II. Indications
-
HIV Infection (as part of combination therapy)
- Has been replaced by newer Protease Inhibitors with fewer adverse effects
- Among the first Protease Inhibitors for HIV (FDA approved in 1996)
III. Mechanism
IV. Efficacy
- When originally studied in the 1990s, Indinavir was very effective in combination with Zidovudine (AZT)
- Newer Protease Inhibitors are combined with boosters (e.g. Ritonavir, Cobicistat) and are used with other Antiretrovirals
V. Medications
- Capsules: 100, 200, 400 mg
VI. Dosing
- Adults (as part of combination therapy with other Antiretrovirals)
- Indinavir 800 mg orally three times daily
- Indications to reduce dose to 600 mg orally three times daily
- Delavirdine
- Itraconazole or Ketoconazole
- Hepatic insufficiency
- Take on empty Stomach
- One hour before or 2 hours after a meal
- Concurrent food reduces concentration up to 80%
- Drink at least 1.5 Liters (50 oz) liquid per day
- Drink 150 ml water per hour for 3 hours after dose
- Avoids Nephrolithiasis and Interstitial Nephritis
VII. Adverse Effects
- See Protease Inhibitor for adverse effects attributed to the class
- Well tolerated
- Indirect Bilirubin (elevation in 10% of patients)
- Nephrolithiasis in 2-3% of patients
- Hyperglycemia
- Renal Insufficiency
- Alopecia
- Dry Skin
- Xerostomia
- Paronychia
- Gallstones
VIII. Drug Interactions
- See Protease Inhibitor
-
Drug Interactions are common with Protease Inhibitors
- Protease Inhibitors cause the most Drug Interactions of all Antiretrovirals
- Use formal Drug Interaction applications when prescribing
-
St. John's Wort
- May reduce Indinavir concentrations by 80%
- Piscitelli (2000) Lancet 355:547-8 [PubMed]
-
Rifabutin
- Decrease Rifabutin dose to 50% AND
- Increase Indinavir 1000 mg orally three times daily
- Medications contraindicated with Indinavir (a strong CYP3A4 Inhibitor)
- Alfuzosin
- Amiodarone
- Ergot alkaloids (e.g. Ergonovine, Ergotamine)
- Pimozide
- High dose Sildenafil (Revatio)
- Sedative Hypnotics (oral Midazolam, Triazolam, Alprazolam)
IX. Safety
- Avoid in Lactation (as with other Protease Inhibitors)
- Pregnancy Category C
- Risk of perinatal Hyperbilirubinemia