Q. is a directly acting vasodilator, but is not used alone as an antihypertensive because: (Solved)
1. By itself, it is a low efficacy antihypertensive
2. Effective doses cause marked postural hypotension
3. Tolerance to the antihypertensive action develops early due to counterregulatory mechanisms
4. It primarily reduces systolic blood pressure with little effect on diastolic blood pressure
- c. Tolerance to the antihypertensive action develops early due to counterregulatory mechanisms