Abacavir

Abacavir should be avoided in moderate hepatic and renal impairment (unless essential), avoid in severe. HYPERSENSITIVITY REACTIONS: Life-threatening hypersensitivity reactions reported, characterised by fever or rash and possibly nausea, vomiting, diarrhoea, abdominal pain, lethargy, malaise, headache, myalgia, and renal failure; less frequently mouth ulceration, oedema, hypotension, dyspnoea,sore throat, cough paraesthesia, arthralgia, conjunctivitis, lymphadenopathy, lymphocytopenia and anaphylaxis (CSM has identified hypersensitivity reactions presenting as sore throat, influenza-like illness, cough and breathlessness); rarely myolysis; laboratory abnormalities may include raised liver function tests and creatine phosphokinase; symptoms usually appear in the first 6 weeks, but may occur at any time; monitor for symptoms every two weeks for two months; discontinue immediately if any symptom of hypersensitivity develops and do not rechallenge (risk of more severe hypersensitivity reaction); discontinue if hypersensitivity cannot be ruled out, even when other diagnoses possible, if rechallenge necessary it must be carried out in hospital setting; if abacavir is stopped for any reason other than hypersensitivity , exclude hypersensitivity reaction as the cause and rechallenge only if medical assistance is readily available; care needed with concomitant use of drugs which cause skin toxicity.COUNSELLING: Patients 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 ytreatment; patients should be advised to keep Allert card with them at all times. HEPATIC DISEASE:Potentially life-threatening lactic acidosis and severe hepatomegaly with steatosis reported therefore caution in liver disease , liver enzyme abnormalities, or risk factors for liver disease (perticularly in obese women); suspend or discontinue if deterioration in liver function tests, hepatic steatosis, prograssive hepatomegaly or unexplained lactic acidosis.