Warnings for Invirase
Included as part of the "PRECAUTIONS" Section
Precautions for Invirase
Importance Of Co-Administration With Ritonavir
INVIRASE must be used in combination with ritonavir. Refer to the ritonavir full prescribing information for additional precautionary measures.
INVIRASE is not recommended for use in combination with cobicistat. Dosing recommendations for this combination have not been established. Cobicistat is also not recommended in combination with regimens containing ritonavir due to similar effects of cobicistat and ritonavir on CYP3A. Refer to the cobicistat full prescribing information for additional precautionary measures.
Risk Of Serious Adverse Reactions Due To Drug Interactions
Initiation of INVIRASE/ritonavir, a CYP3A inhibitor, in patients receiving medications metabolized by CYP3A or initiation of medications metabolized by CYP3A in patients already receiving INVIRASE/ritonavir, may increase plasma concentrations of medications metabolized by CYP3A. Initiation of medications that inhibit or induce CYP3A may increase or decrease concentrations of INVIRASE/ritonavir, respectively. These interactions may lead to:
- Clinically significant adverse reactions potentially leading to severe, life threatening, or fatal events from greater exposures of concomitant medications.
- Clinically significant adverse reactions from greater exposures of INVIRASE/ritonavir.
- Loss of therapeutic effect of INVIRASE/ritonavir and possible development of resistance.
See Table 2 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations [see DRUG INTERACTIONS]. Consider the potential for drug interactions prior to and during INVIRASE/ritonavir therapy; review concomitant medications during INVIRASE/ritonavir therapy; and monitor for the adverse reactions associated with the concomitant medications [see CONTRAINDICATIONS and DRUG INTERACTIONS].
If a serious or severe toxicity occurs during treatment with INVIRASE/ritonavir, discontinue INVIRASE/ritonavir. For concomitantly used drugs including antiretroviral agents used in combination with INVIRASE/ritonavir, prescribers should refer to the complete product information for these drugs for dose adjustment recommendations and for information regarding drug-associated adverse reactions.
PR Interval Prolongation
INVIRASE/ritonavir prolongs the PR interval in a dose-dependent fashion. Cases of second or third degree atrioventricular block have been reported rarely. Patients with underlying structural heart disease, pre-existing conduction system abnormalities, cardiomyopathies and ischemic heart disease may be at increased risk for developing cardiac conduction abnormalities. ECG monitoring is recommended in these patients [see QT Interval Prolongation]. Discontinue INVIRASE/ritonavir if significant arrhythmias, QT or PR prolongation occur.
The impact on the PR interval of coadministration of INVIRASE/ritonavir with other drugs that prolong the PR interval (including calcium channel blockers, beta-adrenergic blockers, digoxin and atazanavir) has not been evaluated. As a result, coadministration of INVIRASE/ritonavir with these drugs should be undertaken with caution, particularly with those drugs metabolized by CYP3A, and clinical monitoring is recommended [see CLINICAL PHARMACOLOGY].
For concomitantly used drugs, including antiretroviral agents used in combination with INVIRASE/ritonavir, physicians should refer to the complete product information for these drugs for dose adjustment recommendations and for information regarding drug-associated adverse reactions.
QT Interval Prolongation
INVIRASE/ritonavir causes dose-dependent QT prolongation. Torsade de pointes has been reported rarely post-marketing. Avoid INVIRASE/ritonavir in patients with long QT syndrome. ECG monitoring is recommended if therapy is initiated in patients with congestive heart failure, bradyarrhythmias, hepatic impairment and electrolyte abnormalities. Correct hypokalemia or hypomagnesemia prior to initiating INVIRASE/ritonavir and monitor these electrolytes periodically during therapy. Do not use in combination with drugs that both increase saquinavir plasma concentrations and prolong the QT interval (see Table 2) [see CLINICAL PHARMACOLOGY]. For concomitantly used drugs, including antiretroviral agents used in combination with INVIRASE/ritonavir, refer to the complete product information for these drugs for dose adjustment recommendations and for information regarding drug-associated adverse reactions [see CONTRAINDICATIONS and DRUG INTERACTIONS]. Discontinue INVIRASE/ritonavir if significant arrhythmias, QT or PR prolongation occurs.
Patients Initiating Therapy With INVIRASE/Ritonavir
An ECG should be performed prior to initiation of treatment. Patients with a QT interval ≥ 450 msec should not initiate treatment with INVIRASE/ritonavir.
Treatment-naïve patients initiating treatment with INVIRASE/ritonavir should receive a reduced starting dose of INVIRASE 500 mg twice daily with ritonavir 100 mg twice daily for the first 7 days of treatment followed by INVIRASE/ritonavir 1000/100 mg twice daily due to potential for an increased risk of PR and QT interval prolongation with the standard 1000/100 mg twice daily dose [see CLINICAL PHARMACOLOGY].
For patients with a baseline QT interval < 450 msec, an on-treatment ECG is recommended after approximately 10 days of therapy.
Discontinue INVIRASE/ritonavir in patients with a QT interval prolongation > 20 msec over pre-treatment.
Patients Requiring Treatment With Medications With The Potential To Increase The QT Interval And Concomitant INVIRASE/Ritonavir
Such combinations should only be used where no alternative therapy is available, and the potential benefits outweigh the potential risks. An ECG should be performed prior to initiation of the concomitant therapy, and patients with a QT interval > 450 msec should not initiate the concomitant therapy. If baseline QT interval < 450 msec, an on-treatment ECG should be performed after 3–4 days of therapy. For patients demonstrating a subsequent increase in QT interval by > 20 msec after commencing concomitant therapy, the physician should use best clinical judgment to discontinue either INVIRASE/ritonavir or the concomitant therapy or both.
A cardiology consult is recommended if drug discontinuation or interruption is being considered on the basis of ECG assessment.
Diabetes Mellitus/Hyperglycemia
New onset of diabetes mellitus, exacerbation of preexisting diabetes mellitus and hyperglycemia have been reported during postmarketing surveillance in HIV-1-infected patients receiving protease-inhibitor therapy. Some patients required either initiation or dose adjustments of insulin or oral hypoglycemic agents for the treatment of these events. In some cases, diabetic ketoacidosis has occurred. In those patients who discontinued protease-inhibitor therapy, hyperglycemia persisted in some cases. Because these events have been reported voluntarily during clinical practice, estimates of frequency cannot be made and a causal relationship between protease-inhibitor therapy and these events has not been established.
Hepatotoxicity
In patients with underlying hepatitis B or C, cirrhosis, chronic alcoholism or other underlying liver abnormalities, there have been reports of worsening of the underlying liver disease and development of portal hypertension after starting INVIRASE/ritonavir. Jaundice and exacerbation of chronic liver disease with grade 4 elevated liver function tests were also observed. No dosage adjustment is necessary for patients with mild or moderate hepatic impairment based on limited data [see CLINICAL PHARMACOLOGY]. INVIRASE/ritonavir is contraindicated in patients with severe hepatic impairment [see CONTRAINDICATIONS]. If a serious or severe toxicity occurs during treatment with INVIRASE/ritonavir, discontinue INVIRASE/ritonavir.
Hemophilia
There have been reports of spontaneous bleeding in patients with hemophilia A and B treated with protease inhibitors. In some patients, additional factor VIII was required. In the majority of reported cases, treatment with protease inhibitors was continued or restarted. A causal relationship between protease inhibitor therapy and these episodes has not been established.
Hyperlipidemia
Elevated cholesterol and/or triglyceride levels have been observed in some patients taking saquinavir in combination with ritonavir. Marked elevation in triglyceride levels is a risk factor for development of pancreatitis. Cholesterol and triglyceride levels should be monitored prior to initiating combination dosing regimen of INVIRASE/ritonavir, and at periodic intervals while on such therapy. In these patients, lipid disorders should be managed as clinically appropriate.
Lactose Intolerance
Each tablet contains lactose (monohydrate) 38.5 mg and each capsule contains lactose (anhydrous) 63.3 mg. INVIRASE is not recommended in patients with rare hereditary problems of galactose intolerance, the Lapp lactase deficiency or glucose-galactose malabsorption (autosomal recessive disorder).
Fat Redistribution
Redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement (buffalo hump), facial wasting, peripheral wasting, breast enlargement, and “cushingoid appearance” have been observed in patients receiving antiretroviral therapy. The mechanism and long-term consequences of these events are currently unknown. A causal relationship has not been established.
Immune Reconstitution Syndrome
Immune reconstitution syndrome has been reported in patients treated with combination antiretroviral therapy, including INVIRASE/ritonavir. During the initial phase of combination antiretroviral treatment, patients whose immune system responds may develop an inflammatory response to indolent or residual opportunistic infections (such as Mycobacterium avium infection, cytomegalovirus, Pneumocystis jiroveci pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment.
Autoimmune disorders (such as Graves’ disease, polymyositis, and Guillain-Barré syndrome) have also been reported to occur in the setting of immune reconstitution; however, the time to onset is more variable and can occur many months after initiation of treatment.
Resistance/Cross-resistance
Varying degrees of cross-resistance among HIV-1 protease inhibitors have been observed. Continued administration of INVIRASE/ritonavir therapy following loss of viral suppression may increase the likelihood of cross-resistance to other protease inhibitors [see Microbiology].
Patient Counseling Information
Advise the patient to read the FDA-approved patient labeling (Medication Guide).
Important Dosing Instructions
Advise patients that INVIRASE must be used in combination with ritonavir, which significantly inhibits saquinavir’s metabolism to provide increased plasma saquinavir levels.
Advise patients that INVIRASE administered with ritonavir should be taken within 2 hours after a meal [see CLINICAL PHARMACOLOGY]. When INVIRASE/ritonavir is taken without food, concentrations of saquinavir in the blood are substantially reduced and may result in no antiviral activity. Advise patients of the importance of taking their medication every day, as prescribed, to achieve maximum benefit. Patients should not alter the dose or discontinue therapy without consulting their physician. If a dose is missed, patients should take the next dose as soon as possible; however, the patient should not double the next dose.
Risk Of Serious Adverse Reactions Drug Interactions
INVIRASE/ritonavir may interact with many drugs; therefore, advise patients to report the use of any other prescription, nonprescription medication, or herbal products, particularly St. John’s wort [see CONTRAINDICATIONS, WARNINGS AND PRECAUTIONS, and DRUG INTERACTIONS].
PR And QT Interval Prolongation
Inform patients that INVIRASE/ritonavir may produce changes in the electrocardiogram (PR interval or QT interval prolongation). Advise patients to consult their health care provider if they are experiencing symptoms such as dizziness, lightheadedness, or palpitations [see WARNINGS AND PRECAUTIONS].
Diabetes Mellitus/Hyperglycemia
Inform patients that new onset of diabetes or exacerbation of pre-existing diabetes mellitus, and hyperglycemia have been reported during INVIRASE/ritonavir use. Advise patients to notify their healthcare provider if they develop signs and symptoms of diabetes [see WARNINGS AND PRECAUTIONS].
Hepatotoxicity
Inform patients with underlying liver abnormalities that there have been reports of worsening liver disease and development of portal hypertension with INVIRASE/ritonavir. Advise patients about the signs and symptoms of liver problems [see WARNINGS AND PRECAUTIONS]
Hyperlipidemia
Advise patients that treatment with INVIRASE/ritonavir can result in substantial increases in total cholesterol and triglycerides [see WARNINGS AND PRECAUTIONS]
Fat Redistribution
Inform patients that redistribution or accumulation of body fat may occur in patients receiving antiretroviral therapy, including INVIRASE/ritonavir, and that the cause and long-term health effects of these conditions are not known at this time [see WARNINGS AND PRECAUTIONS].
Immune Reconstitution Syndrome
Advise patients to inform their healthcare provider immediately of any symptoms of infection, as in some patients with advanced HIV infection (AIDS), signs and symptoms of inflammation from previous infections may occur soon after anti-HIV treatment is started [see WARNINGS AND PRECAUTIONS].
Pregnancy Exposure Registry
Advise patients that there is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to antiretrovirals during pregnancy [see Use In Specific Populations]. Lactation Instruct mothers with HIV-1 infection not to breastfeed because HIV-1 can be passed to the baby in breast milk [see Use In Specific Populations].
Nonclinical Toxicology
Carcinogenesis, Mutagenesis, Impairment Of Fertility
Carcinogenesis
Carcinogenicity studies found no indication of carcinogenic activity in rats and mice administered saquinavir for approximately 2 years. Because of limited bioavailability of saquinavir in animals, the plasma exposures (AUC values) in the respective species were approximately 29% (using rat) and 65% (using mouse) of those obtained in humans at the recommended clinical dose combined with ritonavir.
Mutagenesis
Mutagenicity and genotoxicity studies, with and without metabolic activation where appropriate, have shown that saquinavir has no mutagenic activity in vitro in either bacterial (Ames test) or mammalian cells (Chinese hamster lung V79/HPRT test). Saquinavir does not induce chromosomal damage in vivo in the mouse micronucleus assay or in vitro in human peripheral blood lymphocytes, and does not induce primary DNA damage in vitro in the unscheduled DNA synthesis test.
Impairment Of Fertility
No adverse effects were reported in fertility and reproductive performance study conducted in rats. Because of limited bioavailability of saquinavir in animals, the maximal plasma exposures achieved in rats were approximately 26% of those obtained in humans at the recommended clinical dose combined with ritonavir.
Use In Specific Populations
Pregnancy
Pregnancy Exposure Registry
There is a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to antiretrovirals during pregnancy. Healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263.
Risk Summary
Prospective pregnancy data from the APR are not sufficient to adequately assess a drug-associated risk of birth defects or fetal outcomes. Limited number of reports on the use of saquinavir during pregnancy has been submitted to the APR and the number of exposures to saquinavir is insufficient to make a risk assessment compared to a reference population. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. The estimated background rate for major birth defects is 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects Program (MACDP). The estimated rate of miscarriage is not reported in the APR. The estimated background rate of miscarriage in the U.S. general population is 15–20%.
In animal reproduction studies with saquinavir, no evidence of adverse developmental effects were observed at the highest achievable plasma exposures (AUC) in both rats and rabbits, resulting in exposures approximately 25% of those obtained in humans at the recommended human dose (RHD) combined with ritonavir. Saquinavir should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus (see Data).
Data
Human Data
Based on prospective reports to the APR following exposure to saquinavir-containing regimens, there were 7 birth defects reported in 183 first trimester exposures and 9 birth defects reported in 221 second and third trimester exposures. Insufficient numbers of pregnancies with exposure to saquinavir have been reported to the APR to calculate the prevalence (95% CI) or for a detailed assessment about the risk of saquinavir with regard to birth defects in this population. The background rate for major birth defects is 2.7% in a U.S. reference population of the MACDP. Prospective reports from the APR of overall major birth defects in pregnancies exposed to saquinavir are compared with the U.S. background major birth defect rate. Methodological limitations of the APR include the use of the 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.
Animal Data
In animal reproduction studies, no evidence of harm to the fetus was detected when saquinavir was administered orally to pregnant rats and rabbits twice-daily during the period of organogenesis at dose levels up to 1200 (rats) or 1000 (rabbits) mg/kg/day. However, because of limited bioavailability of saquinavir in animals and/or dosing limitations, plasma exposures (AUC) in these species were only 29% (rat) and 21% (rabbits) of those obtained in humans at the RHD combined with ritonavir. In a pre- and postnatal development study, saquinavir was administered orally to pregnant rats (up to 1600 mg/kg/day) from gestation day 15 to post-partum day 20. No adverse effects were observed in the offspring exposed daily from before birth through lactation at maternal exposures (AUC) approximately 27% of those obtained in humans at the RHD combined with ritonavir.
Lactation
The Centers for Disease Control and Prevention recommends that HIV-infected mothers in the United States not breastfeed their infants to avoid risking postnatal transmission of HIV-1.
There are no data available regarding the presence of saquinavir in human milk, the effects on the breastfed infant, or the effects on milk production.
Because of the potential for (1) HIV-1 transmission (in HIV-negative infants), (2) developing viral resistance (in HIV-positive infants) and (3) adverse reactions in breastfed infants similar to those seen in adults, instruct mothers not to breastfeed if they are receiving INVIRASE.
Pediatric Use
The safety and activity of INVIRASE have been evaluated in 68 pediatric subjects 4 months to less than 16 years of age treated with saquinavir mesylate capsules (hard gel) combined with either ritonavir or with lopinavir/ritonavir in two clinical trials. Data from the NV20911 trial demonstrated that saquinavir mesylate capsules (hard gel) combined with low dose ritonavir provided plasma levels of saquinavir that were significantly higher than those historically observed in adults at the approved dose [see CLINICAL PHARMACOLOGY]. The HIVNAT 017 trial provided long term 96-week activity and safety data; however, pharmacokinetic data from this study could not be validated.
HIVNAT 017 was an open-label, single-arm trial at two centers in Thailand that evaluated the use of saquinavir mesylate capsules (hard gel) (50 mg per kg twice daily given as 200-mg capsules) with lopinavir/ritonavir (230/57.5 mg/m2 twice daily) for 96 weeks. Fifty subjects 4 years to less than 16 years of age were enrolled. In this trial population, treatment resulted in HIV-1 RNA < 400 copies/mL at week 96 in 78% of subjects (HIV-1 RNA < 50 copies per mL at week 96 in 66%). Mean CD4 lymphocyte percentage increased from 8% at screening to 22% at week 96.
NV20911 was an open-label, multinational trial that evaluated the pharmacokinetics, safety, and activity of saquinavir mesylate capsules (hard gel) (50 mg per kg twice daily as 200-mg capsules, up to the adult dose of 1,000 mg twice daily) and ritonavir oral solution plus ≥2 background ARVs. Eighteen subjects 4 months to less than 6 years of age were enrolled. Treatment with INVIRASE/ritonavir resulted in HIV-1 RNA < 400 copies per mL at week 48 in 72% of subjects (HIV-1 RNA < 50 copies per mL at week 48 in 61%). The percentage of subjects with HIV-1 RNA < 50 copies per mL at week 48 was 61%. Mean CD4 lymphocyte percentage increased from 29% at screening to 34% at week 48.
Steady-state saquinavir exposures observed in pediatric trials were substantially higher than historical data in adults where dose- and exposure-dependent QTc and PR prolongation were observed [see WARNINGS AND PRECAUTIONS, CLINICAL PHARMACOLOGY]. Although electrocardiogram abnormalities were not reported in these pediatric trials, the trials were small and not designed to evaluate QT or PR intervals. Modeling and simulation assessment of pharmacokinetic/pharmacodynamic relationships in pediatric subjects suggest that reducing the INVIRASE dose to minimize risk of QT prolongation is likely to reduce antiviral efficacy. In addition, no clinical efficacy data are available at INVIRASE doses less than 50 mg per kg in pediatric subjects. Therefore, pediatric dose recommendations that are both reliably effective and below thresholds of concern with respect to QT and PR prolongation could not be determined.
Geriatric Use
Clinical trials of INVIRASE did not include sufficient numbers of subjects aged 65 and over to determine whether they respond differently from younger subjects. In general, dosing INVIRASE/ritonavir in elderly patients should be undertaken with caution keeping in mind the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy.
Impaired Renal Function
Renal clearance is a minor elimination pathway; the principal route of excretion for saquinavir is by hepatic metabolism. Therefore, no initial dose adjustment is necessary for patients with renal impairment. However, patients with severe renal impairment or end-stage renal disease (ESRD) have not been studied, and caution should be exercised when prescribing INVIRASE/ritonavir in this population.
Impaired Hepatic Function
No dosage adjustment is necessary for HIV-1-infected patients with mild or moderate hepatic impairment based on limited data. In patients with underlying hepatitis B or C, cirrhosis, chronic alcoholism and/or other underlying liver abnormalities, there have been reports of worsening liver disease [see CLINICAL PHARMACOLOGY]. INVIRASE/ritonavir is contraindicated in patients with severe hepatic impairment [see CONTRAINDICATIONS].