When MAOIs are used with SSRIs, what is the recommended washout period?

• A. They can be taken together safely with monitoring
• B. A 1-week washout is sufficient
• C. SSRIs should not be given within 2 weeks of MAOIs
• D. There is no interaction between MAOIs and SSRIs

Answer: (C)

The key idea is that combining an MAOI with an SSRI can push serotonin levels too high, risking serotonin syndrome and dangerous blood pressure changes. MAOIs irreversibly inhibit the enzyme that breaks down serotonin and other monoamines, so after stopping an MAOI, the body needs time to produce new MAO enzymes. That recovery takes about two weeks, which is why a washout period of roughly fourteen days is recommended before starting an SSRI. In some cases, especially with drugs like fluoxetine that have a long half-life, the washout may be longer, but the standard guidance is at least two weeks between stopping an MAOI and starting an SSRI. Therefore, starting an SSRI within two weeks of an MAOI is not advised.