RIFAPENTINE
| RIFAPENTINe (rif'a-pen-teen) Priftin Classifications: antibiotic; antituberculosis agent; Therapeutic: antibiotic; antituberculosis agent Prototype: Rifampin Pregnancy Category: C |
Availability
150 mg tablets
Action
Rifamycin derivative similar to rifampin. Inhibits DNA-dependent RNA polymerase activity in susceptible bacterial cells, thereby suppressing RNA synthesis. Inhibits the growth of Mycobacterium tuberculosis.
Therapeutic Effect
Effective against Mycobacterium tuberculosis, indicated by improvement in clinical S&S (e.g., fever, cough, pleuritic pain, fatigue) and on chest x-ray.
Uses
Pulmonary tuberculosis in conjunction with at least one other antitubercular agent.
Contraindications
Hypersensitivity to any rifamycins (e.g., rifampin, rifabutin, rifapentine); porphyria; pregnancy (category C); lactation.
Cautious Use
Patients with abnormal liver function tests or hepatic disease; older adults; HIV disease or concurrent use of protease inhibitors. Safe use in children <12 y not established.
Route & Dosage
| Tuberculosis: Short-Course Therapy Adult: PO 600 mg twice weekly (at least 72 h apart) x 2 mo, then 600 mg once weekly x 4 mo |
Administration
Oral- Give with an interval of NO LESS than 72 h between doses.
- Give with food to minimize GI upset.
- Store at 15°–30° C (59°–86° F) in a tightly closed container and protect from excess moisture.
Adverse Effects (≥1%)
CNS: Headache, dizziness. CV: Hypertension. GI: Increased liver function tests (ALT, AST), anorexia, nausea, vomiting, dyspepsia, diarrhea. GU: Hyperuricemia, pyuria, proteinuria, hematuria, urinary casts. Hematologic: Neutropenia, lymphopenia, anemia, leukopenia, thrombocytosis. Respiratory: Hemoptysis. Skin: Rash, pruritus, acne. Body as a Whole: Arthralgia, pain.Interactions
Drug: Decreased levels of indinavir and possibly other protease inhibitors; increased metabolism and decreased activity of oral contraceptives, phenytoin, disopyramide, mexiletine, quinidine, tocainide, warfarin, fluconazole, itraconazole, ketoconazole, diazepam, beta blockers, calcium channel blockers, corticosteroids, haloperidol, sulfonylureas, cyclosporine, tacrolimus, levothyroxine, narcotic analgesics, quinine, reverse transcriptase inhibitors, tricyclic antidepressants, sildenafil, theophylline.Pharmacokinetics
Absorption: Approximately 70% absorbed. Peak: 5–6 h. Distribution: 97.7% protein bound. Metabolism: Hydrolyzed by esterase enzyme to active metabolite in liver; inducer of cytochromes P450 3A4 and 2C8/9. Elimination: 70% in feces, 17% in urine. Half-Life: 13.3 h.Nursing Implications
Assessment & Drug Effects
- Lab tests: Sputum smear and culture, CBC, baseline liver functions (especially serum transaminases) to rule out preexisting hepatic disease and serum creatinine and BUN.
- Monitor carefully for S&S of toxicity with concurrent use of oral anticoagulants, digitalis preparations, or anticonvulsants.
Patient & Family Education
- Follow strict adherence to the prescribed dosing schedule to prevent emergence of resistant strains of tuberculosis.
- Be aware that food may be useful in preventing GI upset.
- Report immediately any of the following to the physician: fever, weakness, nausea or vomiting, loss of appetite, dark urine or yellowing of eyes or skin, pain or swelling of the joints, severe or persistent diarrhea.
- Use or add barrier contraceptive if using hormonal contraception.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug