SYNABAC ( TABLET )

• Hepatic impairment
• Renal impairment
• Pregnancy
• Lactation
• Hypersensitivity reaction
• Interactions

• Life-threatening hypersensitivity reactions reported-characterized 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 (hypersensitivity reactions presenting as sore throat, influenza-like illness, cough and breathlessness identified)
• Rarely, myolysis
• Laboratory abnormalities may include raised liver enzymes and creatine kinase
• Symptoms usually appear in the first 6 weeks, but may occur at any time
• Monitor for symptoms every 2 weeks for 2 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 diagnosis 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. Patients should be told the importance of regular dosing (intermittent therapy may increase sensitization), how to recognize signs of hypersensitivity and advised to seek immediate medical attention if symptoms develop or before re-starting treatment. Potentially life-threatening lactic acidosis and severe hepatomegaly with steatosis reported-caution in liver disease, liver enzyme abnormalities, or risk factors for liver disease (particularly in obese women)
• Suspend or discontinue if deterioration in liver function tests, hepatic steatosis, progressive hepatomegaly or unexplained lactic acidosis.

Store at a temperature not exceeding 30°C.

• Pregnancy
• Lactation
• Hepatic dysfunction
• Renal disease
  Chronic hepatitis B or C, hepatic impairment; renal impairment; Exercise caution in patients (particulary obese women) with hepatomegaly, hepatitis, liver enzyme abnormalities, or risk factors for liver disease and hepatic steatosis (including alcohol abuse) and discontinur if rapid deterioration in liver function tests, symptomatic hyperlactataemia, progressive hepatomegaly, or lactic acidosis occurs. To reduce the risk hypersensitivity reactions, perform HLA-B*5701 testng before initiating an abacavir - containing treatment regimen. Do not prescribe/administer abacavir to an HLA-B*5701-positive patient, and clearly record the positie status as an abacavir allergy in the patient's medical record. If HLA-B*5701 screening is not readily available, initiation of abacavir is reasonable with appropriate clinical counseling and monitoring for any signs of hypersensitivity reaction.
  
   

HIV infection in combination with atleast two other antiretroviral drugs.

Source : IAP Pediatric Drug Formulary 
HIV infection in combination with at least two other antiretroviral medicines, by mouth, adolescent - 300 mg twice daily; 3 months-16 years, 8 mg/kg twice (maximum, 600 mg daily).

• For adolescents, the initiation of antiretroviral therapy is recommended in any patient: with a history of an AIDS-defining infection; with a CD4 < 350/mm3; who is pregnant; who has HIV-associated nephropathy; or who is being treated for hepatitis B (HBV) infection.
• For children. the initiation of antiretroviral therapy is recommended in any symptomatic patient.
• For asymptomatic or mildly symptomatic children >=5 years. The initiation of antiretroviral therapy is recommended for patients with HIV RNA >= 100,000 copies/ml and CD4 < 350/mm3.
• For asymptomatic or mildly symptomatic children 1-5 years. The initiation of antiretroviral therapy is recommended for patients with HIV RNA >= 100,000 copies/ ml and CD4 < 25%.
• For infants, the initiation of antiretroviral therapy is recommended in any infant regardless of clinical status, CD4 percentage, or viral load.

Source : National Formulary of India

• Oral Adult- 300 mg twice daily or 600 mg once daily.
• Child- 3 months to 12 years: 8 mg/kg body weight every 12 h (max. 600 mg daily).

Contraindications

Contraindications

Abacavir administered orally is rapidly and extensively absorbed. Once in the systemic circulation, abacavir distributes into extravascular space. Protein binding is approximately 50% and is independent of concentration. Based on radiolabeled studies, the drug readily distributes into erythrocytes. In humans, abacavir is not significantly metabolized by cytochrome P450 enzymes. The primary routes of elimination of abacavir are metabolism by alcohol dehydrogenase (to form the 5'-carboxylic acid) and glucuronyl transferase (to form the 5' glucuronide). The metabolites have no antiviral activity. Elimination is mainly via kidney, mostly in conjugated form. Fecal elimination accounts for 15% of the dose. Elimination half-life 1.54 ± 0.63 hours.

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