Int J Pharm Pract 1997;5:81-4

Pharmacy Department, University of Port Elizabeth, PO Box 1600, Port Elizabeth 6000, Republic of South Africa
Ilse Truter, DCom, MSc, lecturer

Centre for Statistical Consultation, University of Stellenbosch, Republic of South Africa
Theunis J. van W. Kotze, DSc, chief statistician

Correspondence: Dr Truter

Original Papers

Variability of prescribed daily doses (PDDs) with respect to sex and age in the usage of simvastatin

I. TRUTER and T. J. van W. KOTZE

The variability of the prescribed daily dose (PDD) of simvastatin for different sex and age groups was investigated. Prescription data for 2,336 patients, on various medical schemes, who were using hypolipidaemic drugs on a chronic basis were analysed retrospectively over a one-year period ending on March 27, 1995. Most patients (62.5 per cent) on simvastatin were between 50 and 69 years of age. The average PDD of simvastatin was 12.6mg (12.5mg for females and 12.7mg for males). Average PDDs were in all cases lower than the defined daily dose (DDD) of 15mg, except for females aged 30 to 39 years. In almost all age and sex groups, a dose of 10mg was the median as well as the mode. The standard deviation of the PDD for females and males decreased after the age interval of 40 to 49 years.
Variation exists in the dosage regimen of most drugs, depending on a multitude of factors, such as the severity of the disease state, sex and age. This was also the case with simvastatin for this patient sample.