Rifapentine
PRIFTIN
What it isLong-acting RNA-polymerase-inhibiting rifamycin; latent and active tuberculosis.
Why this oneIts prolonged activity enables short, intermittent latent-TB regimens that are easier to complete than daily isoniazid.
What limits itA potent enzyme inducer as for the class. Orange body fluids and flu-like reactions complicate intermittent dosing.
FDA-approved for
- tuberculosis (1998)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Active pulmonary TB — initial phase (2 mo), w/ other anti-TB drugs | adult | 600 mg twice weekly | 600 mg twice weekly | 600 mg/dose |
| Active pulmonary TB — continuation phase (4 mo), w/ isoniazid | adult | 600 mg once weekly | 600 mg once weekly | 600 mg/dose |
| Latent TB infection, w/ isoniazid x12 wk | adult & peds ≥12 yr | weight-based 300-900 mg once weekly | weight-based 300-900 mg once weekly | 900 mg/week |
| Latent TB infection, w/ isoniazid x12 wk | pediatric 2-11 yr | weight-based 300-900 mg once weekly | weight-based 300-900 mg once weekly | 900 mg/week |
Renal Undefined
Hepatic Undefined (use only if necessary with monitoring in liver disease; no dose adjustment stated)
Active TB initial phase: no less than 72 hours (3 days) between the twice-weekly doses
Instructions
- Take with food
- Tablets may be crushed and added to a small amount of semi-solid food, consumed immediately
- Always used in combination with other anti-TB drugs
Cautions
- Hepatotoxicity; monitor transaminases in at-risk patients, discontinue if liver injury
- Hypersensitivity reactions incl. anaphylaxis
- Severe cutaneous adverse reactions (SJS, DRESS)
- Do not use once-weekly continuation regimen with isoniazid in HIV-infected patients (higher failure/relapse)
- Paradoxical drug reactions
- Potent CYP450 induction (reduces protease inhibitors, hormonal contraceptives, etc.)
- Red-orange discoloration; may permanently stain contact lenses/dentures
- C. difficile-associated diarrhea
- Avoid in porphyria
Adverse reactions
- Anemia, lymphopenia, neutropenia
- Hemoptysis, cough
- Increased ALT/AST
- Rash
- Hyperuricemia
- LTBI: hypersensitivity reaction
Pregnancy Based on animal data, may cause fetal harm; late-pregnancy use may cause maternal/neonatal bleeding (monitor PT; vitamin K may be indicated)
Lactation May discolor breast milk; monitor breastfed infant for signs of hepatotoxicity
NO BOXED WARNINGS
Principal riskA potent enzyme inducer; flu-like reactions
Cost, est. cash$300–$2,500/month
Generic entryApproved, not yet marketed
Classes and tags
Clinical profile
Legacy pregnancy categoryUnknown / historical label unavailable
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.
Mechanism of action: Rifapentine ballicule
