Viracept Drug Information

in combination with other antiretroviral agents is indicated for the treatment of HIV-1 infection. VIRACEPT is a protease inhibitor indicated for the treatment of HIV-1 infection in combination with other antiretroviral agents.

• Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
• Most common adverse reactions (≥2%) of moderate or severe intensity in adults and adolescents (13 years and older) are diarrhea, nausea, rash, and flatulence ( 6.1 )
• Most common adverse reactions in pediatric patients (2 to less than 13 years) are diarrhea, leukopenia/neutropenia, rash, anorexia, and abdominal pain. ( 6.2 ) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer Inc at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience: Adults and Adolescents (13 years and older) The safety of VIRACEPT was studied in over 5000 patients who received drug either alone or in combination with nucleoside analogues. The majority of adverse events were of mild intensity. The most frequently reported adverse event among patients receiving VIRACEPT was diarrhea, which was generally of mild to moderate intensity. Drug-related clinical adverse experiences of moderate or severe intensity in ≥2% of patients treated with VIRACEPT coadministered with d4T and 3TC (Study 542) for up to 48 weeks, or with ZDV plus 3TC (Study 511) for up to 24 weeks are presented in Table 4. Table 4: Percentage of Patients with Treatment-Emergent Includes those adverse events at least possibly, probably or definitely related to study drug or of unknown relationship and excludes concurrent HIV conditions Adverse Events of Moderate or Severe Intensity Reported in ≥ 2% of Adult and Adolescent Patients Study 511 Study 542 24 weeks 48 weeks Adverse Events Placebo + ZDV/3TC (n=101) 500 mg TID VIRACEPT + ZDV/3TC (n=97) 750 mg TID VIRACEPT + ZDV/3TC (n=100) 1250 mg BID VIRACEPT + d4T/3TC (n=344) 750 mg TID VIRACEPT + d4T/3TC (n=210) Digestive System Diarrhea 3% 14% 20% 20% 15% Nausea 4% 3% 7% 3% 3% Flatulence 0 5% 2% 1% 1% Skin/Appendages Rash 1% 1% 3% 2% 1% Adverse events occurring in less than 2% of patients receiving VIRACEPT in all phase 2 and 3 clinical trials and considered at least possibly related or of unknown relationship to treatment and of at least moderate severity are listed below. Body as a Whole : abdominal pain, accidental injury, allergic reaction, asthenia, back pain, fever, headache, malaise, pain, and redistribution/accumulation of body fat [see Warnings and Precautions (5.7) ] . Digestive System : anorexia, dyspepsia, epigastric pain, gastrointestinal bleeding, hepatitis, mouth ulceration, pancreatitis, and vomiting. Hemic/Lymphatic System : anemia, leukopenia, and thrombocytopenia. Metabolic/Nutritional System : increases in alkaline phosphatase, amylase, creatine phosphokinase, lactic dehydrogenase, SGOT, SGPT, and gamma-glutamyl transpeptidase; hyperlipemia, hyperuricemia, hyperglycemia, hypoglycemia, dehydration, and liver function tests abnormal. Musculoskeletal System : arthralgia, arthritis, cramps, myalgia, myasthenia, and myopathy. Nervous System : anxiety, depression, dizziness, emotional lability, hyperkinesia, insomnia, migraine, paresthesia, seizures, sleep disorder, somnolence, and suicide ideation. Respiratory System : dyspnea, pharyngitis, rhinitis, and sinusitis. Skin/Appendages : dermatitis, folliculitis, fungal dermatitis, maculopapular rash, pruritus, sweating, and urticaria. Special Senses : acute iritis and eye disorder. Urogenital System : kidney calculus, sexual dysfunction, and urine abnormality. Laboratory Abnormalities The percentage of patients with marked laboratory abnormalities in Studies 542 and 511 are presented in Table 5. Marked laboratory abnormalities are defined as a Grade 3 or 4 abnormality in a patient with a normal baseline value, or a Grade 4 abnormality in a patient with a Grade 1 abnormality at baseline. Table 5: Percentage of Patients by Treatment Group with Marked Laboratory Abnormalities Marked laboratory abnormalities are defined as a shift from Grade 0 at baseline to at least Grade 3 or from Grade 1 to Grade 4 in >2% of Patients Study 511 Study 542 Placebo + ZDV/3TC (n=101) 500 mg TID VIRACEPT + ZDV/3TC (n=97) 750 mg TID VIRACEPT + ZDV/3TC (n=100) 1250 mg BID VIRACEPT + d4T/3TC (n=344) 750 mg TID VIRACEPT + d4T/3TC (n=210) Hematology Hemoglobin 6% 3% 2% 0 0 Neutrophils 4% 3% 5% 2% 1% Lymphocytes 1% 6% 1% 1% 0 Chemistry ALT (SGPT) 6% 1% 1% 2% 1% AST (SGOT) 4% 1% 0 2% 1% Creatine Kinase 7% 2% 2% NA NA 6.2 Clinical Trials Experience: Pediatrics (2 to less than 13 years of age) VIRACEPT has been studied in approximately 400 pediatric patients in clinical trials from birth to 13 years of age. The adverse event profile seen during pediatric clinical trials was similar to that for adults. The most commonly reported drug-related, treatment-emergent adverse events reported in the pediatric studies included: diarrhea, leukopenia/neutropenia, rash, anorexia, and abdominal pain. Diarrhea, regardless of assigned relationship to study drug, was reported in 39% to 47% of pediatric patients receiving VIRACEPT in 2 of the larger treatment trials. Leukopenia/neutropenia was the laboratory abnormality most commonly reported as a significant event across the pediatric studies. 6.3 Postmarketing Experience The following adverse reactions have been identified during post-approval use of VIRACEPT. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Body as a Whole : hypersensitivity reactions (including bronchospasm, moderate to severe rash, fever, and edema). Cardiovascular System : QTc prolongation, torsades de pointes . Digestive System : jaundice. Metabolic/Nutritional System : bilirubinemia, metabolic acidosis.

• Coadministration of VIRACEPT with other drugs ( CYP3A substrates) can alter the concentration of these other drugs , and other drugs (inhibitors and/or inducers of CYP3A or CYP2C19) may alter the concentrations of nelfinavir. The potential drug-drug concentrations must be considered prior to and during therapy ( 4 , 7 , 12.3 )
• VIRACEPT should be given with food one hour after or more than 2 hours before didanosine ( 7 ) 7.1 Potential for VIRACEPT to Affect Other Drugs Nelfinavir is an inhibitor of CYP3A. Coadministration of VIRACEPT and drugs primarily metabolized by CYP3A (e.g., dihydropyridine calcium channel blockers, HMG-CoA reductase inhibitors, immunosuppressants, and PDE5 inhibitors) may result in increased plasma concentrations of such drugs that could increase or prolong both its therapeutic and adverse effects (see Tables 3 and 6 ). 7.2 Potential for Other Drugs to Affect VIRACEPT Nelfinavir is metabolized by CYP3A and CYP2C19. Coadministration of VIRACEPT and drugs that induce CYP3A or CYP2C19, such as rifampin, may decrease nelfinavir plasma concentrations and reduce its therapeutic effect. Coadministration of VIRACEPT and drugs that inhibit CYP3A or CYP2C19 may increase nelfinavir plasma concentrations. 7.3 Established and Other Potentially Significant Drug Interactions Table 6 provides the effect on concentrations of VIRACEPT or concomitant drug as a result of coadministration with VIRACEPT. These recommendations are based on either drug interaction studies or predicted interactions due to the expected magnitude of interaction and potential for serious adverse events or loss of efficacy. Table 6: Established and Other Potentially Significant Drug Interactions: Alteration in Dose or Regimen May Be Recommended Based on Drug Interaction Studies [see Clinical Pharmacology (12.3) ( Tables 12 and 13 ) for magnitude of interaction] Concomitant Drug Class: Drug Name Effect on Concentration Clinical Comment HIV Antiviral Agents: Reverse Transcriptase Inhibitors Delavirdine ↑ nelfinavir (C min ) ↓ delavirdine Concentrations of nelfinavir were increased while concentrations of delavirdine were decreased when the two agents were coadministered. Appropriate doses of the combination, with respect to safety and efficacy, have not been established. Nevirapine ↓ nelfinavir (C min ) Concentrations of nelfinavir were decreased when coadministered with nevirapine. An appropriate dose of nelfinavir with respect to safety and efficacy has not been established. Didanosine ↔ nelfinavir There was no change in nelfinavir concentration when coadministered with didanosine. However, it is recommended that didanosine be administered on an empty stomach; therefore, didanosine should be given one hour before or two hours after VIRACEPT (given with food). HIV Antiviral Agents: Protease Inhibitors Indinavir ↑ nelfinavir ↑ indinavir Concentrations of both indinavir and nelfinavir were increased when the two agents were coadministered. Appropriate doses for these combinations, with respect to safety and efficacy, have not been established. Ritonavir ↑ nelfinavir ↔ ritonavir Concentrations of nelfinavir were increased when coadministered with ritonavir. An appropriate dose of nelfinavir for this combination, with respect to safety and efficacy, has not been established. Saquinavir ↑ nelfinavir ↑ saquinavir Concentrations of both saquinavir and nelfinavir were increased when the two agents were coadministered. Appropriate doses for these combinations, with respect to safety and efficacy, have not been established. ANTICOAGULANT Warfarin Warfarin Coadministration of warfarin and VIRACEPT may affect concentrations of warfarin. It is recommended that the INR (international normalized ratio) be monitored carefully during treatment with VIRACEPT, especially when commencing therapy. ANTICONVULSANTS Carbamazepine Phenobarbital Phenytoin ↓ nelfinavir ↓ phenytoin Concentrations of nelfinavir may be decreased. VIRACEPT may not be effective due to decreased nelfinavir plasma concentrations in patients taking these agents concomitantly. Phenytoin plasma/serum concentrations should be monitored; phenytoin dose may require adjustment to compensate for altered phenytoin concentration. ANTIDEPRESSANT Trazodone ↑ trazodone Concomitant use of trazodone and VIRACEPT 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 VIRACEPT, the combination should be used with caution and a lower dose of trazodone should be considered. ANTIGOUT Colchicine ↑ colchicines Patients with renal or hepatic impairment should not be given colchicine with VIRACEPT due to the risk of colchicine toxicity. Treatment of gout flares – co- administration of colchicine in patients on VIRACEPT: 0.6 mg (1 tablet) × 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 – coadministration of colchicine in patients on VIRACEPT: 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)– coadministration of colchicine in patients on VIRACEPT: Maximum daily dose of 0.6 mg (may be given as 0.3 mg twice a day). ANTIMYCOBACTERIAL Rifabutin ↑ rifabutin ↓ nelfinavir (750 mg TID) ↔ nelfinavir (1250 mg BID) It is recommended that the dose of rifabutin be reduced to one-half the usual dose when administered with VIRACEPT; 1250 mg BID is the preferred dose of VIRACEPT when coadministered with rifabutin. ENDOTHELIN RECEPTOR ANTAGONIST Bosentan ↑ bosentan Concentrations of bosentan may be increased when coadministered with VIRACEPT. Coadministration of bosentan in patients on VIRACEPT or coadministration of VIRACEPT 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 ↑ rosuvastatin Titrate atorvastatin dose carefully and use the lowest necessary dose; do not exceed atorvastatin 40 mg/day. IMMUNOSUPPRESSANTS Cyclosporine Tacrolimus Sirolimus ↑ immuno-suppressants ↑ nelfinavir Concentrations of these immunosuppressants and nelfinavir may be increased by coadministration of these agents with nelfinavir. INHALED BETA AGONIST Salmeterol ↑ salmeterol Concurrent administration of salmeterol with VIRACEPT 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 Concomitant use of fluticasone propionate and VIRACEPT may increase plasma concentrations of fluticasone propionate. Use with caution. Consider alternatives to fluticasone propionate, particularly for long-term use. MACROLIDE ANTIBIOTIC Azithromycin ↑ azithromycin Dose adjustment of azithromycin is not recommended, but close monitoring for known side effects such as liver enzyme abnormalities and hearing impairment is warranted. NARCOTIC ANALGESIC Methadone ↓ methadone Concentrations of methadone were decreased when coadministered with VIRACEPT. Dosage of methadone may need to be increased when coadministered with VIRACEPT. HORMONAL CONTRACEPTIVES Ethinyl estradiol Norethindrone ↓ ethinyl estradiol ↓ norethindrone Concentrations of ethinyl estradiol and norethindrone were decreased when coadministered with VIRACEPT. Alternative or additional contraceptive measures should be used when oral contraceptives containing ethinyl estradiol or norethindrone and VIRACEPT are coadministered. PDE5 INHIBITORS Sildenafil Vardenafil Tadalafil ↑ PDE5 Inhibitors Concomitant use of PDE5 inhibitors and VIRACEPT should be undertaken with caution. May result in an increase in PDE5 inhibitor-associated adverse events, including hypotension, syncope, visual disturbances, and priapism. Use of PDE5 inhibitors for pulmonary arterial hypertension (PAH):
• Use of sildenafil (REVATIO) is contraindicated when used for the treatment of pulmonary arterial hypertension (PAH) [see Contraindications (4) ] .
• The following dose adjustments are recommended for use of tadalafil (ADCIRCA™) with VIRACEPT: Coadministration of ADCIRCA in patients on VIRACEPT or coadministration of VIRACEPT 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 PDE5 inhibitors for erectile dysfunction: Sildenafil at a single dose not exceeding 25 mg in 48 hours, vardenafil at a single dose not exceeding 2.5 mg in 24 hours, or tadalafil at a single dose not exceeding 10 mg dose in 72 hours, is recommended. Use with increased monitoring for adverse events. PROTON PUMP INHIBITORS Omeprazole ↓ nelfinavir Omeprazole decreases the plasma concentrations of nelfinavir. Concomitant use of proton pump inhibitors and VIRACEPT may lead to a loss of virologic response and development of resistance. ANTIPSYCHOTICS Quetiapine ↑ quetiapine Initiation of VIRACEPT in patients taking quetiapine: Consider alternative antiretroviral therapy to avoid increases in quetiapine drug exposures. If coadministration is necessary, reduce the quetiapine dose to 1/6 of the current dose and monitor for quetiapine-associated adverse reactions. Refer to the quetiapine prescribing information for recommendations on adverse reaction monitoring. Initiation of quetiapine in patients taking VIRACEPT: Refer to the quetiapine prescribing information for initial dosing and titration of quetiapine.

Pregnancy Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to VIRACEPT during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263. Risk Summary Published reports of hepatic adverse events ranging from elevated liver enzymes to hepatic failure in pregnant patients exposed to nelfinavir have been reported (see Clinical Considerations ). Due to VIRACEPT's overall adverse event profile, including hepatic adverse events, and literature reports of decreased exposures in second and third trimesters, consider alternative antiretroviral drugs during pregnancy. Available data from the APR suggests a statistically significant increase in overall risks of major birth defects with first trimester exposure with nelfinavir (3.9%) when compared with the background rate of 2.7% in one U.S. reference population (the Metropolitan Atlanta Congenital Defects Program ), but the risk is similar to the background rate of 4.2% reported in another U.S. reference population (the Texas Birth Defects Registry ). No pattern of defects was identified by the APR. The clinical relevance of this statistical finding is uncertain (see Data ). The estimated background risk of major birth defects and miscarriage for the indicated populations is unknown.

In the U.S. general population, the estimated background risk of major birth defects and miscarriages in clinically recognized pregnancies is 2 to 4% and 15 to 20% respectively. In animal reproductive studies, no effects on embryo-fetal development were observed when nelfinavir was administered orally to pregnant rats and rabbits during organogenesis at systemic exposures similar to or less than human exposure (based on AUC) at the maximum recommended human dose (MRHD), respectively (see Data ). Clinical Considerations Maternal Adverse Reactions There have been reports of hepatic adverse events ranging from elevated liver enzymes to hepatic failure in pregnant patients receiving nelfinavir as part of combination treatment of HIV-1 infection. Consider alternative antiretroviral drugs during pregnancy.

If VIRACEPT is used during pregnancy, clinical monitoring is recommended . Data Human Data Based on prospective reports to the APR of over 1,200 live births following first trimester and over 2,700 live births following second and third trimester exposure to nelfinavir-containing regimens, there was an increase in overall rates of major birth defects (n=47) with nelfinavir when compared with the background birth defect rate of 2.7% in the U.S. reference population of the MACDP. The prevalence of birth defects in live births was 3.9% (95% CI: 2.9% to 5.1%) with first trimester exposure to nelfinavir-containing regimens and 3.1% (95% CI: 2.5% to 3.9%) with the second/third trimester exposure to nelfinavir-containing regimens. The rate for nelfinavir-containing regimens is greater than the overall rates of defects in the MACDP (2.7%) but less than rates of defects in the TBDR (4.2%). Methodological limitations of the APR include the use of MACDP as the external comparator group. Limitations of using an external comparator include differences in methodology and populations, as well as confounding due to the underlying disease; these limitations preclude an accurate comparison of outcomes.

The MACDP population is not disease specific, evaluates women and infants from a limited geographic area, and does not include outcomes for births that occurred at <20 weeks gestation. Animal Data Nelfinavir was administered orally to pregnant rats and rabbits during organogenesis, from gestation day 6 to 17 (rats) and 7 to 20 (rabbits). There were no effects on fetal development or maternal toxicity when nelfinavir was administered to pregnant rats at systemic exposures (AUC) similar to human exposure. Administration of nelfinavir to pregnant rabbits resulted in no fetal development effects up to a dose at which a slight decrease in maternal body weight was observed; however, even at the highest dose evaluated, systemic exposure in rabbits was significantly lower than human exposure.

Additional studies in rats indicated that exposure to nelfinavir in females from mid-pregnancy through lactation (gestation day 6 to lactation day 20) had no effect on the survival, growth, and development of the offspring. Subsequent reproductive performance of these offspring was also not affected by maternal exposure to nelfinavir.

Pediatric Use The safety, tolerability, pharmacokinetic profile and efficacy of VIRACEPT were evaluated in HIV infected pediatric patients from 2 to 13 years of age in multicenter clinical trials, Study 556 and PACTG 337 . In patients less than 2 years of age, VIRACEPT was found to be safe at the doses studied, but a reliably effective dose could not be established . The pharmacokinetic profile, safety and antiviral activity of VIRACEPT in adolescent patients 13 years and older is supported by data from the adult clinical trials where some trials allowed enrolment of subjects 13 years and older. Thus, the data for adolescents and adults were analyzed collectively .

• Coadministration of VIRACEPT is contraindicated with drugs that are highly dependent on CYP3A for clearance and for which elevated plasma concentrations are associated with serious and/or life-threatening events. These drugs and other contraindicated drugs (which may lead to reduced efficacy of nelfinavir) are listed in Table 3 [also see Drug Interactions (7) , Table 6 ] . Table 3: Drugs That Are Contraindicated With VIRACEPT Drug Class Drugs Within Class That Are Contraindicated With VIRACEPT Clinical Comment Alpha 1-adrenoreceptor antagonist Alfuzosin Potentially increased alfuzosin concentrations can result in hypotension. Antiarrhythmics Amiodarone, quinidine Potential for serious and/or life-threatening cardiac arrhythmia. Antimycobacterial Agents Rifampin Plasma concentrations of nelfinavir can be reduced by concomitant use of rifampin. This may lead to loss of therapeutic effect and possible development of resistance to VIRACEPT or other coadministered antiretroviral agents. Antipsychotics Lurasidone Pimozide Potential for serious and/or life-threatening reactions. Potential for serious and/or life threatening reactions such as cardiac arrhythmias. Ergot Derivatives Dihydroergotamine, ergotamine, methylergonovine Potential for serious and/or life threatening reactions such as ergot toxicity characterized by peripheral vasospasm and ischemia of the extremities and other tissues. GI Motility Agent Cisapride Potential for serious and/or life threatening reactions such as cardiac arrhythmias. Herbal products St. John's wort ( Hypericum perforatum ) Plasma concentrations of nelfinavir can be reduced by concomitant use of the herbal preparation St. John's wort. This may lead to loss of therapeutic effect and possible development of resistance to VIRACEPT or other coadministered antiretroviral agents. HMG-CoA Reductase Inhibitors Lovastatin, Simvastatin Potential for serious reactions such as myopathy including rhabdomyolysis. PDE5 Inhibitors Sildenafil (Revatio ® ) [for treatment of pulmonary arterial hypertension] See Drug Interactions , Table 6 for coadministration of sildenafil and tadalafil when dosed for erectile dysfunction. A safe and effective dose has not been established when used with nelfinavir. There is increased potential for sildenafil-associated adverse events (which include visual disturbances, hypotension, prolonged erection, and syncope). Sedative/Hypnotics Triazolam, oral midazolam Potential for serious and/or life threatening reactions such as prolonged or increased sedation or respiratory depression.
• Coadministration with drugs that are highly dependent on CYP3A for clearance and which elevated concentrations are associated with serious and/or life-threatening events ( 4 )

Human experience of acute overdose with VIRACEPT is limited. There is no specific antidote for overdose with VIRACEPT. If indicated, elimination of unabsorbed drug should be achieved by emesis or gastric lavage. Administration of activated charcoal may also be used to aid removal of unabsorbed drug.

Since nelfinavir is highly protein bound, dialysis is unlikely to significantly remove drug from blood.