INDINAVIR SULFATE
| INDINAVIR SULFATe (in-din'a-vir) Crixivan Classifications: antiviral agent; protease inhibitor; Therapeutic: antiviral; protease inhibitor Prototype: Saquinavir Pregnancy Category: C |
Availability
100 mg, 200 mg, 333 mg, 400 mg capsules
Action
Indinavir is an HIV protease inhibitor. HIV protease is an enzyme required to produce the polyprotein precursors of the functional proteins in infectious HIV. Indinavir binds to the protease active site and thus inhibits activity of the enzyme.
Therapeutic Effect
Protease inhibitors prevent cleavage of the HIV viral polyproteins, resulting in formation of immature noninfectious virus particles.
Uses
Treatment of HIV infection, usually in combination with other antiretroviral agents or protease inhibitors.
Contraindications
Hypersensitivity to indinavir; pregnancy (category C), lactation.
Cautious Use
Hepatic dysfunction, renal impairment, history of nephrolithiasis, diabetes mellitus; history of adverse responses to other protease inhibitors. Safety and efficacy in children are not established.
Route & Dosage
| HIV Adult: PO 800 mg (2 x 400 mg) q8h 1 h before or 2 h after meal With ritonavir: 800 mg b.i.d. plus 100–200 mg ritonavir b.i.d. |
Administration
Oral- Give with water on an empty stomach 1 h before or 2 h after meal; if needed, may be given with a very light meal or beverage.
- Note: When didanosine and indinavir are ordered concurrently, give each on empty stomach at least 1 h apart.
- Do not administer concurrently with midazolam or triazolam.
- Store tightly closed with desiccant in original bottle.
Adverse Effects (≥1%)
CNS: Fatigue, headache, insomnia, dizziness, somnolence, nervousness, agitation, anxiety, paresthesia, peripheral neuropathy, tremor, vertigo. CV: Palpitations. Hematologic: Anemia, splenomegaly, lymphadenopathy. GI: Nausea, diarrhea, abdominal discomfort, dyspepsia, stomatitis, anorexia, dry mouth, cholecystitis, cholestasis, constipation, flatulence. Skin: Body odor, rash, pruritus, seborrhea, skin ulceration, dry skin, sweating, urticaria. Other: Myalgia, allergic reaction, bronchitis, cough, rhinitis, taste alterations, visual disturbances, hyperglycemia, diabetes, kidney stones.Interactions
Drug: Rifabutin, rifampin significantly decrease indinavir levels. Ketoconazole significantly increases indinavir levels. Indinavir could inhibit the metabolism and increase the toxicity of midazolam, sildenafil, tadalafil, trazodone, triazolam, vardenafil. Indinavir and didanosine should be administered at least 1 h apart on empty stomach to permit full absorption of each; increased ergotamine toxicity with indinavir. Herbal: St. John's wort, garlic decreases antiretroviral activity of indinavir.Pharmacokinetics
Absorption: Rapidly absorbed from GI tract; a meal high in calories, fat, and protein significantly reduces absorption. Distribution: 60% protein bound. Metabolism: In liver by cytochrome P4503A4 (CYP3A4). Elimination: Primarily in feces (>80%), 20% in urine.Nursing Implications
Assessment & Drug Effects
- Lab tests: Monitor CBC with differential and platelet count, liver function tests, CPK, urinalysis, and serum amylase periodically.
- Assess for S&S of renal dysfunction, respiratory dysfunction, GI distress, and other common adverse effects.
Patient & Family Education
- Learn drug interactions and potential adverse reactions. Drink plenty of liquids to minimize risk of renal stones.
- Notify physician of flank pain, hematuria, S&S of jaundice, or other distressing adverse effects.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug