Atavir

Indications

Atazanavir is an antiretroviral medicine used, together with other HIV medicines, to treat HIV-1 infection in adults and children. It does not cure HIV, but it keeps the virus under control so the immune system can recover and the risk of passing HIV on is greatly reduced.

How It Works

Atazanavir is a protease inhibitor. HIV needs an enzyme called protease to cut its proteins into working pieces when it makes new virus particles. Atazanavir blocks this enzyme, so the new virus particles are faulty and cannot infect more cells. It is usually "boosted" with a small dose of Ritonavir or Cobicistat, which slows its breakdown and keeps blood levels high enough.

Dosage and Administration

Take exactly as prescribed by your HIV doctor. A common adult regimen is 300 mg once daily taken together with Ritonavir 100 mg once daily, with food. In some adults the doctor may use 400 mg once daily with food without a booster. Children's doses are based on body weight and are set by the doctor. Swallow the capsules whole with a meal. Take it at the same time every day and never miss doses or stop on your own, as this can make the virus resistant.

Interactions

• Proton pump inhibitors such as Omeprazole and Esomeprazole greatly reduce absorption; they are usually avoided or used only under strict advice.
• H2 blockers (such as Famotidine) and antacids: timing must be separated as advised; take Atazanavir about 2 hours before or 1 hour after antacids.
• Must not be combined with Rifampicin, St John's wort, Simvastatin, Lovastatin, oral Midazolam, Triazolam, ergot medicines, Alfuzosin, Irinotecan or Sildenafil used for lung hypertension.
• Can raise levels of many medicines, including some heart, cholesterol, erectile dysfunction and sedative medicines, and inhaled or injected corticosteroids such as Fluticasone.
• May reduce the effect of some hormonal contraceptives.

Always tell every doctor and pharmacist that you take Atazanavir.

Contraindications

• Allergy to Atazanavir or any ingredient.
• Moderate to severe liver impairment.
• Use with the interacting medicines listed above that must not be combined.

Side Effects

The most common effect is a rise in bilirubin, which can cause yellowing of the eyes or skin; this is often harmless but should be reported. Other effects include nausea, diarrhoea, headache, stomach pain, tiredness and rash. Less often it can cause kidney or gallbladder stones, changes in heart rhythm (slow heartbeat or PR prolongation), raised blood sugar and liver problems.

Get urgent medical help if you have a severe rash with blisters, peeling skin or mouth sores, severe pain in the side or back or blood in the urine, fainting or a very slow or irregular heartbeat, dark urine with pale stools and stomach pain, or swelling of the face or difficulty breathing.

Pregnancy and Lactation

Boosted Atazanavir can be used in pregnancy when the doctor decides it is suitable; treating HIV in pregnancy greatly reduces the risk of passing the virus to the baby. Do not stop treatment if you become pregnant; talk to your doctor quickly. Advice on breastfeeding with HIV differs by situation, so discuss feeding choices with your HIV doctor.

Precautions and Warnings

• People with hepatitis B or C have a higher risk of liver problems and need liver tests.
• Drink plenty of fluids to lower the risk of kidney stones.
• Use with care in people with heart conduction problems, diabetes, haemophilia or kidney disease.
• As the immune system recovers, old hidden infections may flare up (immune reconstitution); report new symptoms.
• Atazanavir does not stop HIV being passed on through sex or blood completely; use condoms and never share needles.

Overdose

An overdose may cause jaundice (yellow skin and eyes) and heart rhythm changes. Contact a doctor or go to the nearest hospital straight away if too much has been taken.

Therapeutic Class

Antiretroviral, HIV protease inhibitor.

Storage

Store below 30°C in a dry place, away from light and out of the reach of children.