Many people find worsening symptoms when they introduce a new drug. MAVers do tend to have an existing/or with chronicity develop strong hypersensitivity to a wide variety of things medication being but one. Therefore I’d say it’s pretty common though not acknowledged by many doctors I’m afraid so expect some strange looks. Checking our database I found this example.
1 month into Zoloft(Sertraline) Worse than when i started
In addition I checked it out and Sertraline is an SSRi. When I was prescribed an SSRI (Citalopram) my doctor told me to expect to feel a lot worse for at least three weeks before I might start feeling better. I’d suspect the same might apply. That is purely a result of the drug itself. VM once chronic can be intractable and difficult to get under control. It’s not clear why you were prescribed this drug but also be warned if it is to help your VM symptoms as a preventative it could easily 3-4 months to become effective. That applies to most commonly recognised preventatives and presumably (I’m not a doctor) relates to the condition itself.