Can Polypharmacy in Psychiatry Be Rational?
For polypharmacy to be rational, the prescriber in any area of medicine must be able to answer the following questions: 1. Why am I using more than one drug? 2. Do the drugs interact? 3. If so, what are the data that support the safety, tolerability, and efficacy of the combination? Table 13 lists five major reasons why a prescriber may use more than one drug to treat a patient.59,81 The first reason is the most obvious: The patient has more than one disease process and the prescriber must employ one or more agents for each disease. In this example, the prescriber is not planning a DDI, though one may occur because drugs interact on the basis of the mechanisms underlying their pharmacodynamics and pharmacokinetics rather than on the basis of their therapeutic indication. For this reason, the prescriber of psychiatric medications must be aware of and consider all of the medications the patient is taking. The second reason listed in Table 12 is particularly relevant to psychiatry.59,81 C
