Different drug stereotypes for antipsychotics
Table 1 summarizes results from drug utilization studies on physicians' drug stereotypes for olanzapine(Drug information on olanzapine), risperidone(Drug information on risperidone), and amisulpride(Drug information on amisulpride).15,20,21 It shows the most important reasons for switching to or selecting these drugs.
In the view of treating physicians, the use of olanzapine is characterized by an expectation of high efficacy and good tolerability. However, problems associated with olanzapine include weight gain and high cost.
Amisulpride is seen as an effective antipsychotic with special benefits for the treatment of negative symptoms. It is seen as having good tolerability not only in regard to extrapyramidal symptoms (EPS) and weight gain but also in respect to sedation, cognitive impairment, and its efficacy for quality of life.
When contrasting risperidone and amisulpride, physicians report differences in tolerance for negative symptoms and EPS, and efficacy for subjective well-being. When contrasting olanzapine and amisulpride, practitioners see differences in efficacy in treating negative symptoms, weight gain, and subjective well-being. Such drug stereotypes can be further extended by analyzing the reasons for or against switching to another drug.
The data show that prescribers not only see differences between conventional or classic antipsychotics and modern or atypical antipsychotics but also between different medications within the class. There are obviously special associations attached to each drug. The data also show that drug stereotypes of physicians correlate with scientific knowledge of these compounds.
RATIONAL CRITERIA TO SELECT OR CHANGE TREATMENT
In terms of switching antipsychotic medications, what can be learned from research on medical decision making and drug stereotypes? It is impossible to say which drug should be selected under every scenario because the variety of clinical circumstances, patients, and treatment options is too large to give definite recommendations.
Many traditional guidelines refer to theoretical knowledge only, without offering guidance on how to incorporate the information into experiential and situational knowledge. Instead, recommendations should focus on how to guide decision processes (ie, which questions to ask when) that, in contrast to traditional prescriptive treatment guidelines,22-28 can be called operational guidelines.8,16 Such guidelines inform physicians how to proceed when trying to solve a treatment problem, including consensus on goals, values, and emotional preferences. Drug advertisers are obviously aware that drug stereotypes and emotional aspects are important factors in medical decision making by treating physicians.
The guideline for the treatment of schizophrenia as published by the National Collaborating Centre for Mental Health (NICE)29 takes into account the multidimensionality of the medical decision making processes. Not only does it refer to prescriptive theoretical knowledge (eg, "if a conventional antipsychotic is chosen: use 300 to 1000 mg chlorpromazine(Drug information on chlorpromazine) equivalents per day for 6 weeks") but it also incorporates situational knowledge (eg, "if unacceptable side effects emerge with a conventional antipsychotic then consider an atypical antipsychotic"). It also takes into consideration attitudes and anticipations of physicians and patients (eg, "have full discussion about preferences of service user").
Using the NICE guideline and our own observations in routine care, the decision rules presented in Table 2 were formulated to help treating physicians make wise decisions when switching antipsychotics. Physicians should ask questions in a stepwise manner. Deciding which question to ask first can be based on empirical evidence, values, or procedural considerations.
Is switching needed?
This question can almost never be answered with certainty. If a patient is in a stable condition but not in full remission, as in most patients with schizophrenia, one hypothesis is that another drug may be more effective. The alternative hypothesis is that changing the present drug will lead to a deterioration of the stable status. Harm may result from either action or nonaction. The same is true when the patient is unstable or is spontaneously deteriorating.
Switching medication therefore depends on the personality of the physician. An active physician should avoid the temptation to do too much; a more hesitant physician should not forget to take an active approach in the treatment plan. The treating physician should remember to review the medication plan at least once a year.