... bioavail-ability of an orally administered drug. 18 Drug Administration Lüllmann, Color Atlas of Pharmacology © 2000 ThiemeAll rights reserved. Usage subject to terms and conditions of license. Drug Administration ... of drug is undesirable, or when ab-sorption is being slowed in order to pro-long the action of drugs that have ashort sojourn in the body.10 Drug Administration Lüllmann, Color Atlas of Pharmacology ... affectedby drugs (atropine, antihistamines).14 Drug Administration Lüllmann, Color Atlas of Pharmacology © 2000 ThiemeAll rights reserved. Usage subject to terms and conditions of license. Drug Administration...