WARNINGS
Included as part of the "PRECAUTIONS" Section
PRECAUTIONS
Risk Of Serious Adverse Reactions Due To Drug Interactions
Initiation of NORVIR, a CYP3A inhibitor, in patients receiving medications metabolized by CYP3A or
initiation of medications metabolized by CYP3A in patients already receiving NORVIR, may increase
plasma concentrations of medications metabolized by CYP3A. Initiation of medications that inhibit or
induce CYP3A may increase or decrease concentrations of NORVIR, 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 NORVIR.
- Loss of therapeutic effect of NORVIR and possible development of resistance.
When co-administering NORVIR with other protease inhibitors, see the full prescribing information for
that protease inhibitor including important Warnings and Precautions.
See Table 4 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 NORVIR therapy; review concomitant medications during NORVIR
therapy, and monitor for the adverse reactions associated with the concomitant medications [see CONTRAINDICATIONS and DRUG INTERACTIONS].
Hepatotoxicity
Hepatic transaminase elevations exceeding 5 times the upper limit of normal, clinical hepatitis, and
jaundice have occurred in patients receiving NORVIR alone or in combination with other antiretroviral
drugs (see Table 3). There may be an increased risk for transaminase elevations in patients with
underlying hepatitis B or C. Therefore, caution should be exercised when administering NORVIR to
patients with pre-existing liver diseases, liver enzyme abnormalities, or hepatitis. Increased AST/ALT
monitoring should be considered in these patients, especially during the first three months of NORVIR
treatment [see Use In Specific Populations].
There have been postmarketing reports of hepatic dysfunction, including some fatalities. These have
generally occurred in patients taking multiple concomitant medications and/or with advanced AIDS.
Pancreatitis
Pancreatitis has been observed in patients receiving NORVIR therapy, including those who developed
hypertriglyceridemia. In some cases fatalities have been observed. Patients with advanced HIV-1
disease may be at increased risk of elevated triglycerides and pancreatitis [see Immune Reconstitution Syndrome]. Pancreatitis should be considered if clinical symptoms (nausea, vomiting, abdominal pain) or
abnormalities in laboratory values (such as increased serum lipase or amylase values) suggestive of
pancreatitis should occur. Patients who exhibit these signs or symptoms should be evaluated and
NORVIR therapy should be discontinued if a diagnosis of pancreatitis is made.
Allergic Reactions /Hypersensitivity
Allergic reactions including urticaria, mild skin eruptions, bronchospasm, and angioedema have been
reported. Cases of anaphylaxis, toxic epidermal necrolysis (TEN), and Stevens-Johnson syndrome have
also been reported. Discontinue treatment if severe reactions develop.
PR Interval Prolongation
Ritonavir prolongs the PR interval in some patients. Post marketing cases of second or third degree
atrioventricular block have been reported in patients.
NORVIR should be used with caution in patients with underlying structural heart disease, preexisting
conduction system abnormalities, ischemic heart disease, cardiomyopathies, as these patients may be at
increased risk for developing cardiac conduction abnormalities.
The impact on the PR interval of co-administration of 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, co-administration of ritonavir with these drugs should be undertaken with
caution, particularly with those drugs metabolized by CYP3A. Clinical monitoring is recommended [see DRUG INTERACTIONS, and CLINICAL PHARMACOLOGY].
Lipid Disorders
Treatment with NORVIR therapy alone or in combination with saquinavir has resulted in substantial
increases in the concentration of total cholesterol and triglycerides [see ADVERSE REACTIONS].
Triglyceride and cholesterol testing should be performed prior to initiating NORVIR therapy and at
periodic intervals during therapy. Lipid disorders should be managed as clinically appropriate, taking
into account any potential drug-drug interactions with NORVIR and HMG CoA reductase inhibitors [see CONTRAINDICATIONS, and DRUG INTERACTIONS].
Diabetes Mellitus /Hyperglycemia
New onset diabetes mellitus, exacerbation of pre-existing 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 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.
Consider monitoring for hyperglycemia, new onset diabetes mellitus, or an exacerbation of diabetes
mellitus in patients treated with NORVIR.
Immune Reconstitution Syndrome
Immune reconstitution syndrome has been reported in HIV-1 infected patients treated with combination
antiretroviral therapy, including NORVIR. 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.
Fat Redistribution
Redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement
(buffalo hump), peripheral wasting, facial 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.
Patients With Hemophilia
There have been reports of increased bleeding, including spontaneous skin hematomas and
hemarthrosis, in patients with hemophilia type A and B treated with protease inhibitors. In some patients
additional factor VIII was given. In more than half of the reported cases, treatment with protease
inhibitors was continued or reintroduced. A causal relationship between protease inhibitor therapy and
these events has not been established.
Resistance/Cross -resistance
Varying degrees of cross-resistance among protease inhibitors have been observed. Continued
administration of ritonavir 600 mg twice daily following loss of viral suppression may increase the
likelihood of cross-resistance to other protease inhibitors [see Microbiology].
Laboratory Tests
Ritonavir has been shown to increase triglycerides, cholesterol, SGOT (AST), SGPT (ALT), GGT,
CPK, and uric acid. Appropriate laboratory testing should be performed prior to initiating NORVIR
therapy and at periodic intervals or if any clinical signs or symptoms occur during therapy.
Patient Conseling Information
Advise the patient to read the FDA-approved patient labeling (PATIENT INFORMATION).
General Information
- Advise patients and caregivers to pay special attention to accurate administration of their dose to
minimize the risk of accidental overdose or underdose of NORVIR.
- Advise caregivers to inform their healthcare provider if their children’s weight changes in order to
make sure that the child’s NORVIR dose is adjusted as needed.
- Advise patients to take NORVIR with meals.
- For adult patients taking NORVIR capsules, the maximum dose of 600 mg twice daily by mouth with
meals should not be exceeded.
- Advise patients to remain under the care of a physician while using NORVIR and to take NORVIR
and other concomitant antiretroviral therapy every day as prescribed. NORVIR must always be used
in combination with other antiretroviral drugs. Advise patients not to alter the dose or discontinue
therapy without consulting with their healthcare provider. If a dose of NORVIR is missed patients
should take the dose as soon as possible and then return to their normal schedule. However, if a
dose is skipped the patient should not double the next dose.
- Continued NORVIR therapy at a dose of 600 mg twice daily following loss of viral suppression
may increase the likelihood of cross-resistance to other protease inhibitors.
- NORVIR is not a cure for HIV-1 infection and patients may continue to experience illnesses
associated with HIV-1 infection, including opportunistic infections. Patients should remain under the
care of a physician when using NORVIR.
Drug Interactions
- NORVIR may interact with some drugs; therefore, patients should be advised to report to their
doctor the use of any other prescription, non-prescription medication or herbal products,
particularly St. John's Wort.
- Instruct patients receiving combined hormonal contraception to use an effective alternative
contraceptive method or an additional barrier method during therapy with NORVIR because
hormonal levels may decrease [see DRUG INTERACTIONS, Use In Specific Populations].
Hepatotoxicity
Pre-existing liver disease including Hepatitis B or C can worsen with use of NORVIR. This can be
seen as worsening of transaminase elevations or hepatic decompensation. Advise patients that their liver
function tests will need to be monitored closely especially during the first several months of NORVIR
treatment and that they should notify their healthcare provider if they develop the signs and symptoms of
worsening liver disease including loss of appetite, abdominal pain, jaundice, and itchy skin [see WARNINGS AND PRECAUTIONS].
Pancreatitis
Pancreatitis, including some fatalities, has been observed in patients receiving NORVIR therapy.
Advise patients to notify their healthcare provider of signs and symptoms (nausea, vomiting, and
abdominal pain) that might be suggestive of pancreatitis [see WARNINGS AND PRECAUTIONS].
Allergic Reactions/Hypersensitivity
Skin rashes ranging in severity from mild to Stevens-Johnson syndrome have been reported in patients
receiving NORVIR. Advise patients to contact their healthcare provider if they develop a rash while
taking NORVIR [see WARNINGS AND PRECAUTIONS].
PR Interval Prolongation
NORVIR may produce changes in the electrocardiogram (e.g., PR prolongation). Advise patients to
consult their healthcare provider if they experience symptoms such as dizziness, lightheadedness,
abnormal heart rhythm or loss of consciousness [see WARNINGS AND PRECAUTIONS].
Lipid Disorders
Advise patients that treatment with NORVIR therapy can result in substantial increases in the
concentration of total cholesterol and triglycerides [see WARNINGS AND PRECAUTIONS].
Diabetes Mellitus/Hyperglycemia
Advise patients that new onset of diabetes or exacerbation of pre-existing diabetes mellitus, and
hyperglycemia have been reported and to notify their healthcare provider if they develop the signs and
symptoms of diabetes mellitus including frequent urination, excessive thirst, extreme hunger or unusual
weight loss and/or an increased blood sugar while on NORVIR as they may require a change in their
diabetes treatment or new treatment [see WARNINGS AND PRECAUTIONS].
Immune Reconstitution Syndrome
Advise patients that immune reconstitution syndrome has been reported in HIV-1 infected patients
treated with combination antiretroviral therapy, including NORVIR [see WARNINGS AND PRECAUTIONS].
Fat Redistribution
Advise patients that redistribution or accumulation of body fat may occur in patients receiving
antiretroviral therapy and that the cause and long term health effects of these conditions are not known at
this time [see WARNINGS AND PRECAUTIONS].
Patients With Hemophilia
Advise patients with hemophilia that they may experience increased bleeding when treated with
protease inhibitors such as NORVIR [see WARNINGS AND PRECAUTIONS].
Pregnancy Exposure Registry
Inform patients that there is an antiretroviral pregnancy registry that monitors fetal outcomes of pregnant
women exposed to NORVIR [see Use In Specific Populations].
Lactation
Instruct women 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 in mice and rats have been carried out on ritonavir. In male mice, at levels of 50,
100 or 200 mg per kg per day, there was a dose dependent increase in the incidence of both adenomas
and combined adenomas and carcinomas in the liver. Based on AUC measurements, the exposure at the
high dose was approximately 0.3-fold for males that of the exposure in humans with the recommended
therapeutic dose (600 mg twice-daily). There were no carcinogenic effects seen in females at the
dosages tested. The exposure at the high dose was approximately 0.6-fold for the females that of the
exposure in humans. In rats dosed at levels of 7, 15 or 30 mg per kg per day there were no carcinogenic
effects. In this study, the exposure at the high dose was approximately 6% that of the exposure in
humans with the recommended therapeutic dose. Based on the exposures achieved in the animal studies,
the significance of the observed effects is not known.
Mutagenesis
Ritonavir was found to be negative for mutagenic or clastogenic activity in a battery of in vitro and in
vivo assays including the Ames bacterial reverse mutation assay using S. typhimurium and E. coli, the
mouse lymphoma assay, the mouse micronucleus test and chromosomal aberration assays in human
lymphocytes.
Impairment Of Fertility
Ritonavir produced no effects on fertility in rats at drug exposures approximately 40% (male) and 60%
(female) of that achieved with the proposed therapeutic dose. Higher dosages were not feasible due to
hepatic toxicity.
Use In Specific Populations
When co-administering NORVIR with other protease inhibitors, see the full prescribing information for
the co-administered protease inhibitor including important information for use in special populations.
Pregnancy
Pregnancy Exposure Registry
There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to
NORVIR 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 Antiretroviral Pregnancy Registry (APR) are not sufficient to
adequately assess the risk of birth defects or miscarriage. Available data from the APR show no
difference in the rate of overall birth defects for ritonavir compared to the background rate for major
birth defects of 2.7% in the U.S. reference population of the Metropolitan Atlanta Congenital Defects
Program (MACDP) [see Data ].
In animal reproduction studies, no evidence of adverse developmental outcomes was observed with oral
administration of ritonavir to pregnant rats and rabbits. During organogenesis in the rat and rabbit,
systemic exposure (AUC) was approximately 1/3 lower than human exposure at the recommended daily
dose. In the rat pre- and post-natal developmental study, maternal systemic exposure to ritonavir was
approximately 1/2 of the exposure in humans at the recommended daily dose, based on a body surface
area conversion factor [see Data].
The background risk of major birth defects and miscarriage for the indicated population is unknown. All
pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general
population, the estimated background risk of major birth defects and miscarriage in clinically
recognized pregnancies is 2-4% and 15-20%, respectively.
Data
Human Data
Based on prospective reports to the APR of approximately 6100 live births following exposure to
ritonavir-containing regimens (including over 2800 live births exposed in the first trimester and over
3200 live births exposed in the second and third trimesters), there was no difference in the rate of
overall birth defects for ritonavir 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 2.3% (95% CI:
1.7%-2.9%) following first-trimester exposure to ritonavir-containing regimens and 2.9% (95% CI:
2.3%-3.5%) following second and third trimester exposure to ritonavir-containing regimens.
While placental transfer of ritonavir and fetal ritonavir concentrations are generally low, detectable
levels have been observed in cord blood samples and neonate hair.
Animal Data
Ritonavir was administered orally to pregnant rats (at 0, 15, 35, and 75 mg/kg/day), and rabbits (at 0, 25,
50, and 110 mg/kg/day) during organogenesis (on gestation days 6 through 17 and 6 through 19,
respectively). No evidence of teratogenicity due to ritonavir was observed in rats and rabbits at doses
producing systemic exposures (AUC) equivalent to approximately 1/3 lower than human exposure at the
recommended daily dose. Developmental toxicity observed in rats (early resorptions, decreased fetal
body weight and ossification delays and developmental variations) occurred at a maternally toxic dose at
an exposure equivalent to approximately 1/3 lower than human exposure at the recommended daily dose.
A slight increase in the incidence of cryptorchidism was also noted in rats (at a maternally toxic dose) at
an exposure approximately 1/5 lower than human exposure at the recommended daily dose.
Developmental toxicity was observed in rabbits (resorptions, decreased litter size and decreased fetal
weights) at maternally toxic dosage equivalent to 1.8 times higher than the recommended daily dose,
based on a body surface area conversion factor. In pre-and postnatal development study in rats, ritonavir
was administered at doses of 0, 15, 35, and 60 mg/kg/day from gestation day 6 through postnatal day 20.
At doses of 60 mg/kg/day, no developmental toxicity was noted with ritonavir dosage equivalent to 1/2
of the recommended daily dose, based on a body surface area conversion factor.
Lactation
Risk Summary
The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breastfeed
their infants to avoid risking postnatal transmission of HIV.
Limited published data reports that ritonavir is present in human milk.
There is no information on the effects of ritonavir on the breastfed infant or the effects of the drug on
milk production. Because of the potential for (1) HIV transmission (in HIV-negative infants), (2)
developing viral resistance (in HIV-positive infants) and (3) serious adverse reactions in a breastfed
infant, instruct mothers not to breastfeed if they are receiving NORVIR.
Females And Males Of Reproductive Potential
Contraception
Use of NORVIR may reduce the efficacy of combined hormonal contraceptives. Advise patients using
combined hormonal contraceptives to use an effective alternative contraceptive method or an additional
barrier method of contraception [see DRUG INTERACTIONS].
Pediatric Use
In HIV-1 infected patients age greater than 1 month to 21 years, the antiviral activity and adverse event
profile seen during clinical trials and through postmarketing experience were similar to that for adult
patients.
Geriatric Use
Clinical studies of NORVIR did not include sufficient numbers of subjects aged 65 and over to
determine whether they respond differently from younger subjects. In general, dose selection for an
elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the
greater frequency of decreased hepatic, renal or cardiac function, and of concomitant disease or other
drug therapy.
Hepatic Impairment
No dose adjustment of ritonavir is necessary for patients with either mild (Child-Pugh Class A) or
moderate (Child-Pugh Class B) hepatic impairment. No pharmacokinetic or safety data are available
regarding the use of ritonavir in subjects with severe hepatic impairment (Child-Pugh Class C),
therefore, ritonavir is not recommended for use in patients with severe hepatic impairment [see WARNINGS AND PRECAUTIONS, and CLINICAL PHARMACOLOGY].