Pharmacology

Question 0

Parasympathetic hypersensitivity

Answer 0

excessive parasympathetic activity (excessive acetylcholine): excessive sweating, urination, and bradycardia.

Ex: pesticide poisoning; classic insecticide is parathion which is an indirect acetylcholinesterase inhibitor.

Mnemonic that can be used to remember the signs of parasympathetic hyperactivity is 
DUMBELLS: 
Diarrhea, 
Urination, 
Miosis, 
Bradycardia, Bronchoconstriction, 
Emesis, 
Lacrimation, 
Salivation, Sweating, Secretion.

Question 1

Apraclonidine

Answer 1

Apraclonidine: The second ‘a’ in the word is followed by ‘c’ – ergo, alpha 2 constricts. AND the first ‘i’ is followed by ‘d’ – ergo, alpha I Dilates.

All you have to remember is that Alpha-1 receptors are upregulated (think more abundant) in the Horners pupil.

Apraclonidine is an alpha-adrenergic receptor agonist that has more effect on alpha-2 receptors than alpha-1 receptors. It is not completely clear how it functions in the diagnosis of Horner syndrome, but the current theory revolves around up-regulation of post-synaptic alpha-1 receptors in Horner syndrome.

The belief is that as early as 36 hours following disruption of sympathetic fibers to the eye, the pupillary dilator muscle experiences up-regulation of alpha-1 receptors in response to sympathetic denervation. A normal pupillary response to apraclonidine 0.5% (trade name Iopidine) is mild constriction due to action of the medication on pre-synaptic alpha-2 receptors which act to decrease release of norepinephrine to the dilator muscle. In patients with Horner syndrome, however, the action of apraclonidine on up-regulated alpha-1 receptors predominates over the alpha-2 effect resulting in dilation.

In an individual with unilateral Horner syndrome who has apraclonidine drops applied bilaterally, the sympathetically denervated eye dilates and the normal eye constricts leading to reversal of anisocoria.

Question 2

Miostat vs. Miochol

Answer 2

Miostat STAYS..therefore it is hard to break down and must be carbachol (lasts 24 hrs) and then Miochol must be Acetylcholine, more easily broken down by acetylcholinesterase.

both cause contraction of longitudinal ciliary muscle and lower IOP

Question 3

Alpha agonists

Answer 3

(“ALGAN”)
Allergy / anaphylaxis
Lid retraction
Groggy (bradycardia)
Apnea
Nutty (CNS depression in kids)

Question 4

Bacteriostatic Drugs?

Answer 4

STatiC (Sulfa, Tetra, Clinda/Chloram)