Failure of absorption of gabapentin after rectal administration.
OBJECTIVE
We wished to determine the extent of absorption of gabapentin (GBP) after rectal administration to children on maintenance therapy.


METHODS
Two children scheduled for extensive surgery received GBP rectally and orally. A pharmacokinetic profile was derived after each route of administration.


RESULTS
Serum GBP levels after rectal administration decreased at a rate similar to their rate of decrease after oral administration. However, GBP concentrations were much lower after rectal administration; therefore, we concluded that the aqueous solution was poorly absorbed rectally. The GBP half-life (t1/2) for the 2 children after oral doses were 4.2 and 4.8 h.


CONCLUSIONS
Rectal administration of GBP is not satisfactory when oral administration is interrupted. When oral GBP therapy is temporarily discontinued, clinicians should consider administration of alternative antiepileptic drugs (AEDs) that can be administered parenterally or rectally.
Kriel
R L
RL
Department of Pediatrics, Gillette Children's Specialty Healthcare, Hennepin County Medical Center, College of Pharmacy, University of Minnesota, Minneapolis 55415, USA.
Birnbaum
A K
AK
Cloyd
J C
JC
Ricker
B J
BJ
Jones Saete
C
C
Caruso
K J
KJ
D000085:Acetates / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D000284:Administration, Oral; D000285:Administration, Rectal; D000293:Adolescent; D000588:Amines; D000927:Anticonvulsants / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001682:Biological Availability; D002648:Child; D003509:Cyclohexanecarboxylic Acids; D004827:Epilepsy / Q000188:drug therapy* / Q000378:metabolism; D005260:Female; D000077206:Gabapentin; D006207:Half-Life; D006760:Hospitalization; D006801:Humans; D007408:Intestinal Absorption; D007413:Intestinal Mucosa / Q000378:metabolism; D008297:Male; D012007:Rectum / Q000378:metabolism; D005680:gamma-Aminobutyric Acid
D000085:Acetates; D000588:Amines; D000927:Anticonvulsants; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin