An adverse reaction unit: results and functions

Risk factors for adverse drug reactions--epidemiological approaches

Age by itself is not an important risk factor for ADRs. Age-related changes are the consequence of a number of individual factors, for example morbidity associated with polypharmacy, decline in renal or liver function in the elderly, hypoalbuminaemia, reduced body weight, etc. The relationship between gastrointestinal bleeding and non-steroidal anti-inflammatory drugs can be assessed globally in large cohort studies with access to computerized data, but complete accuracy requires access to the original patient records. The increase in the risk of GI bleeding in users of NSAIDs and aspirin was 50% above that in non-users. About a quarter of ADRs in hospitalized patients seem not to arise from purely pharmacological mechanisms. They are mainly due to allergic, anaphylactoid, or idiosyncratic reactions and to intolerance. In such non-pharmacological reactions, the time of exposure, reaction time, and even dosage may be important factors in identification of the causal drug. The use of benzodiazepines can be optimized by taking into account potency, time of action and the different syndromes encountered after withdrawal. Following long-term use problems of relapse and rebound are being increasingly recognized, in addition to organic withdrawal symptoms. In psychiatric patients extrapyramidal disorders due to neuroleptics are common. The rates of these ADRs differ markedly between various drugs, even after dosages and co-medications are taken into account. Epidemiological screening for potentially carcinogenic drugs can only be done in large cohorts of patients with pre-recorded full information sets as may be found in an HMO (Health Maintenance Organization). The findings of several such studies have been published in specialist cancer journals.(ABSTRACT TRUNCATED AT 250 WORDS)

Extrapyramidal symptoms in neuroleptic recipients

Adverse drug reactions (ADRs) in psychiatric therapy were continuously assessed in the AMUP study (AMUP = Arzneimittelüberwachung in der Psychiatrie (drug surveillance in psychiatry] conducted at two psychiatric university departments in the F.R.G. The Intensive Drug Monitoring (IDM) method was used to monitor 1107 patients, 754 of whom received neuroleptics (NLs). As is the rule in clinical psychiatric practice, polypharmacy was frequent, with combinations of two neuroleptics and combinations of a neuroleptic and an antiparkinson drug ranking first and second, respectively. Extrapyramidal motor symptoms (EPMS) were observed in 35% of the NL patients. In most cases they required a change in medication, usually addition of an antiparkinson drug. In about one quarter of all EPMS cases, withdrawal of the imputed NL was necessary. Parkinsonism was the most frequent single symptom, followed by acute dystonia and akathisia. Differences in EPMS rates between the two most frequently used neuroleptics, haloperidol, a high-potency butyrophenone, and perazine, a medium-potency phenothiazine, were distinct. EPMS were observed with haloperidol in 56% and attributed to haloperidol alone in 92% of these cases. With perazine, an EMPS occurred at a rate of only 14%, and in 37% of the cases EMPS were attributable to perazine in combination with other NLs. Age, sex, diagnosis and dosage of administered NLs were closely interrelated. For instance, NL patients over 60 years of age were almost exclusively female, the majority of them being endogenous depressives, whereas in younger patients the diagnosis of schizophrenia prevailed. Therefore, analysis of potential risk factors for development of EPMS must simultaneously include diagnosis, sex and age as well as concomitant physical disease, duration and dosage of all drugs administered before development of EPMS. However, the small case numbers in some subgroups, as we found them in this study based on everyday clinical practice, will probably be a limiting factor in such multivariate analyses.

A "new" drug for treating agitation and psychosis in the general hospital: chlorpromazine

Psychiatric residents on a consultation-liaison service consistently avoid chlorpromazine in favor of haloperidol for the treatment of psychotic, agitated patients. The residents' fears of chlorpromazine as a dangerous medication are presented and the literature about chlorpromazine's side effects is reviewed. Evidence was not found to support the contention that chlorpromazine is too dangerous to use in the medical setting. Case material illustrating the benefits of chlorpromazine is presented. A theoretical explanation for the observed prescribing practices is suggested.