Pharmacokinetics of meptazinol after parenteral administration in the elderly.
We have determined the pharmacokinetics of meptazinol after its intravenous and intramuscular administration in a crossover study in 7 elderly hospital in-patients (greater than 70 years), and have compared with the results from 14 healthy, young volunteers (ages 20-40 years). The systemic availability after i.m. administration was comparable to that after i.v. administration, a result consistent with the physicochemical properties of the drug. There was a slight, but statistically significant (p less than 0.01) prolongation in t1/2Z in the elderly (mean 2.93 h) compared with the young (mean 2.06 h). This was associated with a 25% lower clearance in the elderly rather than with any alteration in volume of distribution. However, these changes would not appear to be substantial enough to require a revised dosage recommendation for meptazinol for this age group.
D000368:Aged; D000369:Aged, 80 and over; D001381:Azepines / Q000097:blood*; D005260:Female; D006207:Half-Life; D006801:Humans; D007273:Injections, Intramuscular; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D008621:Meptazinol / Q000008:administration & dosage / Q000097:blood*
D001381:Azepines; D008621:Meptazinol