Example of non sedating antihistamine
The methods of prescription-event monitoring have been previously described in detail.5 In brief, the general practitioner writes a prescription which the patient takes to the pharmacist.
These questionnaires seek to determine any event experienced by patients while they were taking the drug and for a period afterwards.
Table 1 gives the age and sex distribution of patients treated with each antihistamine.
The demographics of each cohort were roughly similar.
To date, 65 prescription-event monitoring studies have been undertaken with a mean cohort size of 11 055 patients.
Prescription-event monitoring has various strengths and weaknesses.5 The method is non-interventional and does not interfere with general practitioners' decisions about the most suitable treatment for a patient.
Incidence densities were calculated for all of the events reported, to give an indication of which events were reported significantly more frequently in the first month of exposure.