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Biomedical subjects

D N Wade

Publications and source records attributed to D N Wade.

At least 55 records · Page 3Linked to original sources

The background pattern of drug usage in Australia.

The pattern of drug usage by urban populations has been studied in two typical Australian cities: Traralgon, Victoria, and Sydney, New South Wales. The study, lasting 1 year, involved questioning of 10% of the residents in households selected by random sampling and records of pharmacists. The questions related to state of health, recurrent or chronic disability, and drug exposures during 2 wk preceding the interview. Figures obtained from the Pharmaceutical Benefit Scheme (a system of partial federal subsidy) and the Morbidity Survey of the Royal Australasian College of General Practitioners showed Australians to be near the top of the world's drug takers, in comparison for example with Americans: between 6 and 7 prescriptions per capita in Australia and between 4 and 5 prescriptions in the United States in 1973. The consumption of over-the-counter drugs (OTC) was estimated from the Commonwealth Statistician's figures by subtracting the expenditure for prescription drugs from the total annual chemist sales--$A450,000,000. This represents a cost of $A33.85 for every man, woman, and child. Of this amount $A19.07 was spent for OTC drugs, analgesics and cough suppressants being the two largest items. Roughly 60% of Australians average two or more doses of analgesics per day, with some patients consuming 12 or more doses a day. An association between this high consumption of analgesics and an alarming incidence of iatrogenic disease--analgesic nephropathy and gastrointestinal hemorrhage--is postulated. It is concluded that this level of drug usage must be symptomatic of underlying stresses and pressures of urban society in that country, along with a cultural factor of ready acceptance of the social use of drugs.

Adolescent↗

Effects of tricyclic antidepressants on drug metabolism.

The effects of chronic treatment with amitriptyline and nortriptyline on the elimination from plasma of warfarin, dicumarol, phenytoin, and tolbutamide were examined in man. No alteration of plasma half-life of warfarin, phenytoin, or tolbutamide was observed following dosage with the tricyclic antidepressants used. There was no consistent effect on the metabolism of dicumarol following treatment with amitriptyline or nortriptyline although the bioavailability of dicumarol appeared to be increased. In some subjects, this increased bioavailability was associated with significant prolongation of the plasma half-life of dicumarol due to its dose-dependent kinetics.

Adult↗

The role of the liver in the clearance of l-dope from plasma.

The role of the liver in the plasma clearance of l-dopa in the rat was examined. Some published studies which ascribe an important role to the liver in l-dopa clearance are discussed and critically evaluated. Contrary evidence suggesting that the liver is not a significant site of l-dopa clearance in vivo is presented. The plasma concentration of l-dopa during intravenous infusion of the drug was not significantly reduced after a single passage through the liver. All of the data discussed are consistent with the conclusion that the liver plays a minor role in l-dopa clearance in vivo. It is suggested that the small intestine is the major site of metabolism of orally administered l-dopa.

Animals↗

The effects of allopurinol and clofibrate on the elimination of coumarin anticoagulants in man.

The effects of chronic treatment with allopurinol and clofibrate on the elimination from plasma of warfarin and dicoumarol were examined in man. In addition, the binding of warfarin to human serum proteins was measured with and without clofibrate and its metabolite chlorophenoxyisobutyric acid (CPIB), both present in therapeutic concentrations. Treatment with allopurinol and clofibrate did not alter the rate of elimination of warfarin from plasma. In addition, clofibrate and CPIB caused no significant displacement of warfarin from serum proteins. This evidence supports the conclusion that the clinically significant potentiation of warfarin activity by clofibrate in man is due to an interaction at the receptor site. In contrast, treatment with allopurinol resulted in significant prolongation of the plasma half-life of dicoumarol in one of three subjects. These data are consistent with inhibition of the metabolism of dicoumarol by allopurinol in some individuals.

Adult↗