I've been prescribed 7.5mg of mirtazapine. i had a severe blackout because of it. i have a history of hypotension. should i visit my gp to change drug?

Yes: Not knowing how long you've been on the medication or the details of your syncopal episode, it would be best to call your doctor as soon as possible and describe your side effects before making any medication changes yourself.

Yes : Once an adverse reaction to a medication occurs it is important to contact the prescriber asap.

Yes : You should always discuss side effects and response with your physician. If you have a history of hypotension how do you know it was the Buspar (buspirone) that caused the black out and not the hypotension? Definitely talk with your physician.