Blood pressure medicine works like any other medicine - until it wears off. Then it doesn't work anymore until you take it again.
This is a game that the pharmaceutical companies play whereby they can make money from unsuspecting idiots (no offense) who buy into their BS.
The fact is, your blood pressure will naturally return to normal if you would start drinking the water that your body needs. The pharmaceutical companies know this and this is why they've labeled every one of the body's symptoms of thirst "disease".
The pharmaceutical companies influence the medical profession and the medical schools. That's the reason doctors spend so much time (600 teaching hours) learning how to prescribe medicine and so little time (6 teaching hours) learning about nutrition.
Doctors don't advise to drink water like they used to, preferring, instead, to promote "fluids". That's because they don't understand the role of water in the body - they don't understand that water regulates everything in the body and it's because of a lack of sufficient water that people develop health problems.
It's also why their "salt causes high blood pressure" theory is wrong. They're putting the cart before the horse on this one and don't give the body credit for being able to take care of itself.
While it's true that we get too much salt in processed foods, we also get too much Dicalcium Phosphate, Riboflavin and many other nutrients found in food - but you never hear anyone advising to avoid these substances.
The body uses what it needs and discards the rest - it does this with salt, as well. The reason the body would hold onto extra salt is if it needed it. And the only reason it would need to hold onto salt is because of dehydration.
Of all of the nutrients the body needs, water is the only one you have to actually consume on its own. It's the one that gets depleted on a daily basis, and so it has to be replenished on a daily basis, as well.
Blood is 94% water. When you become dehydrated it loses 8% of its water volume causing it to thicken - and this blows the medical profession's "salt theory" out of the water (no pun intended).
If you were to start drinking the water you should and cut back (or avoid completely, preferably) you should see your blood pressure lowering to its normal levels within a week or less.
Do not avoid salt. You lose around 2 quarts of water per day through the body's normal functions - water that has to be replaced. Whenever you lose water you also lose salt. By avoiding salt you're ignoring the vest substance that holds water in the cells. You need salt - but it has to stay in a proper balance with water.
No matter what, do not stop taking any prescription medications on your own, no matter how your blood pressure reads. Reducing or stopping medication is your doctor's job and could be dangerous without his supervision.