H'evaoxYzmE (Atarax@, Vlstarll@) has been under ehmcal trial to determine its efllcaey for pre-anaesthetae medacaUon on the bas.~ of its purported ne~oseda~jve, antihistaminic, anhspasmodle, anta-emet~c, and anaesthellc potentaatmg properties ~4 Laboratory studies have shown that the intravenous mleetmn of hydr0xyzme causes a transmnt fall m blood pressure, an increase m coronary blood flow, and suppressmn of epinephrine-reduced ventrmula~l arr]hythmms 7 The pmtectare effect of hydroxyzme against arrhythmms is unrehable s In ehmeal tests, the therapeutic sedative dose has ~nrtually no antasml0gogue effect, 9 nor doe~s It chsturb the blood pressure even when circulatory stress of 60-degree head-up tilt is used t0 No undesirable side effects have been reported chmeally Promethazme (Phenergan@) has been used widely for pre-anaesthetm medacatlon dmmg the past ten years, ~x-~ paracularly when it as desirable to provade an antflustammm effect a7.~s It ~s a potent sedative, as deltermmed by the potentmi~on of ttnopental anaesthesm, s as a powerful antlslalogogue on account of its marked antxchohnerglc properties, ~9 ~0 and it has a mmmaal effect on the ctrculatory response to hlt 2~ The only drawback to ~ts routine u~e as the frequent complaint by patients of a "twltchy" feehng, whmh appears to be a common effeci of phenottnazme denvataves 2z 2~ Secobarbltal ~s a short-acting hypnotxc sedattve that has been used w~dely' for pre-anaesthet~e medmataon for many years It ~s recogmzed to be effective and has va-tually no undesirable effects, except that oceasmnally an elderly patient becomes confused during the half-asleep state that as reduced, whmh increases the ala~zn ff the patient as m an unfamflmr env~rorltment Tlh~s response as not uncommon w~th most of the barbiturate sedattves ~z Th~s report describes a double-bhnd study m whaeh hydroxyzme, secobarb~tal and a placebo (coded unlmowns) were compared w~th prornethazme (coded, but known) for pre-anaesthetac medmataon ~J[ETHODS Four hundred identical capsules were prepared of rwhlch 100 contained 50 mg ~From the
