Occasionally, doctors will have a patient who requires the use of multiple medications in order to best manage their care. I have had patients such as this, and the situation is not unusual. We call this practice “polypharmacy.” Let me explain how it works and why it can be necessary.
What is polypharmacy?
Polypharmacy is the term used to describe the prescription of a number of psychotropic medications simultaneously. (A psychotrophic drug is a psychiatric medication that alters chemical levels in the brain, thus affecting mood and behavior.) Polypharmacy generally involves a mixture of medications from different categories. When practiced correctly, it involves a step-by-step, logical approach towards treating targeted symptoms. With today’s newer and safer medications, it is becoming more common for psychiatrists to use a polypharmacy approach when a patient may see significant benefits from such treatment.
How does it work?
Polypharmacy generally involves the use of medications that have different neurotransmitter profiles. The goal is to cover one neurotransmitter system, allow time to assess the effectiveness of the treatment for that symptom, then once that is stable, add another medication which works on a different neurotransmitter. Although a person may end up taking multiple medications, each one has a unique effect, has limited overlap with the other, and has limited drug interactions.
Why is polypharmacy affective?
At times, an added medication may be used to increase the effect of a medication that is already being prescribed. For example, the traditional approach for treating a client with major depression would be to prescribe an antidepressant. Usually, this would be an antidepressant with a potent serotonergic effect (an SSRI). (A serotonergic effect is one that boosts feelings of well-being and aids in re-establishing normal sleep/awake patterns.) If this doesn’t work, the psychiatrist may change antidepressants, or he may add an antidepressant that increases dopamine and norepinephrine activity. (Increasing dopamine can improve mood as well as foster increased brain function and alertness.) In this case, two antidepressants are used simultaneously, but each works in a very different way.
Sometimes, an antidepressant alone is not enough; in those cases, the doctor may add on medications from other families of medicines. If anxiety is another predominant symptom, then Klonopin or Ativan may be added, or a medication that enhances the effect of the SSRI.
If the patient complains of intolerable mood swings, then a mood stabilizing medication may be added. If a patient has psychotic symptoms, or requires a stronger medication for mood stabilization or relaxation, then an antipsychotic medication could be added. Today, most doctors prefer using antipsychotic medications from the “atypical” class. While these are more expensive, they have superior safety profiles to older “typical” antipsychotic medications, with far fewer side effects.
Therefore, patients with difficult-to-treat psychiatric illnesses may be on a number of medications simultaneously. Each medication will represent a different class and will involve a different mechanism in terms of how it is used by the body. The more common polypharmacy regimens may involve one antidepressant, one mood stabilizer, one antipsychotic, and one anxiolytic.
In summary:
Polypharmacy must reflect a well-thought-out strategy by the physician. This strategy needs to address target symptoms, how each drug will work, the patient’s metabolism and ability to handle the medications, the potential for drug interactions, and possible side effects. When all are taken into account, and a carefully balanced plan is put into place, there can be significant benefit to the patient. 
