Atazanavir (Adverse effects)

Atazanavir is a direct-acting antiviral that is often used together with other medications, such as ritonavir or cobicistat, to treat human immunodeficiency virus (HIV) infection in adults and children who are at least 3 months old and weigh at least 10 kg. Atazanavir belongs to a class of drugs known as protease inhibitors. Atazanavir works by lowering the amount of HIV in the blood. Although atazanavir does not cure HIV, it can reduce the chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking this drug can lower the risk of passing the HIV virus to other people.

Atazanavir is sometimes used to prevent infection in health care workers or others who were accidentally exposed to HIV.

Currently, in 2020, it is being studied for the treatment of the SARS-CoV-2 coronavirus, but the effectiveness studies are still not conclusive.

ACTION MECHANISM

Atazanavir works by inhibiting the HIV protease, preventing the formation of mature virions in cells that are already infected and thus making it difficult for other cells to infect.

CONTRAINDICATIONS

Hypersensitivity to atazanavir.

Contraindicated in patients with severe liver failure. Caution in patients with mild hepatic impairment.

Contraindicated concomitantly with: simvastatin, lovastatin, rifampicin, sildenafil for the treatment of pulmonary arterial hypertension, CYP3A4 substrates with a narrow therapeutic margin (eg: quetiapine, alfuzosin, astemizole, terfenadine, cisapride, pimozide, quinidine, bepridil, oral midazolam and ergot alkaloids, especially ergotamine, dihydroergotamine, ergonovine, methylergonovine), St. John's wort.

PHARMACOLOGIC INTERACTIONS

Monitor for possible adverse reactions if atazanavir is being administered together with: tenofovir, disoproxil, irinotecan.

Caution with: clarithromycin; ketoconazole and itraconazole (not advisable in high doses greater than 200 mg/day); carbamazepine, lamotrigine, phenytoin and phenobarbital (monitor and adjust dose); pravastatin and fluvastatin; parenteral midazolam. Monitor INR (or prothrombin time) if you are taking warfarin.

Azatanavir increases the concentration of: systemic amiodarone and lidocaine (caution and concentration monitoring); immunosuppressants (cyclosporine, tacrolimus, sirolimus); rifabutin, buprenorphine and norbuprenorphine (control cognitive effects and sedation, consider reducing dose); diltiazem (reduce initial dose to 50%); verapamil.

SIDE EFFECTS

Headache, eye jaundice, vomiting, diarrhea, abdominal pain, nausea, dyspepsia, jaundice; itching, fatigue; increased levels of total bilirubin, increased levels of liver enzymes in plasma CK, ALT, AST and lipase.

Neutrophils number decrease.

Depression, fever, difficulty falling asleep, rashes, pain or numbness in the hands or feet, muscle aches.

Other more serious side effects may include: irregular heartbeat, vision defects, pain or burning when urinating, blood in the urine, swelling in the extremities, erections lasting more than 4 hours, blistering or peeling of the skin, red eyes or inflamed eyes, canker sores in the mouth, swelling of the face or neck, very severe rashes.

BRAND NAMES

• Reyataz®
• Evotaz® (contiene Atazanavir, Cobicistat)