ABACAVIR (ZIAGEN)

PATIENT INFORMATION

 What is Abacavir?

Abacavir, sold under the brand name Ziagen), is an antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body. Abacavir is used to treat HIV, the virus that can cause acquired immunodeficiency syndrome (AIDS).

Abacavir is for adults and children who are at least 3 months old. Abacavir is not a cure for HIV or AIDS.

Warnings about Abacavir

You should not take Abacavir if you have ever had an allergic reaction to any medicine that contains Abacavir, if you have moderate to severe liver disease, or if you have a gene variation called HLA-B*5701 allele.

You must stop using Abacavir and call your doctor at once if you have signs of an allergic reaction. These include: fever; rash; nausea, vomiting, diarrhea, stomach pain; general ill feeling, extreme tiredness, body aches; shortness of breath, cough, sore throat.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. You must call your doctor or get emergency medical help if you have unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or feeling very weak or tired.

Abacavir can also cause severe or life-threatening effects on your liver. You should call your doctor at once if you have pain or swelling in your upper stomach, tiredness, loss of appetite, dark urine, clay-coloured stools, or become jaundiced (yellowing of your skin or eyes).

Before taking Abacavir

You should not use Abacavir if:

• you have moderate or severe liver disease;
• you have a gene variation called HLA-B*5701 allele (your doctor will test you for this); or
• you have had an allergic reaction to any medicine that contains Abacavir (such as Ziagen, Epzicom, Triumeg, or Trizivir).

Many combination HIV medicines have Abacavir as an ingredient. Ziagen should not be taken together with any other medicine that contains Abacavir.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, if you have taken HIV medication for a long time, or if you are a woman. You must ask your doctor about your risk.

Tell your doctor if you have ever had:

• heart disease, high blood pressure (hypertension);
• a risk factor for heart disease such as smoking, diabetes mellitus, or high cholesterol (hypercholesterolaemia); 
• liver disease; or 
• if you have used any other HIV medication in the past.

You must tell your doctor if you are pregnant, and use your medications properly to control your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track any effects of antiviral medicine on the baby.

Women with HIV or AIDS should not breastfeed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

How should I take Abacavir?

You must follow all directions on your prescription label and read all medication guides or instruction sheets. You should use the medicine exactly as directed.

Abacavir comes with a Medication Guide and a Warning Card listing symptoms of an allergic reaction. You must read this information and learn what symptoms to watch for. You must keep the Wallet Card with you at all times.

Abacavir doses are based on weight in children and/ or teenagers. Your child's dose needs may change if the child gains or loses weight.

Abacavir can be taken with or without food.

Measure liquid medicine carefully. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

You will need frequent medical tests.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

Store at room temperature away from moisture and heat.

You may store the oral solution (liquid) in the refrigerator but do not let it freeze.

What happens if I miss a dose of Abacavir?

You must take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. You should not take two doses at one time.

You must get your prescription refilled before you run out of medicine completely. If you miss several doses, you may have a dangerous or even fatal allergic reaction once you start taking Abacavir again.

What happens if I overdose with Abacavir?

You should seek emergency medical attention or call the Poison Help line at 1-800-222-1222 (USA) or 111 in the UK (999 if it is an emergency).

What should I avoid while taking Abacavir?

You must avoid drinking alcohol. It may increase your risk of liver damage.

Taking Abacavir will not prevent you from passing HIV to other people. You must not have unprotected sex or share razors or toothbrushes. You should talk with your doctor about safe ways to prevent HIV transmission during sex. Sharing drug or medicine needles is never safe, even for a healthy person.

Abacavir side effects

You must stop using Abacavir and call your doctor at once if you have symptoms of an allergic reaction from two or more of these specific side effect groups:

• Group 1 - fever;
• Group 2 - rash;
• Group 3 - nausea, vomiting, diarrhoea, stomach pain;
• Group 4 - general ill feeling, extreme tiredness, body aches;
• Group 5 - shortness of breath, cough, sore throat.

Once you have had an allergic reaction to Abacavir, you must never use it again. If you stop taking Abacavir for any reason, you must talk to your doctor before you start taking the medication again.

Abacavir can cause other serious side effects that may not be signs of an allergic reaction. You should call your doctor at once if you have:

• severe upper stomach pain, nausea, vomiting, loss of appetite;
• swelling around your midsection;
• dark urine, clay-coloured stools, or become jaundiced (yellowing of the skin or eyes);
• unusual tiredness; or
• chest pain or pressure, pain spreading to your jaw or shoulder.

Mild symptoms of lactic acidosis may worsen over time, and this condition can be fatal. You should get emergency medical help if you have: unusual muscle pain, trouble breathing, stomach pain, vomiting, irregular heart rate, dizziness, feeling cold, or feeling very weak or tired.

Abacavir affects your immune system, which may cause certain side effects (even weeks or months after you have taken this medicine). You should tell your doctor if you have:

• signs of a new infection--fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhoea, weight loss;
• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or
• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Common side effects may include:

• feeling tired;
• sleep problems, strange dreams;
• headache, tiredness, fever, chills, general ill feeling;
• nausea or vomiting;
• rash; or
• (in children) stuffy nose, sneezing, sore throat, ear pain.

This is not a complete list of side effects and others may occur. You must call your doctor for medical advice about side effects. In USA, you may report side effects to FDA at 1-800-FDA-1088. In UK, you may report side effects online via the Yellow Card Scheme.

Abacavir dosing information

Usual Adult Dose for HIV Infection:

300 mg orally twice a day or 600 mg orally once a day.

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

Usual adult dose for non-occupational exposure:

US CDC recommendations: 300 mg orally twice a day or 600 mg orally once a day

Duration of therapy: 28 days

Comments:

-Recommended as part of alternative regimens (NNRTI-based, protease inhibitor-based, or triple NRTI) for non-occupational postexposure prophylaxis of  HIV infection.

-Prophylaxis should be started as soon as possible, within 72 hours of exposure.

-Current guidelines should be consulted for additional information.

Usual adult dose for occupational exposure:

US Public Health Service working group recommendations: 300 mg orally twice a day or 600 mg orally once a day.

Duration of therapy: 28 days, if tolerated.

Comments:

-Only with expert consultation, as part of an alternative regimen for use as HIV postexposure prophylaxis.

-Prophylaxis should be started as soon as possible, preferably within hours after exposure.

-The optimal duration of prophylaxis is unknown and may differ based on institution protocol.

-Current guidelines should be consulted for additional information.

Usual paediatric dose for HIV infection:

3 months or older:

Oral solution: 8 mg/kg orally twice a day or 16 mg/kg orally once a day.

Maximum dose: 600 mg/day.

Tablets:

14 to less than 20 kg: 150 mg orally twice a day or 300 mg orally once a day.

20 to less than 25 kg: 150 mg orally in the morning and 300 mg in the evening, or 450 mg orally once a day.

25 kg or more: 300 mg orally twice a day or 600 mg orally once a day.

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection

What other drugs will affect Abacavir?

You must tell your doctor about all your other medicines, especially:

• riociguat;
• methadone;or
• any other HIV medicines.

This list is not complete. Other drugs that may affect Abacavir, including prescription and over-the-counter medicines, vitamins, and herbal products.Not all possible drug interactions are listed here.

 

HEALTHCARE INFORMATION

 

Indication

HIV infection in combination with other antiretroviral drugs.

Dose

By mouth - For Adult

600 mg daily in 1–2 divided doses. 

Cautions

HIV load greater than 100 000 copies/mL; patients at high risk of cardiovascular disease. 

Side-effects

For all NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NRTIs):

Common or very common

Abdominal pain; anaemia (may require transfusion); asthenia; fever; dizziness; diarrhoea; headache; flatulence; insomnia; nausea; neutropenia; skin reactions; vomiting. 

Uncommon

Angioedema; pancreatitis.

Rare or very rare

Lactic acidosis.

Frequency unknown

Immune reconstitution inflammatory syndrome (IRIS); osteonecrosis; weight increased.

Side-effects, further information

Osteonecrosis has been reported in patients with advanced HIV disease or following long-term exposure to combination antiretroviral therapy.

Specific side effects for ABACAVIR

Common or very common

Appetite decreased; lethargy.

Rare or very rare

Severe cutaneous adverse reactions (SCARs).

Frequency unknown

Hypersensitivity.

Side-effects, further information

Life-threatening hypersensitivity reactions have been reported (characterised by fever or rash and possibly nausea, vomiting, diarrhoea, abdominal pain, dyspnoea, cough, lethargy, malaise, headache, and myalgia).

Less frequently mouth ulceration, oedema, hypotension, sore throat, acute respiratory distress syndrome (ARDS), anaphylaxis, paraesthesia, arthralgia, conjunctivitis, lymphadenopathy, lymphocytopenia and renal failure; rarely myolysis.

Laboratory abnormalities may include raised liver function tests (LFTs) and creatine kinase (CK); symptoms usually appear in the first 6 weeks, but may occur at any time.

Discontinue immediately if any symptom of hypersensitivity develops and do not rechallenge (risk of more severe hypersensitivity reaction).

Allergy and cross-sensitivity

Cross sensitivity

Caution

Increased risk of hypersensitivity reaction in presence of HLA-B*5701 allele.

Pregnancy

For all NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NRTIs):

Monitoring

Mitochondrial dysfunction has been reported in infants exposed to nucleoside reverse transcriptase inhibitors (NRTIs) in utero; the main effects include haematological, metabolic, and neurological disorders.

All infants whose mothers received nucleoside reverse transcriptase inhibitors (NRTIs) during pregnancy should be monitored for relevant signs or symptoms.

Hepatic impairment

For all NUCLEOSIDE REVERSE TRANSCRIPTASE INHIBITORS (NRTIs):

In general, manufacturers advise caution in patients with chronic hepatitis B or C (increased risk of hepatic side-effects).

Specific cautions for ABACAVIR:

Manufacturer advises caution in mild impairment; consider avoiding in moderate to severe impairment.

Renal impairment

Manufacturer advises avoid in end-stage renal disease.

Pre-treatment screening

Test for HLA-B*5701 allele before treatment or if restarting treatment and HLA-B*5701 status not known.

Monitoring requirements

Monitoring of patient parameters

Monitor for symptoms of hypersensitivity reaction every 2 weeks for 2 months.

Prescribing and dispensing information

Flavours of oral liquid formulations may include banana, or strawberry.

Patient and carer advice

Patients and their carers should be told the importance of regular dosing (intermittent therapy may increase the risk of sensitisation), how to recognise signs of hypersensitivity, and advised to seek immediate medical attention if symptoms develop or before re-starting treatment.

Patient resources

Patients should be provided with an alert card and advised to keep it with them at all times.

Medicinal forms

There can be variation in the licensing of different medicines containing the same drug.