Influence of age and previous use of diazepam dosage required for endoscopy
Giles, H.G.; Macleod, S.M.; Wright, J.R.; Sellers, E.M.
Canadian Medical Association Journal 118(5): 513-514
1978
ISSN/ISBN: 0008-4409 PMID: 630512 Document Number: 131478
In 19 patients (10 men and 9 women) a 22-fold variation was observed in the i.v. dose of diazepam necessary as preparation for endoscopy (median dose, 20 mg; range, 5-110 mg). Analysis of plasma samples for diazepam and N-desmethyldiazepam revealed that the clinical response did not relate to the rate or character of initial drug distribution. There was a high correlation (r = 0.96) between the dose and the plasma concentration 10 min after administration. Users of diazepam displayed tolerance to its pharmacologic effects, requiring a significantly larger (P < 0.05) dose than nonusers (median doses, 35.0 mg and 14.5 mg, respectively). Older patients required less than younger patients (r = -0.54, P < 0.05). The variation between individuals in the dose of diazepam required as preparation for endoscopy cannot be explained by variation in drug disposition but instead reflects previous diazepam use, age and probably differences in sensitivity at the site or sites of drug action.