Didanosine

DDI

Mechanism :

Didanosine is a synthetic purine nucleoside analogue active against the Human Immunodeficiency Virus. Intracellularly, didanosine is converted by cellular enzymes to the active metabolite, dideoxyadenosine 5-triphosphate. Dideoxyadenosine 5-triphosphate inhibits the activity of HIV-1 reverse transcriptase both by competing with the natural substrate, deoxyadenosine 5'-triphosphate, and by its incorporation into viral DNA causing termination of viral DNA chain elongation.

Indication :

• HIV Infection

Contraindications :

Didanosine is contraindicated in patients with previously demonstrated clinically significant hypersensitivity to any of the components of the formulations or if there is a previous history of pancreatic disease. Discontinue therapy if pancreatitis is suspected or pancreatic enzymes are raised. The drug formulations contain phenylalanine and should be avoided in phenylketonurics. Retinal or optic nerve changes have been reported in children and regular eye examinations are recommended at least 6 monthly or if vision disturbance occurs.

Therapy should be discontinued in cases of: peripheral neuropathy, hyperuricemia, raised liver enzymes, rapidly elevating aminotransferase levels, progressive hepatomegaly, hepatitis or lactic acidosis of unknown origin.

Dosing :

Adverse Effect :

Pancreatitis, peripheral neuropathy, abnormal liver function tests, lactic acidosis, hepatomegaly with steatosis, retinal changes, optic neuritis, hyperuricemia, nausea, vomiting, abdominal pain, diarrhea, constipation, taste disturbance, rash, pruritus, allergic reactions, anaphylaxis, leukopenia, thrombocytopenia and anemia.

Interaction :

Ciprofloxacin, Itraconazole, Ketoconazole and Dapsone: may reduce absorption. Avoid taking such drugs within 2 hours of didanosine.

Stavudine: Use with caution with other drugs that may be associated with pancreatic toxicity or peripheral neuropathy such as stavudine.

Renal Dose :

Hepatic Dose :