PEM report number 2. Terodiline

Abstract

AbstractPatients (12,457) who had been treated by general practitioners between November 1986 and September 1987 have been studied by Prescription‐Event Monitoring (PEM) for a period of one year. The events recorded on green forms were compared with those recorded in 14 other PEM studies. Nearly 5000 of the patients were aged 70 or more. The most frequent indications for terodiline were incontinence (43%) and frequency (18%). The most frequent daily dose was 25 mg (62%). NSAIDs had been coprescribed for 11% of the patients, tranquillizers for 10% and diuretics and analgesics each for 7%.The rates of events occurring during the first month of treatment with terodiline were compared with the mean rates recorded during the second to sixth month of treatment. This analysis was restricted to events experienced by more than one per 1000 patients during the first month of treatment. A ‘signal’ was noted when this rate exceeded the second to sixth month base‐rate by a factor of three or more or when the first‐month rate exceeded the pooled base‐rate for other drugs by a similar amount. All the well known side‐effects of terodiline were encountered. They included dizziness, blurring of vision, dry mouth, retention of urine and tremor. A number of other events were signalled, especially by the comparison with other unrelated drugs. Noteworthy were confusion, drowsiness and headache. Medical and surgical conditions such as urinary tract infection, bladder cancer or surgery to the genitourinary tract were also signalled in large numbers, but were clearly related to treatment with terodiline because they were part of the indications for its use.We studied certain groups of events with special regard to the patient's age and the dose of terodiline. Confusion was obviously related to old age but not to dose. Drowsiness, in contrast, was linked to high dosage, but not to age. Blurring of vision was very obviously related to high dose and was more likely to be complained of by patients under the age of 60 years. Tremor was no obviously correlated either with age or dose of terodiline. We have also investigated a possible relation between the calcium‐antagonist effect of terodiline and a number of cardiovascular events, including syncope, cerebrovascular accident and transient ischaemic attacks. These might have been responsible for some of the unusually large numbers of falls, fractures or other injuries noted in the terodiline series.The medical records of 1176 patients who had died were carefully studied and the cause of death was established in 94% of patients.We were able to quantitate the side‐effects listed in the data sheet for terodiline. Dizziness, dry mouth, constipation, visual disturbances and retention all occurred during the first month with a frequency up to 10 per 1000 patients. Nausea, cited as a rare event, occurred in 8.5 per 1000. PEM detected a number of other unlisted events as likely to be causally related including drowsiness, confusion and headache.