aahy1978
Forum Junior
Topics: 11
Posts: 39
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Why does Clonidine casue "dry-mouth" ??
Clonidine is an Alpha-2 Agonist, which inhibits release of Norepinephrine... so, basically it decreases sympathetic activity right?
anyway, if salivation is a characteristic of parasympathetic activity since it increases glandular secretions...
and atropine (a muscuranic receptor antagonist--para blocker) also causes dry mouth...
i dont get it... am i missing something or this one of those side effects i just have to accept as is and memorize without any understanding as why that is cry cry
in anycase, i'd really appreciate if anyone shed some light on this.... thanx for reading D
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| mjl1717
Forum Hero
Topics: 958
Posts: 5,465
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Clonidine-dual mech. of action:
1)alpha2 agonist centrally(as you say inhibiting NE)
2)alpha2 agonist peripherally(inhibiting NE)
Salivary glands-dual inervation
1)Parasympathetic for the watery secretions
2)Sympathetic for the viscous secretions via (alpha 2 and beta2)
Xerostomia-It is possibly due to a central mechanism and stimulation by clonidine of alpha 2 adrenergic receptors found on cholinergic fibers innervating salivary glands.
Most important for clonidine is the MAO, side effects, and "unique specifics"
similar to methydopa and guanabenz, "rebound", pre-rxed with phentolamine, inhibits renin, can potentiate insulin induced hypoglycemia,
may act weirdly with tricyclics.
*I doubt if usmle would "dig you" about any 1 side effect/ more important to know if there is a side effect and what side effect it is!
Hope this helps.
___________________
Smell the coffee! "Is That an Osler move??"
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| aahy1978
Forum Junior
Topics: 11
Posts: 39
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thanx mjl1717
i guess ur right... dont need to concern myself with little details like that... its better to look at the bigger picture...
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