Which category of drug is used as a last alternative for treating depression due to serious drug and food interactions?

The category of drug used as a last alternative for treating depression due to serious drug and food interactions is monoamine oxidase inhibitors (MAOIs). MAOIs work by inhibiting the enzyme monoamine oxidase, which breaks down neurotransmitters such as serotonin, norepinephrine, and dopamine in the brain. This leads to increased levels of these neurotransmitters, which can alleviate symptoms of depression.

However, MAOIs are often reserved for cases where other treatments have failed because they have significant interactions with certain foods and medications. For instance, consumption of tyramine-rich foods like aged cheeses and cured meats can lead to hypertensive crises when taken alongside MAOIs. Moreover, many common medications can interact negatively with MAOIs, leading to dangerous side effects. Given these risks, MAOIs are generally not the first line of treatment and are considered when other antidepressants—such as SSRIs or tricyclics—are ineffective.

Thus, the specific risks associated with drug and food interactions make MAOIs a last-resort option in the treatment of depressive disorders.