Hello, both Losartan
) belong to the same group of antihypertensive drugs ( drugs used in high BP
). They are angiotensin
receptor antagonists. These drugs block the receptor to which angiotensin-2 gets attached to, & prevents the vasoconstrictor action (contraction of blood vessels) of angiotensin. This results in fall in BP.
No drug used in the treatment of BP should be stopped suddenly as that will remove the control of the drug on blood pressure resulting in sudden (acute) rise in BP. Losartan when stopped suddenly results in dizziness
Dose wise Olmesartan is more potent than Losartan (ie., 20 mg of Olmesartan is equal to 50 mg of Losartan). Also the effect of the starting dose of Olmesartan is higher than the effect of starting dose of Losartan . So if you had taken the similar strength of Olmesartan (the same dose of Losartan you were taking) it will result in greater fall of BP causing dizziness. And, one of the frequent side effect of Olmesartan is dizziness. So the dizziness you are experiencing could be due to
1. sudden failure in taking Losartan.
2. higher starting dose of Olmesartan resulting in greater fall of BP.
3. side effect of Olmesartan due to high dose.