We wished to determine the degree to which baclofen was absorbed from
an aqueous vehicle after rectal administration. A comparison was made
to absorption after oral administration. After oral administration, th
e baclofen half-life was 2.3 to 3.4 hours and peak serum concentration
s were achieved from 1 to 2.1 hours after administration. No measurabl
e absorption was observed after rectal administration of the drug in a
ny subject, Rectal administration of baclofen is not a clinically soun
d treatment option when oral administration of the drug is not possibl
e, For patients receiving chronic baclofen therapy, other medications
such as a benzodiazepine should be considered at times when oral admin
istration of medication is not possible. (C) 1997 by Elsevier Science
Inc. All rights reserved.