Generic name: Rifapentine.

Priftin is an antibiotic. It is used to prevent bacteria from multiplying and growing.

Quick Facts About Priftin


Used to treat pulmonary tuberculosis (TB). Must be used in combination with at least one other anti-TB drug.

Priftin Dosage

Take exactly as prescribed, in combination with up to 3 other prescribed medications. Must not miss any doses in order to keep infection from returning, especially in the first intensive phase of treatment. Take with food if you experience nausea.

  • Usual adult dose: first phase — 4 tablets (600 milligrams) twice per week, with no fewer than 3 days (72 hours) between doses for 2 months. Second phase — 4 tablets (600 milligrams) once per week for 4 months. Doctor will recommend alternative treatment if TB test is still positive after full Priftin treatment.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: must not miss dose. Contact doctor if dose is missed.

Priftin Side Effects

Overdose symptoms:

none reported; however, if you suspect an overdose, immediately seek medical attention.

More common side effects: excess uric acid in blood, high blood sugar levels, increased liver function, low white blood cell count, red-orange discoloration of body fluids (urine, sweat, spit, tears) or tissues (skin, teeth, tongue).

Less common Priftin side effects: anorexia or appetite loss, anemia, blood, pus, or protein in urine, itching, joint pain, low blood iron levels, nausea, pain, rash, upset stomach, urinary casts, vomiting. Rare side effects: acne, coughing up blood, diarrhea, dizziness, headache, high blood platelet levels, high blood pressure


Combining Priftin with protease inhibitors such as Invirase, Norvir, and Viracept may cause dangerous side effects.

Do not combine Priftin with:

anticonvulsants such as phenytoin (Dilantin); anti-arrhythmics such as disopyramide (Norpace), mexiletine (Mexitil) quinidine (Quinalan), and tocainide (Tonocard); antibiotics such as clarithromycin (Biaxin), and doxycycline (Doryx, Monodox, and Vibramycin); antifungai such as itraconazole (Sporanox) and ketoconazole (Nizoral); barbiturates; benzodiazepines such as Valium; calcium channel blockers such as diltiazer (Cardizem), nifedipine (Procardia), and verapam (Calan and Isoptin); corticosteroids; cardiac glycoside preparations: dofibrate (Atromid-S); fluoroquinolones such as ciprofloxacin (Cipro); haloperidol (Haldol); immunosuppressants such as cyclosporine (Sandimmune) and tacrolimus (Prograf); levothyroxine; narcotic analgesics such as methadone; oral or implanted contraceptives; progestins; quinine (Quindan); reverse transcriptase inhibitors such as delavirdine (Rescriptor) and zidovudine (Retrovir); sildenafil; sulfonylureas; theophylline (Theo-Dur); tricyclic antidepressants such as amitriptyline (Elavil) and nortriptyline (Aventyl); warfarin (Coumadin).

No known food/other substance interactions.

Special Cautions

Blood-clotting problems may develop in third trimester of f pregnancy. If pregnant, planning to become pregnant, or breastfeeding, inform your doctor immediately.

No special precautions apply to seniors.

Not generally prescribed for children.

  • May produce a reddish coloration of the urine, sweat, sputum, and tears; contact lenses may be permanently stained.
  • Use with caution if you have a history of liver problems or abnormal liver test results. If prescribed, doctor will monitor closely.
  • Contact your doctor immediately if you experience fever, loss of appetite, malaise, nausea and vomiting, darkened urine, yellowish discoloration of the skin and eyes, and pain or swelling of the joints.
  • If taking oral or other hormonal contraceptives, use alternate birth control device.
  • If you experience severe or constant diarrhea, stop medication immediately and contact your doctor.

Note: provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Priftin side effects, please contact your healthcare provider