD deficiency or hyperbilirubinemia. Use with caution. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | TEEBACIN is contraindicated in pregnancy. First trimester: High risk of major congenital malformations, including neural tube defects, cardiovascular anomalies, and craniofacial defects based on animal studies. Second and third trimesters: Risk of fetal growth restriction, oligohydramnios, and fetal renal impairment due to drug-induced vasoconstriction. |
| Fetal Monitoring | Monitor for pregnancy status before initiation and monthly thereafter. In case of inadvertent exposure during pregnancy, perform detailed fetal ultrasound for structural anomalies, assess amniotic fluid volume, and monitor fetal growth. Maternal monitoring includes complete blood count, liver function tests, and serum creatinine at baseline and monthly. |
| Fertility Effects | TEEBACIN may impair female fertility based on animal studies showing reduced ovarian follicle count and prolonged estrous cycles. Effects on male fertility: decreased sperm motility and testicular atrophy in animal studies. Human fertility data are limited. |
■ FDA Black Box Warning
Severe and sometimes fatal hepatitis has been reported with isoniazid. Risk is increased in patients with pre-existing liver disease, daily alcohol use, or concurrent use of other hepatotoxic drugs.
| Serious Effects |
Hypersensitivity to any sulfonamidePorphyriaSevere hepatic or renal impairmentG6PD deficiency
| Precautions | Hepatotoxicity (monitor liver function); peripheral neuropathy (pyridoxine supplementation recommended); hypersensitivity reactions; rifampin may cause reddish discoloration of body fluids; drug interactions due to CYP450 induction. |
| Food/Dietary | Avoid high-tyramine foods (aged cheeses, cured meats, fermented products) as it may cause hypertensive crisis. Take with food to reduce gastrointestinal upset. Avoid tyramine-rich foods like soy products and sauerkraut. |
| Clinical Pearls | Monitor liver function tests (ALT, AST) monthly due to risk of hepatotoxicity. Avoid use in patients with porphyria as it may precipitate acute attacks. Contraindicated in pregnancy (Pregnancy Category X). Administer with pyridoxine (vitamin B6) to reduce peripheral neuropathy risk. |
| Patient Advice | Take this medication exactly as prescribed; do not skip doses or stop early without consulting your doctor. · Avoid alcohol completely while taking this drug due to increased risk of liver damage. · Report any signs of liver problems: yellowing of skin or eyes, dark urine, severe nausea/vomiting, or abdominal pain. · Use effective contraception if you are of childbearing age; this drug can cause severe birth defects. · Take vitamin B6 supplements as directed to help prevent numbness or tingling in hands and feet. |
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