Pharm Exam 2 Flashcards
What are 6 muscarinic agonists?
acetylcholine, methacholine, carbachol, Bethanechol, muscarine, pilocarpine
What happens to Ach with the use of anticholinesterases?
Ach concentrations increase; these prevent the breakdown of Ach into choline and acetate
What are some reversible anticholinesterases?
edrophonium, neostigmine, pyridostigmine, rivastigmine, donepezil, galantamine
What are some irreversible anticholinesterases?
insecticides- malathion, diazinon, chlorpyrifos
nerve gases- sarin, tabun, soman
What are some therapeutic uses for anticholinesterases?
atonic bladder and GI tract, glaucoma, reversal of neuromuscular blockade, myasthenia gravis, Alzheimer’s disease
What is the preferred agent for paralytic ileus and atony of the urinary bladder?
neostigmine; peristalsis is fast when given subcutaneously
What is the mechanism of action of anticholinesterase when treating glaucoma?
there is contraction of ciliary muscle which allows aqueous humor to flow out -> decreasing intraocular pressure
Why is echothiophate not typically used in glaucoma?
it has been associated with the development of cataracts
What is myasthenia gravis?
autoimmune neuromuscular disorder characterized by significant skeletal muscle weakness; appears to result in decrease in ACh receptors
What is the tensilon test?
uses the drug tensilon to diagnose myasthenia gravis; tensilon is an anticholinesterase which helps prevent the break down of ACh which in turn helps stimulate the muscles; a patient has myasthenia gravis if muscles get stronger after being injected with Tensilon
What is the treatment for myasthenia gravis?
Physostigmine q2-4h; Neostigmine q3-6h; Ambenonium q3-8h
What is the pathophysiology behind Alzheimer’s Disease?
patients demonstrate a loss of neurons particularly cholinergic types
What is typically used to treat Alzheimer’s Disease?
donepezil, rivastigmine, galantamine; side effects include nausea, vomiting, diarrhea
What will be apparent in contact with organophosphates?
SLUDGE
How can one treat organophosphate poisoning?
administer atropine and pralidoxime STAT; remove all contaminated clothing immediately; wash skin with soap and water; rinse eyes with plain water for 10-15 min; maintain airway; do not induce vomitting
Where does acid production occur?
parietal cells
what receptors are on parietal cells?
gastrin, acetylcholine, histamine
Where does acetylcholine come from?
vagal stimulation of postganglionic enteric neurons
Where does gastrin come from?
G cells
Where does histamine come from?
ECL cells
What is a negative effect of antacids?
can impair absorption of iron and some antibiotics; decreases stomach acidity can impair the body’s ability to absorb protein, carbs, fats, vitamins A.E.C, folate, micro-trace elements, and minerals
What H2-receptor antagonist is not available IV?
nizatidine
What H2-receptor antagonist is most potent and most selective?
famotidine- with a duration of action of 10-12h
What excretes H2-Receptor Antagonists and why is this important?
the kidneys- must reduce the doses in people that have impaired renal functions