didanosine

Detailed Prescribing Information

October 2005

Forms Available

Dosing

one 250 mg EC capsule daily on an empty stomach*  or
one 125 mg wafer chewed or dispersed twice a day (consider two 125 mg wafers chewed once daily)

Wt. > 60 kg:    

one 400 mg enteric-coated capsule once a day on an empty stomach* or

two 100 mg wafers chewed or dispersed twice a day on an empty stomach*  or

two 200 mg wafers chewed or dispersed daily on an empty stomach*

*An empty stomach is defined as at least one hour before food or at least two hours after food

Possible exception: when used with tenofovir, this medication (Videx-EC)  may be taken with or without food

Diarrhea and GI upset common with wafer form

5-10% incidence of subclinical to rare fatal pancreatitis

Peripheral neuropathy - less common than zalcitabine or stavudine

Bad taste in mouth from wafer form of didanosine

Rare lactic acidosis and hepatic steatosis especially in setting of hepatitis C, ribavirin therapy, and concomitant stavudine

Didanosine may contribute to fat redistribution

Wafer form of didanosine lowers absorption of indinavir (see indinavir dosing below)

Wafer form decreases absorption of delavirdine

Tenofovir increases ddI levels: observe for ddI-related toxicity & reduce ddI-EC to 250 mg daily

Tenofovir and didanosine may produce mitochondrial toxicity and increased nephrotoxicity

Contraindicated with prior history of pancreatitis or elevated lipase / p-amylase

Contraindicated in moderate to heavy alcohol users.
Pancreatitis may be fatal.  Consider pancreatitis first in the differential diagnosis in patients on didanosine with compatible symptoms.

Avoid use with d4T/stavudine if possible
Rare lactic acidosis especially in persons with underlying liver disease: nausea, malaise, anion gap acidosis, renal failure, hepatic steatosis