Didanosine indications and usage

# Indications and Usage
VIDEX (didanosine, USP), also known as ddI, in combination with other antiretroviral agents is indicated for the treatment of human immunodeficiency virus (HIV)-1 infection.

## Dosage and Administration
VIDEX should be administered on an empty stomach, at least 30 minutes before or 2 hours after eating.

## Recommended Dosage (Adult and Pediatric Patients)
The preferred dosing frequency of VIDEX is twice daily because there is more evidence to support the effectiveness of this dosing regimen. Once-daily dosing should be considered only for patients whose management requires once-daily dosing of VIDEX . The recommended adult total daily dose is based on body weight (kg) (see Table 1).
- Adult Patients
- Pediatric Patients (2 weeks old to 18 years old):
The recommended dose of VIDEX (didanosine) in pediatric patients between 2 weeks old and 8 months old is 100 mg/m2 twice daily, and the recommended VIDEX dose for pediatric patients greater than 8 months old is 120 mg/m2 twice daily but not to exceed the adult dosing recommendation.
Dosing recommendations in patients less than 2 weeks of age cannot be made because the pharmacokinetics of didanosine in these children are too variable to determine an appropriate dose. There are no data on once-daily dosing of VIDEX in pediatric patients.

## Renal Impairment
- Adult Patients
In adult patients with impaired renal function, the dose of VIDEX should be adjusted to compensate for the slower rate of elimination. The recommended doses and dosing intervals of VIDEX in adult patients with renal insufficiency are presented inTable 2.
- Pediatric Patients
Urinary excretion is also a major route of elimination of didanosine in pediatric patients, therefore the clearance of didanosine may be altered in pediatric patients with renal impairment. Although there are insufficient data to recommend a specific dose adjustment of VIDEX in this patient population, a reduction in the dose should be considered (see Table 2).
- Patients Requiring Continuous Ambulatory Peritoneal Dialysis (CAPD) or Hemodialysis
For patients requiring CAPD or hemodialysis, follow dosing recommendations for patients with creatinine clearance of less than 10 mL/min, shown in Table 2. It is not necessary to administer a supplemental dose of VIDEX following hemodialysis.

## Dosage Adjustment
- Concomitant Therapy with Tenofovir,Disoproxil and Fumarate
In patients who are also taking tenofovir disoproxil fumarate, a dose reduction of VIDEX to 250 mg (adults weighing at least 60 kg with creatinine clearance of at least 60 mL/min) or 200 mg (adults weighing less than 60 kg with creatinine clearance of at least 60 mL/min) once daily is recommended. VIDEX and tenofovir disoproxil fumarate may be taken together in the fasted state. Alternatively, if tenofovir disoproxil fumarate is taken with food, VIDEX should be taken on an empty stomach (at least 30 minutes before food or 2 hours after food). The appropriate dose of VIDEX coadministered with tenofovir disoproxil fumarate in patients with creatinine clearance of less than 60 mL/min has not been established. (; see the complete prescribing information for VIDEX EC (enteric-coated formulation of didanosine) for results of drug interaction studies of tenofovir disoproxil fumarate with reduced doses of the enteric-coated formulation of didanosine.)
- Hepatic Impairment
No dose adjustment is required in patients with hepatic impairment.