Why Do Psychiatrists Select or Switch an Antipsychotic?

The investigation of medical decision making, which includes drug selection and drug switching, is of high importance because it pertains to quality assurance, the development of treatment guidelines, and the understanding of treatment processes. The increase in diagnostic and therapeutic options has made the selection of the best medical strategy more complex. Physicians are often forced to work and make decisions under time pressure, which complicates matters.

The treatment decision is not only dependent on the type, severity, and course of the illness but also on the patient's preferences, his/her adherence to treatment regimens, and a variety of contextual factors, such as availability of treatments or possibilities of surveillance.^1-6 Medical decision making can be understood as a problem-solving process. It aims at selecting the best of several alternatives while weighing advantages and disadvantages^6-11 and making estimates on prognosis and therapy.⁸

For the description of complex decision-making processes, one can refer to the action theory that describes how everyday decisions are made.^12-14 This theory can also be used as a theoretical framework for the analysis of drug selection and drug switching. It distinguishes several steps of action: (1) action planning, which is based on theoretical knowledge, experiential knowledge, assessment of the situation, and anticipations; (2) decision making, which includes the development of an intention, emotional assessment, and goal setting; and (3) operation, which refers to the implementation of action, effect control, and feedback.¹⁴

REASONS FOR DRUG SELECTION OR SWITCHING

A method for examining action planning is to ask physicians for their reasons for selecting a particular treatment, which can be done using the Reasons for Treatment Selection Questionnaire (RTSQ) (Figure).⁸ The RTSQ allows a treating physician to investigate the reasons why he favors a certain drug, switches from one drug to another, or continues the present treatment. Based on the action theory, the questionnaire assesses:

• Theoretical knowledge: awareness of recent empirical findings (eg, no. 2)
• Experiential knowledge: personal experiences with a certain treatment (eg, no. 1)
• Situational knowledge: knowing that a patient does not tolerate a specific treatment (eg, no. 5)
• Attitudes and anticipations about the course of therapy (eg, no. 11)
• Interactional knowledge: knowing what the patient prefers (eg, no. 4).

These categories are understood as latent constructs that have a combined influence on medical decisions. They contribute to the understanding of why a physician prescribes a certain drug in a certain case at a certain moment.^8,14

Positive or negative expectations of a particular drug can be called "drug stereotype." This determines when a drug is prescribed.¹⁵

Knowledge of drug stereotypes is important in order to understand how medical decisions are made, to ensure quality of treatment, and to monitor advertisements and costs.¹⁶ Drug stereotypes that a physician has can be compared with his familiarity with pharmacological data and knowledge of prescribing trends. Discrepancies indicate a need for changes in how physicians are informed about a drug and/or the benefit of further studies to clarify whether practitioners have experience with the medication that has not been addressed in research.¹⁵ Drug stereotypes can be investigated in observational drug utilization studies.^17-19

Different drug stereotypes for antipsychoticsTable 1 summarizes results from drug utilization studies on physicians' drug stereotypes for olanzapine, risperidone, and 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 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.

Is the present treatment working?
One view is that the physician's priority should be to help the patient overcome the illness. Others may decide that the priority must be to not harm the patient. This is a value decision. To help guide the physician's course of action, we must remember the rule: do everything possible to help the patient. When putting effectiveness first, the present illness status and, more important, the course of the current treatment has to be taken into account. If the current treatment has led to some progress, it should be continued unchanged.

Whatever the treatment strategy may have been-older or newer antipsychotics, low or high dosage, 1 drug or multiple medications-if it works, it is okay. No theoretical reason should make a physician change a successful treatment. If there is no convincing progress, the next step is to make sure that the medication is being taken as prescribed. One cannot argue that a drug did not work if it has not been used correctly. Double-check and correct dosages (ie, are they too high or too low), treatment duration, and patient adherence. If the present illness status has not improved in spite of an appropriate antipsychotic medication, do not wait, test something else and switch to another medication.

Is the current treatment tolerated?
Physicians should not harm patients (nil nocere). Negative drug effects have to be taken seriously and should be minimized as much as possible. Look for and ask about signs and symptoms of known adverse effects. Inquiring about adverse effects does not increase their prevalence, nor does it lead to nonadherence. Instead, the patient gets the feeling that the physician cares about his progress and well-being.

If there are adverse effects, the question is whether something can or must be done. Serious adverse effects that can cause severe harm (eg, tardive dyskinesia) must lead to a change in treatment, whether the patient likes the change or not. Subjective burdensome side effects should not be played down but should lead to a change in treatment whenever it is medically possible. Medical considerations should come first but don't forget to empathize with your patient.

Which drug should be selected next?
After the decision has been made that a change in medication is needed, the physician must decide which drug should be tried next. Factors listed in the RTSQ⁸ that should be considered include patient preferences, pharmacological profiles, drug interactions, potential side-effect profiles, costs, application modes, illness status, special drug effects, social and occupational status of the patient, recommendations by superiors, colleagues or others, and experience with the drug. Again, value judgments are necessary to determine what factors are most important. We think that in most cases the decision should start with consideration of the side effects.

This leads us to another rule:use rehabilitation pharmacotherapy and support participation. By and large, all antipsychotic medications are equally effective.^30-33 However, there are relevant differences in respect to their side-effect profiles. Adverse effects are not only a medical problem, they also have consequences for participation in social or occupational life. For instance, sedation impairs working ability, impotence impairs connubial life, emotional flattening impairs social interaction, and weight gain impairs general health and self-confidence. All patients have special needs and individual problems. Rehabilitation pharmacotherapy,³⁴ a new way of prescribing that aims to increase participation in social life in addition to (and perhaps even more than) reducing illness symptoms, takes all these factors into consideration.

Another important aspect is the patient's cooperation. Like most physicians, most patients have their own preconceived notions about certain drugs. They may also prefer different modes of application. The general rule should be to fulfill the patient's wishes whenever medically possible (treat your patient as if he were your client).

CONCLUSION
Pharmaceutical companies and scientists love to point to new developments, and it is their job to do so. They thus recommend new drugs more vigorously than older ones. They highlight their new pharmacological, side-effect, or efficacy profiles. They bring new literature to every physician desk and stimulate scientific debates on special aspects of new drugs. They even include these discussions in treatment guidelines.

Experienced physicians know that medical progress in antipsychotics has moved at a snail's pace and that many promises turn out to be empty or simply wishes and good intentions. Therefore, it is wise to stay with well-known drugs and not hop on the bandwagon of every new drug. It is also wise to use the same drug in most patients instead of using different drugs in each patient. Only by repeated prescribing is it possible to become thoroughly acquainted with a drug. Thus, it is wise to choose the drug that you have prescribed most often and with which you are most familiar.

Last but not least, physicians should be aware that they spend the money of other persons. Whenever possible they should help to reduce costs.