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Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice.
Brand Name
Atazanavir
Generic Name
Atazanavir
Active Ingredient
AtazanavirCategory
Cytochrome P450 3A Inhibitor [EPC]
Salt Form
Sulfate
Variants
6
References used for this content
This page is for informational purposes only and does not replace medical advice. Before using any prescription or over-the-counter medication for Atazanavir, you must consult a qualified healthcare professional.
| 200 mg/1 | CAPSULE | ORAL | 31722-654 |
| 300 mg/1 | CAPSULE | ORAL | 31722-655 |
| 150 mg/1 | CAPSULE | ORAL | 42385-920 |
Detailed information about Atazanavir
Atazanavir is a potent azapeptide HIV-1 protease inhibitor used in combination with other antiretroviral agents to manage HIV-1 infection by preventing viral maturation.
The standard dosage of atazanavir depends on whether the patient has taken HIV medications before and whether it is being 'boosted' by another drug. According to the Department of Health and Human Services (HHS) guidelines:
Pediatric dosing is strictly based on body weight. For children at least 3 months of age and weighing at least 5 kg:
Healthcare providers will calculate the exact milligram-per-kilogram dose to ensure safety and efficacy.
For patients with kidney disease, atazanavir usually does not require a dose adjustment. However, for treatment-experienced patients with end-stage renal disease (ESRD) undergoing hemodialysis, atazanavir should not be used because it may not reach effective levels in the blood.
Atazanavir is processed by the liver. Patients with moderate hepatic impairment (Child-Pugh Class B) should have their dose reduced (e.g., 300 mg once daily without ritonavir). It is generally not recommended for patients with severe hepatic impairment (Child-Pugh Class C). Boosted atazanavir (with ritonavir) has not been sufficiently studied in patients with severe liver disease.
Clinical studies did not include enough patients over 65 to determine if they respond differently. However, because older adults are more likely to have decreased liver, kidney, or heart function, healthcare providers typically start at the lower end of the dosing range and monitor closely.
If you miss a dose of atazanavir, take it as soon as you remember with food. However, if it is almost time for your next dose (within 6 hours of the next scheduled dose), skip the missed dose and continue with your regular schedule. Do not 'double up' or take two doses at once to make up for a missed one. Frequent missed doses can lead to drug resistance, making the HIV harder to treat.
Symptoms of an atazanavir overdose may include severe jaundice (yellowing of the skin/eyes) or heart rhythm disturbances (PR interval prolongation). If an overdose is suspected, contact a Poison Control Center or seek emergency medical attention immediately. There is no specific antidote for atazanavir; treatment involves supportive care and monitoring of vital signs and ECG.
> Important: Follow your healthcare provider's dosing instructions exactly. Do not adjust your dose or stop taking the medication without medical guidance, as this can lead to treatment failure.
Atazanavir is generally well-tolerated, but some side effects are very common due to the drug's mechanism of action.
Atazanavir is a potent medication that requires careful clinical management. Patients must be aware that while atazanavir reduces the viral load, it does not prevent the transmission of HIV to others through sexual contact or blood contamination. Safe sex practices and needle-sharing precautions must still be followed. Additionally, atazanavir's efficacy is highly dependent on adherence; missing doses can lead to the development of drug-resistant HIV strains.
No FDA black box warnings for Atazanavir. However, it is important to note that many drugs used in combination with atazanavir (like certain boosters) may have their own specific warnings.
Atazanavir is a potent inhibitor of the CYP3A4 enzyme, meaning it can cause other drugs to build up to toxic levels in the body. The following drugs must NEVER be used with atazanavir:
Atazanavir is strictly contraindicated in several specific scenarios where the risk of use clearly outweighs any potential benefit:
Atazanavir is classified as a 'Preferred' protease inhibitor for use in pregnant individuals living with HIV, according to the HHS guidelines.
In the United States and other regions where safe infant formula and clean water are available, breastfeeding is generally not recommended for individuals with HIV to avoid the risk of postnatal transmission of the virus to the infant. Additionally, atazanavir is excreted in human milk. The effects of the drug on the nursing infant are not fully known.
Atazanavir is an azapeptide HIV-1 protease inhibitor. It selectively inhibits the virus-specific processing of viral Gag and Gag-Pol polyproteins in HIV-1 infected cells. It binds to the active site of the protease enzyme with high affinity (Ki of 2.66 nM). By preventing the cleavage of these polyproteins, atazanavir ensures that the resulting viral particles are immature and incapable of infecting other cells. It is active against a broad range of HIV-1 isolates but has limited activity against HIV-2.
The primary pharmacodynamic effect of atazanavir is the reduction of plasma HIV-1 RNA levels. The relationship between atazanavir plasma concentration and antiviral response is well-established. However, at higher concentrations, atazanavir also inhibits the UGT1A1 enzyme, which is responsible for the glucuronidation of bilirubin, leading to the characteristic increase in indirect bilirubin seen in patients.
| Parameter | Value |
|---|---|
| Bioavailability | ~60-68% (with food) |
Common questions about Atazanavir
Atazanavir is a prescription antiretroviral medication used in combination with other drugs to treat Human Immunodeficiency Virus Type 1 (HIV-1) infection. It belongs to a class of drugs called protease inhibitors, which work by blocking the enzyme the virus needs to mature and multiply. By reducing the amount of HIV in the body, atazanavir helps the immune system stay stronger and reduces the risk of AIDS-related illnesses. It is approved for use in both adults and children who are at least 3 months old. It is important to remember that while it manages the infection, it is not a cure for HIV.
The most frequently reported side effect of atazanavir is hyperbilirubinemia, which is an increase in bilirubin levels in the blood that can cause yellowing of the skin or eyes (jaundice). Other common side effects include nausea, headache, diarrhea, and stomach pain. Most of these symptoms are mild and may improve as your body adjusts to the medication. However, if jaundice becomes severe or if you develop a rash, you should contact your healthcare provider immediately. Unlike some other HIV drugs, atazanavir is less likely to cause significant increases in cholesterol or body fat changes.
There is no known direct interaction between atazanavir and alcohol that would make the drug ineffective. However, both alcohol and atazanavir are processed by the liver, so excessive drinking could potentially increase the strain on your liver function. Furthermore, alcohol can sometimes lead to missed doses, which is dangerous when treating HIV because it can lead to drug resistance. It is generally best to consume alcohol only in moderation and to discuss your habits with your doctor. Always prioritize taking your medication at the same time every day, regardless of alcohol consumption.
Atazanavir is considered one of the 'preferred' protease inhibitors for use during pregnancy to prevent mother-to-child transmission of HIV. Clinical data have shown that it is generally safe for both the mother and the developing fetus. However, because the body processes the drug faster during pregnancy, it must be taken with a 'booster' like ritonavir to ensure levels remain high enough to control the virus. Pregnant women should be monitored for jaundice, and the newborn should also be checked for elevated bilirubin levels after birth. Always consult your obstetrician and HIV specialist if you are pregnant or planning to become pregnant.
Atazanavir begins working to inhibit the HIV protease enzyme shortly after the first dose is absorbed into the bloodstream. However, it may take several weeks or even months of consistent use to see a significant drop in your viral load (the amount of virus in your blood) and an increase in your CD4 cell count. Most patients achieve an 'undetectable' viral load within 3 to 6 months of starting a full antiretroviral regimen. Success depends heavily on taking the medication every single day as prescribed. Your doctor will perform regular blood tests to monitor how well the drug is working for you.
No, you should never stop taking atazanavir or any other HIV medication without first talking to your healthcare provider. Abruptly stopping the medication allows the HIV virus to begin replicating again very quickly. This can lead to a 'viral rebound' and, more importantly, can cause the virus to develop resistance to atazanavir and other similar drugs. Once resistance develops, those medications may never work for you again. If you are experiencing difficult side effects, your doctor can help you switch to a different medication safely without risking your long-term health.
If you miss a dose of atazanavir, take it with food as soon as you remember. However, if you are within 6 hours of your next scheduled dose, you should skip the missed dose and simply take your next dose at the regular time. Do not take two doses at once to make up for the one you missed, as this can increase the risk of side effects like jaundice or heart rhythm changes. Consistency is the most important part of HIV treatment. If you find yourself frequently forgetting doses, talk to your doctor about tools or different regimens that might be easier for you to follow.
Weight gain is not a primary side effect of atazanavir itself, but many patients starting HIV therapy experience 'return-to-health' weight gain as their immune system recovers and their body begins to function more normally. Some protease inhibitors are associated with lipodystrophy, which is a redistribution of body fat (such as increased fat in the abdomen or back of the neck), but atazanavir is generally considered to have a lower risk of this compared to older drugs in its class. If you notice significant or unusual changes in your weight or body shape, discuss them with your healthcare provider to determine the cause.
Atazanavir has many significant drug interactions, so it must be used cautiously with other medications. It is especially sensitive to drugs that reduce stomach acid, such as proton pump inhibitors (like omeprazole) and antacids, which can prevent atazanavir from being absorbed. It also interacts with certain cholesterol medications, herbal supplements like St. John's Wort, and some blood thinners. You must provide your doctor and pharmacist with a complete list of every medication, vitamin, and supplement you take. They will check for 'contraindications' to ensure your HIV treatment remains effective and safe.
Yes, atazanavir is available as a generic medication in several strengths (150 mg, 200 mg, and 300 mg capsules). The generic version contains the same active ingredient and meets the same FDA standards for safety, purity, and effectiveness as the brand-name version, Reyataz. Using the generic version can significantly reduce the cost of HIV treatment for many patients. If you are currently taking the brand-name drug, you can ask your pharmacist or doctor if a generic equivalent is available and appropriate for your specific prescription. Most insurance plans cover the generic version of atazanavir.
Other drugs with the same active ingredient (Atazanavir)
> Warning: Stop taking Atazanavir and call your doctor immediately if you experience any of these serious symptoms.
With prolonged use, patients may experience metabolic changes. These include increased cholesterol and triglyceride levels (hyperlipidemia), which may increase the risk of cardiovascular disease. Chronic use has also been linked to a slight increase in the risk of chronic kidney disease (CKD) in some populations. Regular blood tests to monitor kidney function, liver enzymes, and lipid levels are essential for long-term safety.
As of 2024, atazanavir does not carry an FDA Black Box Warning. However, it does have significant 'Warnings and Precautions' regarding drug interactions and cardiac conduction abnormalities that are treated with similar clinical gravity. Specifically, the risk of PR interval prolongation is a major focus for clinicians when prescribing this drug to patients with pre-existing heart conditions.
Report any unusual symptoms to your healthcare provider immediately. Most side effects can be managed with supportive care or by adjusting the treatment regimen.
To ensure the safe use of atazanavir, healthcare providers will require regular laboratory monitoring:
Atazanavir generally does not cause significant impairment. However, if you experience dizziness or lightheadedness (which can occur with heart rhythm changes or as a general side effect), you should avoid driving or operating heavy machinery until the symptoms resolve.
There is no direct contraindication between atazanavir and alcohol. However, excessive alcohol consumption can strain the liver, which is already processing the medication. Furthermore, alcohol can interfere with medication adherence. Patients are advised to discuss their alcohol intake with their doctor.
Never stop taking atazanavir without consulting your healthcare provider. Abruptly stopping HIV medication allows the virus to replicate rapidly, which can lead to a 'rebound' in viral load and the development of drug resistance. If the drug must be stopped due to a severe side effect, your doctor will provide a plan to switch to an alternative antiretroviral regimen immediately.
> Important: Discuss all your medical conditions, especially heart, liver, or kidney problems, with your healthcare provider before starting Atazanavir.
Atazanavir primarily affects bilirubin tests. It causes an increase in unconjugated (indirect) bilirubin. This is a predictable laboratory finding and does not usually indicate liver injury, but it must be distinguished from other causes of jaundice. It does not typically interfere with standard urine drug screens.
For each major interaction, the mechanism is usually the inhibition of the CYP3A4 enzyme by atazanavir, which prevents the second drug from being cleared from the body. This leads to increased toxicity. Conversely, drugs like rifampin induce the enzyme, causing atazanavir to be cleared too quickly, leading to reduced efficacy.
> Important: Tell your doctor about ALL medications, supplements, and herbal products you are taking, as the list of interactions for Atazanavir is one of the most extensive in clinical medicine.
These conditions require a careful risk-benefit analysis by a specialist:
While atazanavir is an azapeptide and not a sulfonamide, patients who have had severe allergic reactions to other protease inhibitors should be monitored closely. There is no evidence of direct cross-reactivity with sulfa drugs, but a history of multiple drug allergies should always be disclosed to the prescribing physician.
> Important: Your healthcare provider will evaluate your complete medical history, including heart and liver health, before prescribing Atazanavir.
Atazanavir is FDA-approved for pediatric patients from 3 months of age weighing at least 5 kg.
Patients aged 65 and older may have a higher prevalence of decreased hepatic, renal, or cardiac function.
> Important: Special populations require individualized medical assessment and more frequent laboratory monitoring to ensure safety.
| Protein Binding | 86% |
| Half-life | 7 hours (boosted) |
| Tmax | 2.5 hours |
| Metabolism | Hepatic (CYP3A4) |
| Excretion | Fecal 79%, Renal 13% |
Atazanavir belongs to the Protease Inhibitor (PI) class of antiretrovirals. Within this class, it is distinguished by its 'azapeptide' structure. It is often compared to other PIs like darunavir or lopinavir. Unlike earlier PIs, atazanavir has a more neutral effect on metabolic parameters like insulin resistance and lipid levels, although it carries a unique risk of hyperbilirubinemia.