Side Effects of Crixivan (indinavir)

Does Crixivan (indinavir) cause side effects?

Crixivan (indinavir) is a type of antiviral medication called a protease inhibitor used to treat infections with the human immunodeficiency virus (HIV). 

During infection with HIV, the HIV virus multiplies within the body's cells. Viruses are released from the cells and spread throughout the body where they infect other cells. In this manner, HIV infection is perpetuated among new cells that the body produces continually. During the production of the viruses, new proteins are made. 

Some of the proteins are structural proteins, that, is, proteins that form the body of the virus. Other proteins are enzymes which manufacture DNA and other components for the new viruses. Protease is the enzyme that forms the new structural proteins and enzymes. 

Crixivan blocks the activity of protease and results in the formation of defective viruses that are unable to infect the body's cells. As a result, the number of viruses in the body (the viral load) decreases. Crixivan does not prevent the transmission of HIV among individuals, and it does not cure HIV infections or AIDS

Common side effects of Crixivan include

Serious side effects of Crixivan include

Drug interactions of Crixivan include triazolam, midazolam, alprazolam, pimozide, lovastatin, simvastatin, ergot derivatives, and amiodarone because of the risk of serious adverse effects resulting from Crixivan increasing the blood levels of these drugs.

  • Crixivan increases blood concentrations of stavudine, alfuzosin, oral contraceptives, and clarithromycin. Increased blood levels may result in more frequent side effects.
  • Crixivan decreases the blood concentration of didanosine in the body and can thereby reduce the effectiveness of didanosine.
  • Crixivan also may inhibit the break-down of the cholesterol-lowering drugs lovastatin, simvastatin, and atorvastatin. This may increase the risk of muscle breakdown (rhabdomyolysis) that may be seen when these drugs accumulate in the body.
  • Ketoconazole, itraconazole, delavirdine, and clarithromycin can increase blood levels of Crixivan and result in more frequent or severe side effects from Crixivan. Rifampin, rifabutin, St. John's wort, and efavirenz decrease the blood levels of Crixivan and thus can reduce the effect of Crixivan.
  • Crixivan increases blood levels of sildenafil and the risk of side effects such as low blood pressure, prolonged erection, and fainting

Use of Crixivan during pregnancy has not been adequately evaluated. It is unknown if Crixivan is excreted in breast milk. Nevertheless, HIV-infected mothers should not breastfeed because of the potential risk of transmitting HIV to an infant that is not infected.

What are the important side effects of Crixivan (indinavir)?

The most common side effects of indinavir are:

Other important side effects include:

Like other protease inhibitors, use of indinavir may be associated with:

  • redistribution or accumulation of body fat,
  • increased blood cholesterol, and
  • worsening of diabetes.

Kidney stones may be prevented by adequate fluid intake. Adequate fluid intake can be achieved by consuming at least 48 ounces of fluid daily. Immune reconstitution syndrome which is an inflammatory response to infection may occur in patients treated with combination antiretroviral therapy.

Crixivan (indinavir) side effects list for healthcare professionals

Clinical Trials In Adults

  • Nephrolithiasis/urolithiasis, including flank pain with or without hematuria (including microscopic hematuria), has been reported in approximately 12.4% (301/2429; range across individual trials: 4.7% to 34.4%) of patients receiving Crixivan at the recommended dose in clinical trials with a median follow-up of 47 weeks (range: 1 day to 242 weeks; 2238 patient-years follow-up).
  • The cumulative frequency of nephrolithiasis events increases with duration of exposure to Crixivan; however, the risk over time remains relatively constant.
  • Of the patients treated with Crixivan who developed nephrolithiasis/urolithiasis in clinical trials during the double-blind phase, 2.8% (7/246) were reported to develop hydronephrosis and 4.5% (11/246) underwent stent placement.
  • Following the acute episode, 4.9% (12/246) of patients discontinued therapy.
  • Asymptomatic hyperbilirubinemia (total bilirubin ≥ 2.5 mg/dL), reported predominantly as elevated indirect bilirubin, has occurred in approximately 14% of patients treated with Crixivan. In < 1% this was associated with elevations in ALT or AST.
  • Hyperbilirubinemia and nephrolithiasis/urolithiasis occurred more frequently at doses exceeding 2.4 g/day compared to doses ≤ 2.4 g/day.
  • Clinical adverse experiences reported in ≥ 2% of patients treated with Crixivan alone, Crixivan in combination with zidovudine or zidovudine plus lamivudine, zidovudine alone, or zidovudine plus lamivudine are presented in Table 10.

Table 10: Clinical Adverse Experiences Reported in ≥ 2% of Patients

Adverse ExperienceStudy 028 Considered Drug-Related and of Moderate or Severe IntensityStudy ACTG 320 of Unknown Drug Relationship and of Severe or Life-threatening Intensity
Crixivan Percent
(n=332)
Crixivan plus Zidovudine Percent
(n=332)
Zidovudine Percent
(n=332)
Crixivan plus Zidovudine plus Lamivudine Percent
(n=571)
Zidovudine plus Lamivudine Percent
(n=575)
Body as a Whole
  Abdominal pain16.616.012.01.90.7
  Asthenia/ fatigue2.14.23.62.44.5
  Fever1.51.52.13.83.0
  Malaise2.12.71.800
Digestive System
  Nausea11.731.919.62.81.4
  Diarrhea3.33.02.40.91.2
  Vomiting8.417.89.01.41.4
  Acid regurgitation2.75.41.80.40
  Anorexia2.75.43.00.50.2
  Appetite increase2.11.51.200
  Dyspepsia1.52.70.900
  Jaundice1.52.10.300
Hemic and Lymphatic System
  Anemia0.61.22.12.43.5
Musculoskeletal System
  Back pain8.44.51.50.90.7
Nervous System/ Psychiatric
  Headache5.49.66.02.42.8
  Dizziness3.03.90.90.50.7
  Somnolence2.43.33.300
Skin and Skin Appendage
  Pruritus4.22.41.80.50
  Rash1.20.62.41.10.5
Respiratory System
  Cough1.50.30.61.61.0
  Difficulty breathing/ dyspnea/ shortness of breath00.60.31.81.0
Urogenital System
  Nephrolithiasis/ urolithiasis8.77.82.12.60.3
  Dysuria1.52.40.30.40.2
Special Senses
  Taste perversion2.78.41.20.20
*Including renal colic, and flank pain with and without hematuria

  • In Phase I and II controlled trials, the following adverse events were reported significantly more frequently by those randomized to the arms containing Crixivan than by those randomized to nucleoside analogues: rash, upper respiratory infection, dry skin, pharyngitis, taste perversion.
  • Selected laboratory abnormalities of severe or life-threatening intensity reported in patients treated with Crixivan alone, Crixivan in combination with zidovudine or zidovudine plus lamivudine, zidovudine alone, or zidovudine plus lamivudine are presented in Table 11.

Table 11: Selected Laboratory Abnormalities of Severe or Life-threatening Intensity Reported in Studies 028 and ACTG 320

Study 028 Considered Drug-Related and of Moderate or Severe IntensityStudy ACTG 320 of Unknown Drug Relationship and of Severe or Life-threatening Intensity
Crixivan Percent
(n=329)
Crixivan plus Zidovudine Percent
(n=320)
Zidovudine Percent
(n=330)
Crixivan plus Zidovudine plus Lamivudine Percent
(n=571)
Zidovudine plus Lamivudine Percent
(n=575)
Hematology
Decreased hemoglobin < 7.0 g/dL0.60.93.32.43.5
Decreased platelet count < 50 THS/mm³0.90.91.80.20.9
Decreased neutrophils < 0.75 THS/mm³2.42.26.75.114.6
Blood chemistry
Increased ALT > 500% ULN*4.94.13.02.62.6
Increased AST > 500% ULN3.72.82.73.32.8
Total serum bilirubin > 250% ULN11.99.70.66.11.4
Increased serum amylase > 200% ULN2.11.91.80.90.3
Increased glucose > 250 mg/dL0.90.90.61.61.9
Increased creatinine > 300% ULN000.60.20
*Upper limit of the normal range.

Post-Marketing Experience

Laboratory Abnormalities

What drugs interact with Crixivan (indinavir)?

Indinavir is an inhibitor of the cytochrome P450 isoform CYP3A4. Coadministration of Crixivan and drugs primarily metabolized by CYP3A4 may result in increased plasma concentrations of the other drug, which could increase or prolong its therapeutic and adverse effects.

Indinavir is metabolized by CYP3A4. Drugs that induce CYP3A4 activity would be expected to increase the clearance of indinavir, resulting in lowered plasma concentrations of indinavir. Coadministration of Crixivan and other drugs that inhibit CYP3A4 may decrease the clearance of indinavir and may result in increased plasma concentrations of indinavir.

Table 8: Drugs That Should Not Be Coadministered with Crixivan

Drug Class: Drug NameClinical Comment
Alpha 1-adrenoreceptor antagonist: alfuzosinPotentially increased alfuzosin concentrations can result in hypotension.
Antiarrhythmics: amiodaroneCONTRAINDICATED due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias.
Antimycobacterial: rifampinMay lead to loss of virologic response and possible resistance to Crixivan or to the class of protease inhibitors or other coadministered antiretroviral agents.
Ergot derivatives: dihydroergotamine, ergonovine, ergotamine, methylergonovineCONTRAINDICATED due to potential for serious and/or life-threatening reactions such as acute ergot toxicity characterized by peripheral vasospasm and ischemia of the extremities and other tissues.
GI motility agents: cisaprideCONTRAINDICATED due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias.
Herbal products: St. John’s wort (Hypericum perforatum)May lead to loss of virologic response and possible resistance to Crixivan or to the class of protease inhibitors.
HMG-CoA Reductase inhibitors: lovastatin, simvastatinCONTRAINDICATED due to an increased risk for serious reactions such as myopathy including rhabdomyolysis.
Neuroleptic: pimozideCONTRAINDICATED due to potential for serious and/or life-threatening reactions such as cardiac arrhythmias.
PDE5 inhibitor: Revatio (sildenafil) [for treatment of pulmonary arterial hypertension]A safe and effective dose has not been established when used with Crixivan. There is increased potential for sildenafil-associated adverse events (which include visual disturbances, hypotension, prolonged erection, and syncope).
Protease inhibitor: atazanavirBoth Crixivan and atazanavir are associated with indirect (unconjugated) hyperbilirubinemia. Combinations of these drugs have not been studied and coadministration of Crixivan and atazanavir is not recommended.
Sedative/hypnotics: Oral midazolam, triazolam, alprazolamCONTRAINDICATED due to potential for serious and/or life-threatening reactions such as prolonged or increased sedation or respiratory depression.

Table 9: Established and Other Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies or Predicted Interaction

Drug NameEffectClinical Comment
HIV Antiviral Agents
Delavirdine↑ indinavir concentrationDose reduction of Crixivan to 600 mg every 8 hours should be considered when taking delavirdine 400 mg three times a day.
DidanosineIndinavir and didanosine formulations containing buffer should be administered at least one hour apart on an empty stomach.
Efavirenz↓indinavir concentrationThe optimal dose of indinavir, when given in combination with efavirenz, is not known. Increasing the indinavir dose to 1000 mg every 8 hours does not compensate for the increased indinavir metabolism due to efavirenz.
Nelfinavir↑ indinavir concentrationThe appropriate doses for this combination, with respect to efficacy and safety, have not been established.
Nevirapine↓ indinavir concentrationIndinavir concentrations may be decreased in the presence of nevirapine. The appropriate doses for this combination, with respect to efficacy and safety, have not been established.
Ritonavir↑indinavir concentration
↑ritonavir concentration
The appropriate doses for this combination, with respect to efficacy and safety, have not been established. Preliminary clinical data suggest that the incidence of nephrolithiasis is higher in patients receiving indinavir in combination with ritonavir than those receiving Crixivan 800 mg q8h.
Saquinavir↑ saquinavir concentrationThe appropriate doses for this combination, with respect to efficacy and safety, have not been established.
Other Agents
Antiarrhythmics: bepridil, lidocaine (systemic) and quinidine↑antiarrhythmic agents concentrationCaution is warranted and therapeutic concentration monitoring is recommended for antiarrhythmics when coadministered with Crixivan.
Anticonvulsants: carbamazepine, phenobarbital, phenytoin↓ indinavir concentrationUse with caution. Crixivan may not be effective due to decreased indinavir concentrations in patients taking these agents concomitantly.
Antidepressant: Trazodone↑trazodone concentrationConcomitant use of trazodone and Crixivan may increase plasma concentrations of trazodone. Adverse events of nausea, dizziness, hypotension and syncope have been observed following coadministration of trazodone and ritonavir. If trazodone is used with a CYP3A4 inhibitor such as Crixivan, the combination should be used with caution and a lower dose of trazodone should be considered.
Anti-gout: Colchicine↑colchicine concentrationPatients with renal or hepatic impairment should not be given colchicine with Crixivan.
Treatment of gout flares:
Co-administration of colchicine in patients on Crixivan: 0.6 mg (1 tablet) x 1 dose, followed by 0.3 mg (half tablet) 1 hour later. Dose to be repeated no earlier than 3 days.
Prophylaxis of gout flares:
Co-administration of colchicine in patients on Crixivan:
If the original colchicine regimen was 0.6 mg twice a day, the regimen should be adjusted to 0.3 mg once a day. If the original colchicine regimen was 0.6 mg once a day, the regimen should be adjusted to 0.3 mg once every other day.
Treatment of familial Mediterranean fever (FMF):
Co-administration of colchicine in patients on Crixivan: Maximum daily dose of 0.6 mg (may be given as 0.3 mg twice a day).
Calcium Channel Blockers, Dihydropyridine: e.g., felodipine, nifedipine, nicardipine↑ dihydropyridine calcium channel blockers concentrationCaution is warranted and clinical monitoring of patients is recommended.
Clarithromycin↑clarithromycin concentration
↑indinavir concentration
The appropriate doses for this combination, with respect to efficacy and safety, have not been established.
Endothelin receptor antagonist: Bosentan↑bosentan concentrationCo-administration of bosentan in patients on Crixivan or coadministration of Crixivan in patients on bosentan: Start at or adjust bosentan to 62.5 mg once daily or every other day based upon individual tolerability.
HMG-CoA Reductase Inhibitors: atorvastatin, rosuvastatin↑atorvastatin concentration
↑rosuvastatin concentration
The atorvastatin and rosuvastatin doses should be carefully titrated; use the lowest dose necessary with careful monitoring during treatment with Crixivan.
Immunosuppressants: cyclosporine, tacrolimus, sirolimus↑immunosuppressant agents concentrationPlasma concentrations may be increased by Crixivan.
Inhaled beta agonist: Salmeterol↑salmeterolConcurrent administration of salmeterol with Crixivan is not recommended. The combination may result in increased risk of cardiovascular adverse events associated with salmeterol, including QT prolongation, palpitations and sinus tachycardia.
Inhaled/nasal steroid: Fluticasone↑fluticasone concentrationConcomitant use of fluticasone propionate and Crixivan may increase plasma concentrations of fluticasone propionate. Use with caution. Consider alternatives to fluticasone propionate, particularly for long-term use.
Fluticasone use is not recommended in situations where Crixivan is coadministered with a potent CYP3A4 inhibitor such as ritonavir unless the potential benefit to the patient outweighs the risk of systemic corticosteroid side effects.
Itraconazole↑indinavir concentrationDose reduction of Crixivan to 600 mg every 8 hours is recommended when administering itraconazole concurrently.
Ketoconazole↑ indinavir concentrationDose reduction of Crixivan to 600 mg every 8 hours should be considered.
Midazolam (parenteral administration)↑midazolam concentrationConcomitant use of parenteral midazolam with Crixivan may increase plasma concentrations of midazolam. Coadministration should be done in a setting which ensures close clinical monitoring and appropriate medical management in case of respiratory depression and/or prolonged sedation. Dosage reduction for midazolam should be considered, especially if more than a single dose of midazolam is administered. Coadministration of oral midazolam with Crixivan is CONTRAINDICATED (see Table 8).
Rifabutin↓ indinavir concentration ↑rifabutin concentrationDose reduction of rifabutin to half the standard dose and a dose increase of Crixivan to 1000 mg every 8 hours are recommended when rifabutin and Crixivan are coadministered.
Sildenafil↑ sildenafil concentration (only the use of sildenafil at doses used for treatment of erectile dysfunction has been studied with Crixivan)May result in an increase in PDE5 inhibitor-associated adverse events, including hypotension, syncope, visual disturbances, and priapism.
Use of sildenafil for pulmonary arterial hypertension (PAH):
Use of Revatio (sildenafil) is contraindicated when used for the treatment of pulmonary arterial hypertension (PAH).
Use of sildenafil for erectile dysfunction:
Sildenafil dose should not exceed a maximum of 25 mg in a 48-hour period in patients receiving concomitant Crixivan therapy. Use with increased monitoring for adverse events.
Tadalafil↑ tadalafil concentrationMay result in an increase in PDE5 inhibitor-associated adverse events, including hypotension, visual disturbances, and priapism.
Use of tadalafil for pulmonary arterial hypertension (PAH):
The following dose adjustments are recommended for use of Adcirca (tadalafil) with Crixivan:
Co-administration of Adcirca in patients on Crixivan or coadministration of Crixivan in patients on Adcirca:
Start at or adjust Adcirca to 20 mg once daily. Increase to 40 mg once daily based upon individual tolerability.
Use of tadalafil for erectile dysfunction:
Tadalafil dose should not exceed a maximum of 10 mg in a 72-hour period in patients receiving concomitant Crixivan therapy. Use with increased monitoring for adverse events.
Vardenafil↑vardenafil concentrationVardenafil dose should not exceed a maximum of 2.5 mg in a 24-hour period in patients receiving concomitant indinavir therapy.
Venlafaxine↓ indinavir concentrationIn a study of 9 healthy volunteers, venlafaxine administered under steady-state conditions at 150 mg/day resulted in a 28% decrease in the AUC of a single 800 mg oral dose of indinavir and a 36% decrease in indinavir Cmax. Indinavir did not affect the pharmacokinetics of venlafaxine and ODV. The clinical significance of this finding is unknown.

Summary

Crixivan (indinavir) is a type of antiviral medication called a protease inhibitor used to treat infections with the human immunodeficiency virus (HIV). Common side effects of Crixivan include abdominal pain, weakness, nausea, diarrhea, vomiting, headache, insomnia, abnormal taste sensation, and redistribution or accumulation of body fat. Use of Crixivan during pregnancy has not been adequately evaluated. It is unknown if Crixivan is excreted in breast milk. Nevertheless, HIV-infected mothers should not breastfeed because of the potential risk of transmitting HIV to an infant that is not infected.

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