Drugs may affect gastrointestinal motility and, therefore, absorption of other concomitantly administered drugs. Gastrointestinal prokinetic agents increase the rate of gastric emptying and also upper intestinal motility. These effects would be expected to increase the initial rate of absorption of orally administered drugs, but reduce total bioavailability of the agents. Metoclopramide has been shown to increase the rate of absorption of several classes of drug, reflected by reduced time taken to achieve maximal plasma concentration (tmax) and increased maximal plasma concentration (Cmax). However, the effect of these agents on the area under the plasma concentration-time curve from zero to infinity (AUC0-infinity), when measured, is not consistent. Cisapride and domperidone appear to have similar effects, but there are relatively less data available regarding these products. Opioids may delay gastric emptying considerably, an effect which will often have significant clinical and therapeutic implications. Most of the data confirming this observation concern oral analgesics, but the effect should be considered when prescribing any oral medication. Drugs with anticholinergic or sympathomimetic activity are likely to have a similar effect and this is confirmed, in the main, by the limited data available. Although many effects reported in the literature are of limited clinical importance, they may be significant when prescribing a drug with a narrow therapeutic index, especially if it is absorbed poorly.

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We present a case of abdominal aortic aneurysm repair using a new technique of aortic stenting and discuss the anaesthetic technique used and the perioperative advantages of the technique.

1 Cholinergic neurones in the basal forebrain are linked to cortical activation and arousal. 2 The present study was designed to examine the hypothesis that clinically relevant doses of halothane (0.1 to 5%) would significantly reduce depolarization-evoked acetylcholine (ACh) release from rat cortical slices. 3 ACh release was measured from rat cortical slices by a chemiluminescent technique. 4 Depolarization-evoked ACh release was inhibited significantly by halothane with an IC50 of 0.38%. This value equates to 0.3 MAC (the minimum alveolar concentration at which no movement occurs to a standard surgical stimulus in 50% of subjects) for the rat. 5 The potent effect of halothane on ACh release suggests that this mechanism may be a target for the action of volatile anaesthetic agents. This in vitro effect on ACh release is consistent with effects of halothane reported in vivo.