Rational and Irrational Polypharmacy

To the Editor: I appreciated the thoughtful column "Rational and irrational polypharmacy" by Kingsbury and his colleagues in the August 2001 issue (1). However, for the benefit of individuals targeted by the conscientious malpractice attorneys who may have read the article, it should be said that there are factors that contribute to what might appear to be "irrational polypharmacy" other than those cited in the column, which include fear, laziness, sloppy diagnoses, botched cross-titrations, magical thinking, inadequate knowledge of receptor pharmacology, and blind adherence to recommendations listed in the Physicians' Desk Reference.

It is generally acknowledged that some patients have illnesses that are refractory to all known antipsychotic agents. In such circumstances, it is not unusual for psychiatrists to use more than one antipsychotic agent, although the authors cite the use of "several antipsychotics at the same time" as an example of irrational polypharmacy.

Psychopharmacology is not an exact science. Even drugs in the same pharmacological class do not have exactly the same receptor-blocking profiles. Psychiatrists and other physicians vote with their feet. They will walk toward whatever combination works. They will walk away from regimens that do not work. This has nothing to do with fear or laziness. It has to do with pragmatism.

For some patients, such apparently irrational treatment has worked better than any previously constructed approach based on rationality. Improvement can occur for unknown reasons, but when it does occur, the reasons underlying the effectiveness of an apparently irrational approach are generally worked out later, after the fact. Such fortuitous events are not unheard of in the process of treatment; indeed, serendipity has always had a prominent role in medicine.