Tapering Off One SSRI to Start Another is Like Making a Gradual Switch Between Beer Brands
I sometimes see even supposedly seasoned clinicians taper a person off one SSRI like escitalopram (Lexapro) and then starting from scratch with another SSRI like sertraline (Zoloft).
In my experience, this is almost never necessary. Think about it, the SSRIs hit the same receptors. Each drug has a somewhat different personality; some are sedating, some a little energizing and so on. You would also have to consider the half life, like fluoxetine (Prozac) has a long one and venlafaxine (Effexor) a short one. Switching between a long acting and a short acting one may require a wait period or a partial taper. But the main action is similar enough that tapering completely off one and on to another is more likely to cause unpleasant reactions (SSRI withdrawal) than a straight one-day switch. I do the same when switching from an SSRI to an SNRI like venlafaxine or duloxetine. I just ballpark the SSRI potency of the two drugs and, wham, we’re done.
So, as long as you hit the same receptor, it’s not a whole lot more complicated than going from Corona to Bud Light. You might want to consider the potency, and to some degree the drug half life, but it’s not quite rocket science.