Trade Names:Videx- Powder for oral solution, pediatric 2 g- Powder for oral solution, pediatric 4 g
Trade Names:Videx EC- Capsules, delayed-release (with enteric-coated beadlets) 125 mg- Capsules, delayed-release (with enteric-coated beadlets) 200 mg- Capsules, delayed-release (with enteric-coated beadlets) 250 mg- Capsules, delayed-release (with enteric-coated beadlets) 400 mg
Inhibits replication of HIV by interfering with DNA synthesis.
T max is 0.25 to 1.5 h (buffered formulation), 2 h (delayed-release). Bioavailability is approximately 42% (buffered formulation). Food decreases the C max and AUC by approximately 55% when didanosine tablets were administered up to 2 h after a meal. C max and AUC of the delayed-release capsules decreased by approximately 46% and 19%, respectively, in the presence of food. Should be taken on an empty stomach.
Less than 5% protein bound. Vd is approximately 43.7 L/m 2 .
Half-life is approximately 1.5 h (buffered formulation). Approximately 18% recovered in the urine (buffered formulation). Renal Cl is approximately 458 mL/min (buffered formulation) in patients with CrCl of at least 90 mL/min.
Half-life is increased and Cl is decreased. Dosage reduction recommended in those with CrCl less than 60 mL/min.Hepatic Function Impairment
Mean C max and AUC were 19% and 13% higher, respectively. No dosage adjustment required.
Treatment of HIV-1 infection in combination with other antiretrovirals.
POPatients weighing 60 kg or more
200 mg twice daily. For patients who require once-daily dosing, administer 400 mg once daily.Patients weighing less than 60 kg
125 mg twice daily. For patients who require once-daily dosing, administer 250 mg once daily.Children
PO2 wk to 8 mo of age
100 mg/m 2 twice daily.Older than 8 mo of age
120 mg/m 2 twice daily.Videx ECAdults and Children
POPatients weighing 20 kg to less than 25 kg
200 mg once daily.Patients weighing 25 kg to less than 60 kg
250 mg once daily.Patients weighing 60 kg or more
400 mg once daily.Renal Function ImpairmentAdults
POVidex CrCl 60 mL/min or more
For patients weighing at least 60 kg, administer 200 mg twice daily; for patients weighing less than 60 kg, administer 125 mg twice daily.CrCl 30 to 59 mL/min
For patients weighing at least 60 kg, administer 200 mg once daily or 100 twice daily; for patients weighing less than 60 kg, administer 150 mg once daily or 75 mg twice daily.CrCl 10 to 29 mL/min
For patients weighing at least 60 kg, administer 150 mg once daily; for patients weighing less than 60 kg, administer 100 mg once daily.CrCl less than 10 mL/min and patients requiring continuous ambulatory peritoneal dialysis or hemodialysis
For patients weighing at least 60 kg, administer 100 mg once daily; for patients weighing less than 60 mg, administer 75 mg once daily.Videx EC CrCl 60 mL/min or more
For patients weighing at least 60 kg, administer 400 mg once daily; for patients weighing less than 60 kg, administer 250 mg once daily.CrCl 30 to 59 mL/min
For patients weighing at least 60 kg, administer 200 mg once daily; for patients weighing less than 60 kg, administer 125 mg once daily.CrCl 10 to 29 mL/min
Administer 125 mg.CrCl less than 10 mL/min and patients requiring continuous ambulatory peritoneal dialysis or hemodialysis
For patients weighing at least 60 kg, administer 125 mg once daily; do not administer to patients weighing less than 60 kg.Concomitant Tenofovir Disoproxil FumarateAdults
POVidex EC CrCl 60 mL/min or more and weighing at least 60 kg
Administer 250 mg once daily.CrCl 60 mL/min or more and weighing less than 60 kg
Administer 200 mg once daily.
Store powder at 59° to 86°F. Once mixed, store for up to 30 days in refrigerator at 36° to 46°F. Discard unused portion after 30 days.Videx EC
Store at 59° to 86°F.
Because allopurinol may cause increased didanosine plasma levels, do not coadminister.Antacids
Aluminum- or magnesium-containing antacids may potentiate adverse reactions associated with the antacid component of didanosine pediatric powder.Antiretroviral agents
Antiretroviral agents have caused fatal lactic acidosis in women when coadministered with didanosine.Delavirdine, indinavir
Administer 1 h prior to didanosine to avoid decreasing plasma levels of delavirdine or indinavir.Drugs that cause peripheral neuropathy or pancreatitis
Increased risk of these toxicities.Food
Reduces absorption of didanosine by as much as 50%.Fluoroquinolones, tetracyclines
Do not administer within 2 h of didanosine.Ganciclovir, valganciclovir
Didanosine plasma concentrations may be elevated, increasing the risk of toxicity.Itraconazole, ketoconazole, dapsone, and other drugs whose absorption can be affected by gastric acidity
Administer at least 2 h before didanosine.Methadone
May decrease didanosine plasma levels.Ribavirin
Risk of didanosine toxicity may be increased. Avoid coadministration.Tenofovir disoproxil fumarate
Didanosine plasma concentrations may be increased, necessitating a dose reduction in didanosine.
None well documented.
Incidences of the following adverse reactions were reported with didanosine monotherapy. When didanosine is used in combination with other agents with similar adverse reactions, the incidence of these reactions, including pancreatitis and hepatotoxicity, may be higher than with didanosine alone.
Peripheral neurologic symptoms/neuropathy (20%); asthenia (postmarketing).
Rash/pruritus (9%); alopecia (postmarketing).
Dry eyes, optic neuritis, retinal depigmentation (postmarketing).
Diarrhea (28%); pancreatitis (7%); anorexia, dry mouth, dyspepsia, flatulence, inflammation of the salivary gland (postmarketing).
Acute renal failure (postmarketing).
Hepatitis, liver failure, symptomatic hyperlactatemia/lactic acidosis and hepatic steatosis (postmarketing).
Anemia, leukopenia, thrombocytopenia (postmarketing).
Anaphylactic reactions (postmarketing).
Elevated serum amylase (17%); elevated ALT and AST (9%); elevated serum alkaline phosphatase (4%); elevated serum uric acid (3%); elevated serum gamma-glutamyltransferase, hyperglycemia, hypoglycemia (postmarketing).
Diabetes mellitus, redistribution/accumulation of body fat (postmarketing).
Arthralgia, myalgia, myopathy, rhabdomyolysis (postmarketing).
Abdominal pain (13%); chills/fever, pain, parotid gland enlargement (postmarketing).
Fatal and nonfatal pancreatitis have occurred during therapy regardless of the degree of immunosuppression. Withhold treatment in patients with suspected pancreatitis and discontinue in patients with confirmed pancreatitis.Lactic acidosis and severe hepatomegaly
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported. Fatal lactic acidosis has been reported in pregnant women receiving the combination of didanosine and stavudine with other antiretroviral agents.
Monitor for diarrhea in patients receiving oral solution. Monitor uric acid levels closely for possible asymptomatic hyperuricemia.
Category B .
Undetermined. HIV-infected mothers should not breast-feed infants.
Safety and efficacy not established in children younger than 2 wk of age.
Select dose with caution because of greater likelihood of decreased renal function.
Dosage reduction is recommended with CrCl less than 60 mL/min. Adjust dose in renal impairment.
Hepatic failure has occurred in children. Dose adjustment is not needed. Hepatotoxicity and hepatic failure resulting in death have been reported during postmarketing experience in patients receiving hydroxyurea and other antiretroviral agents.
May be genotoxic.
Redistribution/accumulation of body fat (eg, central obesity, dorsocervical fat enlargement [buffalo hump]) has been observed in patients receiving antiretroviral therapy.
Fatal cases of severe hepatomegaly with steatosis have been reported.
Asymptomatic hyperuricemia may occur.
Has been reported in patients receiving combination antiretroviral therapy, including didanosine. During the initial phase of treatment, patients may develop an inflammatory response to indolent or residual opportunistic infections (eg, Mycobacterium avium ), necessitating further evaluation and treatment.
Occurs frequently; may be dose-related.
Retinal changes and optic neuritis have been reported in adults and children.
Each single-dose powder packet contains sodium 1,380 mg.
Diarrhea, hepatic dysfunction, hyperuricemia, pancreatitis, peripheral neuropathy.
Copyright © 2009 Wolters Kluwer Health.