Ziagen (Abacavir)
Ziagen (Abacavir) Dosage and Side Effects
The Human Immunodeficiency Virus (HIV) is a retrovirus (a type of virus). Infection with HIV damages the immune system and can lead to Acquired Immune Deficiency Syndrome (AIDS) and other related illnesses. ZIAGEN belongs to a group of antiretroviral medicines called nucleoside analogue reverse transcriptase inhibitors (NRTIs), and is used in combination with other antiretrovirals to treat HIV infection.
Warnings and Precautions
Hypersensitivity Reaction:
You should be screened for the HLA-B*5701 gene variation prior to starting or re-starting treatment with ZIAGEN. Patients who have the HLA-B*5701 gene variation have a high risk of developing a hypersensitivity reaction (serious allergic reaction) to abacavir, which is in the drug ZIAGEN. This hypersensitivity reaction can be life threatening if you continue to take ZIAGEN.
Build-up of acid in your blood (lactic acidosis) and swollen and fatty liver:
Lactic acidosis (too much acid in the blood) and swollen and fatty liver (hepatomegaly with steatosis), including fatal cases, have been reported in patients using nucleoside analogues alone or in combination. If you suffer symptoms, contact your doctor.
If you stop ZIAGEN because of a serious allergic reaction, never take ZIAGEN or any other medicine containing abacavir (such as KIVEXA, TRIZIVIR or TRIUMEQ) again, regardless of whether you have the HLA-B*5701 gene variation or not. Within hours you may experience a life-threatening lowering of your blood pressure or death. If you stop ZIAGEN for any other reason, even for a few days, and you are not allergic to ZIAGEN, talk with your doctor before taking it again. Taking ZIAGEN again may cause a serious allergic or life-threatening reaction, even if you never had an allergic reaction to it before.A list of these symptoms is on the Warning Card provided by your pharmacist. You should carry this Warning Card with you at all times. If you notice these symptoms while taking ZIAGEN, call your doctor immediately. Your doctor may advise you to stop taking ZIAGEN.
If your healthcare provider tells you that you can take ZIAGEN, again, start taking it when you are around medical help or people who can call a doctor if you need one.
Occasionally, reactions have developed in people who start taking abacavir again, and had only one symptom on the Warning Card before they stopped taking it.
If you are hypersensitive to ZIAGEN, return all your unused ZIAGEN tablets for safe disposal. Ask your doctor or pharmacist for advice.
Before you use ZIAGEN, talk to your doctor or pharmacist:
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About all your medicines and medical conditions
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If you have liver disease
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If you have been tested and know whether or not you have a gene variation called HLA-B*5701
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If you are pregnant, or planning to become pregnant, breastfeeding or planning to breastfeed
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About all the medicines you are taking including vitamins, herbal supplements and nonprescription drugs
Other Special Warnings:
The class of medicines to which ZIAGEN belongs (NRTIs) can cause a condition called lactic acidosis (excess of lactic acid in your blood), together with an enlarged liver. Symptoms of lactic acidosis include feeling of weakness, loss of appetite, sudden unexplained weight loss, upset stomach and difficulty breathing or rapid breathing. This rare, but serious side effect occurs more often in women. If you have liver disease you may also be more at risk of getting this condition. While you are being treated with ZIAGEN your doctor will monitor you closely for any signs that you may be developing lactic acidosis.
Some HIV medicines including abacavir may increase your risk of heart attack. If you have heart problems, smoke or suffer from diseases that increase your risk of heart disease such as high blood pressure and diabetes, tell your doctor. Do not stop taking your medication unless you are advised to do so by your doctor.
You may continue to develop other infections and other illnesses associated with HIV disease. You should therefore keep in regular contact with your doctor while taking ZIAGEN.
Treatment with ZIAGEN has not been shown to reduce the risk of passing HIV infection on to others by sexual contact or by blood transfer. You should continue to use appropriate precautions to prevent this.
ZIAGEN oral solution contains sorbitol which may cause stomach (abdominal) pain and diarrhea. Sorbitol changes to fructose in the body and not recommended for patients who cannot tolerate fructose.
Use of this medicine during pregnancy and breastfeeding:
If you are pregnant, or planning to become pregnant soon, you must inform your doctor before taking any medicine. The safe use of ZIAGEN in pregnancy has not been established. Your doctor will decide whether you should continue to be treated with ZIAGEN if you are pregnant. If you take ZIAGEN while you are pregnant, talk to your doctor about how you can be included in the Antiretroviral Pregnancy Registry.
Babies and infants exposed to Nucleoside Reverse Transcriptase Inhibitors (NRTIs) during pregnancy or labour show minor temporary increases in blood levels of lactate. The clinical importance of these temporary increases is unknown.
These findings do not affect current recommendations to use antiretroviral therapy in pregnant women to prevent transmission of HIV to their babies. There have been very rare reports of disease that affect the neonatal (babies) nervous system such as delayed development and seizures. The long term effects of ZIAGEN are not known.
It is recommended that HIV infected women do not breastfeed their infants under any circumstances in order to avoid transmission of HIV from mother to child. The active substance in ZIAGEN (abacavir) is likely to be found in breast milk.
You are recommended not to breastfeed your baby while taking ZIAGEN.
REMEMBER: This medicine is for you. Never give it to someone else. It may harm them even if their symptoms are the same as yours.
Side Effects
Like all medicines, ZIAGEN can have side effects. When treating HIV infection, it is not always possible to tell whether some of the undesirable effects that occur are caused by ZIAGEN, by other medicines you are taking at the same time or by the HIV infection. For this reason it is very important that you inform your doctor about any changes in your health.
A hypersensitivity reaction (serious allergic reaction) has been reported in patients who have been treated with ZIAGEN. This is described in the section on Hypersensitivity Reaction in the beginning of this leaflet. It is important that you read and understand the information about this serious reaction.
The most common side effects (could affect at least 1 in 10 in every 100 people) are nausea (feeling of sickness), vomiting, lethargy (unusual lack of energy), fatigue, anorexia (loss of appetite), fever (high temperature), headache, diarrhea, hyperlactatemia (high blood lactate level) and skin rash (without any other illness). If these symptoms persist or become bothersome, contact your doctor.
Other side effects include: Rare (could affect <1 in 1000 people): lactic acidosis (excess of lactic acid in your blood) and inflammation of the pancreas (pancreatitis). This may result in increasing pain and discomfort in the upper abdomen and may be accompanied by nausea and vomiting. However, it is not known whether this is caused by ZIAGEN, other medicines you may be taking or your HIV infection.
Very rare (could affect less <1 in 10 000 people): serious skin reactions which include erythema multiforme (a skin condition characterized by a red rash), Stevens-Johnson syndrome (a severe and sometimes fatal skin rash) and toxic epidermal necrolysis (a life-threatening skin disorder characterized by blistering and peeling of the skin).
Changes in body fat have been seen in patients taking antiretroviral therapy. These changes may include increased amount of fat on the upper back and neck (“buffalo hump”), breasts, and around the trunk. Loss of fat from the legs, arms, and face may also happen. The cause and long-term health effect of these conditions is not known at this time.
Changes in your immune system (Immune Reconstitution Syndrome) can happen when you start taking HIV medicines. Your immune system may get stronger and begin to fight infections that have been hidden in your body for a long time, or you could develop an autoimmune disease in which your immune system reacts against your own body (e.g. Graves' disease (which affects the thyroid gland), Guillain-Barré syndrome (which affects the nervous system) or polymyositis (which affects the muscles) and it may develop at any time, sometimes months later after the start of HIV therapy). Sometimes symptoms can be severe, so if you develop high temperature (fever), joint or muscle pain, redness, rash, swelling, or fatigue or any new symptoms contact your doctor straight away.
Interactions with this medication
ZIAGEN is unlikely to interact with other medicines you are being treated with; however, it is important that you tell your doctor or pharmacist about all the medicines listed below or any that you are taking or have recently taken, including those you have bought yourself:
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Methadone
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Retinoids
If you are taking methadone, your doctor may need to adjust your methadone dose, as abacavir increases the rate at which methadone leaves your body. This is unlikely to affect most methadone users.
In men, alcohol does increase the amount of abacavir in your blood. However, the meaning of this is unknown. This interaction has not been studied in women.
Proper Use of this medication
Usual dose:
Take ZIAGEN tablets exactly as your doctor has advised you, and try not to miss any doses. If you are unsure about how to take it, ask your doctor or pharmacist.
An oral solution (20 mg abacavir/mL) is available for the treatment of children and adult patients unable to swallow tablets.
Adults weighing at least 25 kg:
The recommended oral dose of ZIAGEN for adults is 600 mg daily administered as either 300 mg twice daily or 600 mg once daily, in combination with other antiretroviral agents.
Adolescents and children weighing at least 25 kg:
The recommended dose of ZIAGEN is 300 mg (one tablet or 15 mL of oral solution) twice daily or 600 mg once daily (two tablets or 30 mL of oral solution) in combination with other antiretroviral agents.
Adolescents and children (over three months of age) weighing less than 25 kg:
Tablets:
For children able to swallow tablets as determined by the doctor/parent:
Children weighing 14 to less than 20 kg: one-half of a scored abacavir tablet twice daily or one tablet taken once daily.
Children weighing more than 20 kg and less than 25 kg: one-half of a scored abacavir tablet taken in the morning and one whole tablet taken in the evening or one and a half tablets taken once daily.
Oral Solution:
The recommended oral dose of ZIAGEN for adolescents and children over 3 months of age is 8 mg/kg twice daily (up to a maximum of 300 mg twice daily) or 16 mg/kg once daily (up to a maximum of 600 mg once daily) in combination with other antiretroviral agents.
Children less than three months of age:
There are insufficient data to recommend the use of ZIAGEN in infants less than three months old.
The daily dose of ZIAGEN may need to be reduced in some patients with liver disease.
ZIAGEN can be taken with food or on an empty stomach.
Overdose:
If you are concerned that you may have taken too much ZIAGEN, contact a health care practitioner, hospital emergency department or regional Poison Control Centre immediately, even if there are no symptoms.
Missed dose:
It is important to take this medicine as prescribed to ensure you get maximum benefit. If you forget to take a dose, take it as soon as you remember, and then continue as before. Do not take a double dose to make up for forgotten individual doses.
If you stopped taking ZIAGEN:
If you stop taking ZIAGEN because of side effects or illness, you must contact your doctor before restarting to make sure that symptoms of a hypersensitivity reaction have not been missed. In some cases your doctor will ask you to restart ZIAGEN under direct medical supervision or in a place where you will be able to get ready access to medical care if needed.
Other related products
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.
