Single-dose pharmacokinetics of enteric-coated didanosine in HIV-infected children.
Didanosine remains a cornerstone nucleoside analogue for the treatment of HIV infection. A potential problem with the buffered formulations of didanosine is the likelihood of interactions with other drugs that require an acidic pH for absorption or can be chelated by cations in the buffer. An encapsulated enteric-coated (EC) bead formulation of didanosine has been approved and is routinely used as an alternative to the chewable/dispersible buffered tablet formulation. The objective of this study was to evaluate the single-dose pharmacokinetics of didanosine EC at 240 mg/m2 in 10 HIV-infected children. Didanosine EC was administered at time 0 on an empty stomach with no other concomitant medications. Blood samples were collected at pre-dose, 0.5, 1, 2, 4, 8 and 12 h post-dose. Didanosine was measured in plasma using radioimmunoassay. Ten subjects completed the intensive pharmacokinetic evaluation; data are available for eight participants. Plasma concentrations of didanosine following EC administration were analysed using non-compartmental methods. Median (range) AUCinfinity, Cmax, Tmax and CL/F for didanosine following EC administration were 2385 (1291, 3966) ng x h/ml, 854 (300, 1799) ng/ml, 3.0 (1.0, 8.1) h and 3.3 (2.7-6.4) l/h/kg, respectively. Results from this study indicate that the didanosine Cmax is decreased and Tmax is prolonged, but total exposure of didanosine in plasma following didanosine EC administration appears similar to previous data collected in HIV-infected children following buffered didanosine administration.
King
Jennifer R
JR
The University of Alabama at Birmingham, Birmingham, Ala., USA.
Nachman
Sharon
S
Yogev
Ram
R
Hodge
Janice
J
Aldrovandi
Grace
G
Damle
Bharat
B
Smith
Elizabeth
E
Wiznia
Andrew
A
Acosta
Edward P
EP
D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics; D019540:Area Under Curve; D002626:Chemistry, Pharmaceutical; D002648:Child; D002675:Child, Preschool; D016049:Didanosine / Q000008:administration & dosage* / Q000493:pharmacokinetics; D005260:Female; D015658:HIV Infections / Q000188:drug therapy*; D006801:Humans; D008297:Male; D013608:Tablets, Enteric-Coated
D019380:Anti-HIV Agents; D013608:Tablets, Enteric-Coated; D016049:Didanosine