HY 24

[Anonymous]

Your patient is a hypertensive asthmatic. What drug can you give him? Prazosin, Propranolo, Reserpine or Clonidine

[Anonymous]

i think this question meant to ask which one is contraindicated in asthmatics coz i only know of propranolol being contraindicated in asthmatics. propranolol is a non-selective beta blocker (beta 1 and 2) which means that its beta 2 blocking activity can cause bronchoconstriction. the others listed are alpha blockers, so i can't really see how they differ much from each other in relation to asthmatics? but if someone knows, please share.


Ref: kaplan pharm notes pg 99-100

[stergs]

I agree with Step 1 on this. Its trying to make sure that you know that propanolol shouldn't be given for cardiac purposes to an asthmatic.

[Anonymous]

I agree with you both...

[Anonymous]

My approach is comparing the three drugs on their mechanism, properties and selectivities:
I. Reserpine interfers with Norepinephrine which has alpha 1,2 and beta 1 activity, thatmeans it is safe for asthmatic patient; also it has sedative property.
II. Clonidine(alpha agonist-can have severe Rebound Hypertension), and we have Prazosin(alpha antagonist). So Clonidine will not be the answer.
III. Between Prazosin and Reserpine, I will choose Reserpine.
IV. Final answer: C.

[Anonymous]

[usifoosemota]

The question is asking for what you could give him for his hypertension, that would not interfere with his asthma. Propranolol blocks beta 2 receptors and would hence cause bronchospasm. reserpine would reduce the amount of catecholamines in the synaptic cleft, which would have the same effect on brochioles as propranolol. Prazosin is an alpha 1 blocker and cuses only smooth muscle relaxation. Hence it is a good choice for an asthmatic but not the best from this list as it is a peripheral vasodilator and can cause reflex tachycardia. You bet this tachycardia is gonna add up to the one they get from albuterol admisistration; this can be perceived as palpitations and can even mimick a panic attack. Clonidine on the other hand is a central alpha 2 blocker that has no effect on bronchiole smooth muscle. Does not cause reflex tachycardia. However, abrupt discontiuation can cause rebound hypertension. From this list, clonidine will be the best option to treat hypertension in an asthmatic.

[RussianJoo]

I don't think this person cares anymore what the answer is because he wrote the question in 2003 about 5 years ago.. And also, as stated previously he miss typed the question and meant to ask what's contraindicated in an asthmatic. which is propranolol.