US EPA

1619793 

Technical Report 

Pharmacokinetics of propallylonal (Noctal) 

Beyer, KH; Duchstein, WD 

1981 

IPA/82/486311 

Apoth 

REF 13 

2308-2312 

IPA COPYRIGHT: ASHP The pharmacokinetics of propallylonal (5-acetyl-5-isopropyl-barbituric acid; Noctal; I), and the influence of phenobarbital (Luminal; II) on the metabolism of I, were studied following the oral administration of one tablet of 200 mg I to a healthy volunteer, and one tablet of 100 mg II for 10 consecutive evenings, followed by one tablet of 200 mg I on the 11th evening, to another healthy volunteer. In both cases, 24 hr urine was collected until it was clear of the drugs or their metabolites. Results showed that an average of 5.16% of I was eliminated within 7 days; the metabolite, 5-acetonyl-5-isopropyl-barbituric acid was excreted over 9 days at an average amount of 20.49%. Pre-treatment with II caused an enzymatic induction which reduced the total elimination time of I to 5.07% within 2 days and its metabolite to 20% within 3 days, while the total eliminated amounts of both compounds together remained almost constant. The qualitative and quantitative analysis of I in the saliva by gas chromatography was also undertaken. The quantitative detection was used to estimate the biological half-life of I. Results led to the same value of 2.7 hr. 

Propallylonal; pharmacokinetics; metabolism; Phenobarbital; effects; propallylonal; 5-Acetonyl-5-isopropyl-barbituric acid; metabolites; propallylonal; Metabolism; metabolites; Excretion; metabolites; Saliva levels; half-life; Half-life; saliva levels; Chromatography; saliva levels; Sedatives and hypnotics; pharmacokinetics; propallylonal(Sedatives and hypnotics; effects; phenobarbital(Sedatives and hypnotics; Drug interactions; phenobarbital and propallylonal; effects; propallylonal and phenobarbital; Luminal; Noctal; HUMAN