Indications
Abacavir is an antiretroviral medicine used, always in combination with other HIV medicines, to treat HIV-1 infection in adults, adolescents and children. It is often supplied in combination tablets with Lamivudine, and sometimes with Zidovudine or Dolutegravir. It does not cure HIV or AIDS, but it keeps the virus under control so the immune system can recover.
How It Works
Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI). Inside cells it is converted to an active form that blocks reverse transcriptase, the enzyme HIV uses to copy its genetic material. This lowers the amount of virus in the blood and helps raise the CD4 cell count.
Dosage and Administration
Take exactly as prescribed by your HIV doctor. For adults the usual total dose is 600 mg a day, taken either as 600 mg once daily or 300 mg twice daily, with or without food, together with other HIV medicines. Children’s doses depend on body weight. Before starting, a blood test for the HLA-B*5701 gene should be done, because people with this gene have a high risk of a serious allergic reaction. Take it every day without missing doses, and do not stop on your own.
Interactions
- Alcohol increases abacavir levels in the blood.
- Abacavir may slightly lower Methadone levels; the methadone dose may need checking.
- It may increase the effect of Riociguat.
- Phenytoin, Phenobarbital and Rifampicin may lower abacavir levels.
Tell your doctor about all medicines and herbal products you take.
Contraindications
Do not take abacavir if you are allergic to it, if you carry the HLA-B*5701 gene, if you have ever had a hypersensitivity reaction to any abacavir-containing medicine, or if you have moderate or severe liver disease.
Side Effects
- Nausea, vomiting, diarrhoea, loss of appetite
- Headache, tiredness, trouble sleeping, unusual dreams
- Rash
- Rarely, lactic acidosis (acid build-up in the blood) and enlarged fatty liver
- Changes in body fat and immune reconstitution reactions (old infections flaring as immunity recovers)
Abacavir can cause a serious, possibly life-threatening allergic reaction, usually in the first 6 weeks. Stop taking it and get urgent medical help if you have symptoms from 2 or more of these groups: fever; rash; nausea, vomiting, diarrhoea or stomach pain; severe tiredness, aches or generally feeling ill; shortness of breath, cough or sore throat. Never take abacavir again after such a reaction, as restarting can be fatal. Also get urgent help for chest pain or signs of a heart attack, severe weakness with fast breathing, or yellowing of the skin or eyes.
Pregnancy and Lactation
Abacavir can be used in pregnancy when your HIV doctor decides it is appropriate; do not stop treatment if you become pregnant, but speak to your doctor straight away. Breastfeeding advice for mothers living with HIV depends on local guidelines and viral load, so follow your doctor’s advice.
Precautions and Warnings
Carry the warning card supplied with the medicine. Tell your doctor about heart disease or risk factors (smoking, high blood pressure, diabetes, high cholesterol), liver disease, or hepatitis B or C. HIV treatment reduces but does not remove the risk of passing HIV to others. Keep regular appointments and blood tests.
Overdose
There is no specific antidote. Contact a doctor or go to hospital straight away if too much has been taken.
Therapeutic Class
Antiretroviral, nucleoside reverse transcriptase inhibitor (NRTI).
Storage
Store below 30°C in a dry place, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.