Last Updated June 10, 2016
Deladex, Videx, Aspen Didanosine, Sonke Didanosine
Nucleoside reverse transcriptase inhibitor antiretroviral
25 mg, 50 mg, 100 mg, 150 mg tablets; 250 mg, 400 mg capsules; 250 mg, 400 mg enteric-coated (EC) capsules
Indication: treatment of HIV infection in combination with other antiretrovirals.
Mechanism of action*: an adenosine analogue that is phosphorylated intracellularly to dideoxyadenosine triphosphate, which interferes with HIV viral RNA-dependent DNA polymerase inhibiting viral replication.
Pharmacokinetics*: renal excretion 50%. Half-life: serum = 1.5 hours; intracellular = > 20 hours; subject to degradation by acidic pH of the stomach. Oral availability decreased with food. Cerebrospinal fluid penetration ~ 20% in adults.
Use in Renal or Hepatic Insufficiency: Reduce dose in renal or hepatic impairment.
Dosage for patients with chronic kidney disease or end-stage renal disease†:
Body weight ≥ 60 kg usual dose: 200 mg twice daily.
Body weight < 60 kg usual dosage: 125 mg twice daily orally.
Dosage for patients with chronic kidney disease or end-stage renal disease:
Body weight ≥ 60 kg usual dosage: 400 mg/day orally.
Body weight < 60 kg usual dosage: 250 mg once daily orally.
Use in Pregnancy and Breastfeeding: Category B. Excretion into breast milk is not known. Infants of mothers taking didanosine should not be breast-fed.
Use in Children: 180-240 mg/m2 daily in 1-2 divided doses. Maximum: 400 mg/day.
US Prescribing Information Boxed Warning*: fatal and nonfatal pancreatitis has occurred and should be discontinued in anyone with suspected pancreatitis.
US Prescribing Information Boxed Warning*: lactic acidosis/hepatomegaly with steatosis has been reported with nucleoside analogues with fatal cases reported. Use in caution with patients with risk factors for liver disease and suspend treatment if a patient develops signs and symptoms. Fatal lactic acidosis has been reported in pregnant women who received the combination of didanosine and stavudine.
Infants of mothers taking didanosine should not be breast-fed.
Contraindicated*: ribavirin, allopurinol.
See above for pregnancy and lactation.
Administration to children may be difficult because drug must be taken on an empty stomach.
Mothers taking didanosine should not breast-feed their infants.
Peripheral neuropathy, retinal changes (optic neuritis), nausea, vomiting, insulin resistance/diabetes mellitus, potential association with noncirrhotic portal hypertension.*
Pancreatitis (see Warnings).*
Lactic acidosis/hepatomegaly (see Warnings).*
*Information from US prescribing information.
†Recommendation from South African Renal Society, 2008.