Thanks Onwards for sharing this...I think this actually just happened to me a few hours ago. I never take 400 mg at once and I forgot I took 200mg and took another 200,,,and boy did I feel it...BP went from 112/70 to 94/ 40...I had to take a lttle salt and rest and it came back..I was so busy after shopping and workin in the yard I was not paying attention..I will be now..
Marie :)
PS. sometimes take 400 mg at bed time with no issues ...