Hydrochlorothiazide
"Worked for me by day 2, my bp now 125/76. I had been on a calcium channel blocker (amlodipine (Norvasc)) for 9 years, & my hair had thinned so badly, when I finally found out that hair loss is a known side effect of amlodipine,  I barely took the medication anymore, I started going to a new doc, who was surprised that my previous doc had not tried a diuretic before putting me on a calcium channel blocker, she started me on 25 mg, and told me to take it in the morning, & eat foods with lots of potassium to avoid cramping in my muscles, & drink water because I was probably going to start feeling dehydrated, with a headache. I followed her directions, & after feeling slightly nauseous the first couple of days, feel great."