If your husband’s blood pressure is dropping his blood pressure medication needs to be closely monitored. It is possible that it will need to be lowered. It is possible for his blood pressure to go too low and to risk passing out. Your husband should discuss these concerns with his health provider. He can also purchase a blood pressure cuff for in home use so he can monitor his own blood pressure.

My husband has orthosatic hypertension we did have to tweak his BP meds due to that as with Parkinson’s it tends to affect their BP like that.

Has his diet changed? Is he less stressed?

Has he also been loosing weight over time? That could also cause a lowering of BP. Would be good to check and record his BP rice daily for the doctor to get an idea of fluctuation.

See your family dr take his blood pressure standing and sitting it's the meds interjection with each other