BRISTACYCLINE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for BRISTACYCLINE (BRISTACYCLINE).
BRISTACYCLINE is a tetracycline antibiotic that reversibly binds to the 30S ribosomal subunit, inhibiting bacterial protein synthesis by blocking the attachment of aminoacyl-tRNA to the mRNA-ribosome complex.
| Metabolism | Hepatic metabolism is minimal; primarily excreted unchanged in urine and feces via biliary secretion. |
| Excretion | Renal (40-60% unchanged), fecal (20-30%, primarily as inactive metabolites). Biliary excretion contributes minimally (<5%). |
| Half-life | 6-12 hours (terminal). In renal impairment, half-life extends up to 24-48 hours; dose adjustment required for CrCl <30 mL/min. |
| Protein binding | 50-60% (primarily albumin and some beta-globulins). |
| Volume of Distribution | 1.5-2.0 L/kg (indicates extensive tissue penetration, including bone and teeth). |
| Bioavailability | Oral: 60-80% (reduced by food, dairy, antacids, iron, calcium). IV: 100%. |
| Onset of Action | Oral: 1-2 hours; IV: immediate (peak concentrations achieved by end of infusion). |
| Duration of Action | 12-24 hours (bacteriostatic levels). Clinical effect may persist for 2-3 days after last dose due to tissue accumulation. |
250 mg orally every 6 hours for 7-14 days.
| Dosage form | CAPSULE |
| Renal impairment | GFR <30 mL/min: 250 mg every 12 hours. GFR 30-50 mL/min: no adjustment. GFR <10 mL/min: contraindicated. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce dose by 50%. Child-Pugh C: contraindicated. |
| Pediatric use | For children >8 years: 25-50 mg/kg/day orally divided every 6 hours, maximum 2 g/day. For children <8 years: contraindicated due to tooth discoloration. |
| Geriatric use | No specific dose adjustment required, but monitor renal function and adjust based on GFR; increased risk of esophagitis, ensure adequate fluid intake. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for BRISTACYCLINE (BRISTACYCLINE).
| Breastfeeding | Excreted in breast milk; M/P ratio ~0.6. Low relative infant dose (<10%). Theoretical risk of dental staining and bone growth suppression in nursing infants. AAP considers compatible with breastfeeding. Caution in prolonged therapy; monitor infant for gastrointestinal disturbances. |
| Teratogenic Risk | First trimester: Associated with neural tube defects (NTDs) and cardiovascular anomalies (OR 1.5-2.0 for major malformations). Second/third trimesters: Risk of fetal bone growth inhibition, dental enamel hypoplasia, and permanent tooth discoloration. Tetracycline accumulation in fetal bones and teeth. Contraindicated after 15 weeks gestation due to hepatotoxicity risk in pregnant patients. |
■ FDA Black Box Warning
No FDA black box warning is listed for BRISTACYCLINE.
| Serious Effects |
Hypersensitivity to tetracyclines; severe hepatic dysfunction; pregnancy; breastfeeding; children under 8 years.
| Precautions | Photosensitivity reactions; tooth discoloration (children under 8 years); impaired bone growth; hepatotoxicity (rare); pseudotumor cerebri (benign intracranial hypertension); use with caution in renal impairment. |
| Food/Dietary | Avoid dairy products, calcium-fortified foods, antacids, iron, zinc, and magnesium supplements within 2 hours of administration. Food, especially dairy, significantly reduces absorption. Take on empty stomach. |
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| Fetal Monitoring | Maternal: Liver function tests (bilirubin, AST/ALT), renal function (serum creatinine, BUN), and blood counts at baseline and monthly. Fetal: Ultrasound monitoring for fetal growth restriction (starting at 24 weeks if used after 15 weeks). Newborn: Evaluate for hyperbilirubinemia and monitor teeth for discoloration postnatally. |
| Fertility Effects | No known direct effect on fertility in human studies. High doses in animal models cause reversible sperm motility reduction and ovarian follicular degeneration. No established impact on ovulation or spermatogenesis at therapeutic doses in humans. |
| Clinical Pearls |
| Bristacycline is a tetracycline antibiotic. Avoid in children <8 years and pregnancy due to tooth discoloration and bone growth inhibition. Use with caution in renal impairment; adjust dose. Photosensitivity is common; advise sun protection. Monitor for superinfection, especially C. difficile diarrhea. |
| Patient Advice | Take on an empty stomach (1 hour before or 2 hours after meals) with a full glass of water. · Avoid dairy products, antacids, iron supplements, and calcium-rich foods within 2 hours of dosing. · Finish the entire prescription even if symptoms improve. · Use sunscreen and wear protective clothing; avoid sunbeds. · Report persistent diarrhea, vaginal itching, or skin rash to your doctor. · Do not use during pregnancy or breastfeeding; use effective contraception. · Store at room temperature away from light and moisture. |