There are many precautions and warnings with abacavir to be aware of before starting treatment with the medication. For example, you should let your healthcare provider know if you have liver disease, anemia, or any allergies prior to taking the drug. Precautions and warnings with abacavir also extend to pregnant and breastfeeding women, as well as people who are allergic to any of the ingredients used to make abacavir.

• Liver disease, such as liver failure or cirrhosis
• Heart disease
• High blood pressure (hypertension)
• High cholesterol
• Diabetes
• Anemia, neutropenia, or any other low blood count or blood disorder
• Any allergies, including allergies to food, dyes, or preservatives.
   

 

• Pregnant or thinking of becoming pregnant
• Breastfeeding
• A smoker.
   

• Abacavir often causes allergic reactions. These reactions can be extremely dangerous. You should stop taking abacavir and contact your healthcare provider immediately if you develop symptoms from two or more of the following groups of symptoms:

 

• Group 1 -- Fever
• Group 2 -- Rash
• Group 3 -- Nausea, vomiting, diarrhea, or abdominal pain (stomach pain)
• Group 4 -- Extreme fatigue, a general ill feeling (malaise), or achiness
• Group 5 -- Shortness of breath, coughing, or a sore throat. 

If you have ever had an allergic reaction to abacavir, you should never take abacavir (or any other medication containing abacavir) again. Recent research has discovered that people with a certain gene (known as the HLA-B*5701 allele) are at a high risk for an allergic reaction to abacavir. It is now recommended that everyone be tested for this gene before starting the medication. If you have the gene, you should not take abacavir. If you do not have the gene, an allergic reaction is still possible (but is much less likely).

• Rarely, abacavir causes lactic acidosis or hepatic steatosis. These conditions are caused by damage to the liver and can be very dangerous. You are at a higher risk for these conditions if you have liver disease.

  

• Abacavir can cause bone marrow depression, which means that the medication can decrease the bone marrow's ability to produce blood cells. This can lead to a variety of problems, such as anemia, frequent infections, or bleeding. Your healthcare provider should check your blood counts frequently while you are taking abacavir.

 

• Some studies have suggested that abacavir may increase the risk of heart attacks. You should take measures to reduce your risk factors for heart disease (such as high blood pressure, high cholesterol, diabetes, or smoking). If you have heart disease, this medication may not be the best choice for you.

 

• Abacavir can change the distribution of fat on your body. The medication may cause you to gain fat in areas that are not typical for you, such as in the abdomen or at the back of the neck (a "buffalo hump"), and it may cause you to lose weight in other areas.

 

• Abacavir is not a cure for HIV or AIDS. If you have HIV or AIDS, you should always use safer sex practices, regardless of whether you are taking medications.
   
• As with all HIV medications, it is important that you take abacavir exactly as prescribed. Missing doses may increase the chance of the virus becoming resistant to HIV medications.
   
• Abacavir can interact with a number of different medications (see Drug Interactions With Abacavir for more information).
   
• Abacavir is considered a pregnancy Category C medication. This means that it may not be safe for use during pregnancy, although the full risks are not known (see Ziagen and Pregnancy).
   
• It is not known if abacavir passes through breast milk. Therefore, if you are breastfeeding or plan to start breastfeeding, discuss this with your healthcare provider prior to taking the drug (see Ziagen and Breastfeeding). It is important to understand that the HIV virus can be transmitted through breast milk and that breastfeeding is usually not recommended in women with HIV or AIDS.