Why am I taking a Headache Medication for My Depression?

A medication tends to retain the category name given to it based on the condition for which it was first used. This can be confusing when the medication comes to be used for another condition, or perhaps several other conditions. The reason the same medication may work for a variety of conditions is because medications do what they do in the body regardless of what we call them, and this biological effect in the body, known as the mechanism of action, may have a beneficial effect for a variety of different conditions. An example of a medication used for varying purposes is Depakote, which was first FDA-approved to treat seizures, then subsequently for Bipolar Disorder and Migraine Headaches.

Lamictal was also first developed and approved for seizures, then later became approved for Bipolar Depression. Sometimes the exact same medication is marketed under completely different names for completely different conditions. One example is fluoxetine, marketed as Prozac for Depression and Sarafem for a severe form of PMS called a premenstrual dysphoric disorder, or PMDD. Wellbutrin is the brand name for “bupropion” when used to treat Depression, and Zyban when used quit smoking. Wellbutrin is the brand name for “bupropion” when used to treat Depression, and Zyban when used to quit smoking.

A medication whose generic name is “guanfacine” is marketed as Intuniv for ADHD, and Tenex for hypertension (high blood pressure), even though in both cases, again, it is the exact same drug. There are also a number of medications used “off-label,” which generally means a common usage of a medication for a condition other than that approved by the FDA. Parenthetically, any medication approved by the FDA can generally be used for any purpose but can only be marketed by pharmaceutical companies for the FDA-approved indication.

FDA approval is a regulatory designation and does not always reflect how a medication is used in clinical practice. In fact, Trazadone, which is approved as an antidepressant, is much more commonly used for insomnia. In some instances, a single biological effect of medication accounts for its wide range of benefits; at other times multiple effects in the body account for a medication’s numerous benefits. From the examples above, boosting serotonin is probably a single effect accounting for the benefit of fluoxetine for depression (Prozac) and PMDD (Sarafem).

In the case of Trazadone, the serotonin effect accounts for the antidepressant benefit, but probably a combination of serotonin and antihistamine effects account for its sleep benefit. There are other medications initially approved for psychiatric conditions that come into more common usage for general medical conditions. An example of this is an older class of antidepressants, called the “tricyclic antidepressants” that are used by non-psychiatrists and psychiatrists alike for conditions associated with chronic pain, including Fibromyalgia. In this case, modulating serotonin and norepinephrine, two chemical messengers in the nervous system, has a beneficial effect on both conditions.

So, it’s a good thing medications ignore what we happen to initially call them, as they often turn out to help a variety of different problems!

Best Regards, Dr. Ranen (Psychiatrist Baltimore, Baltimore County, Owings Mills) DrNealRanenBaltimorePsychiatrist.com