Pharmacologic Treatment of Motility Flashcards
Cardinal sign of achalasia
birds beak (+/- sigmoid esophagus)
2 approaches to treating esophageal motility disorders
- lower LES pressure, 2. reduce vigor of distal contractions
Tx for achalasia
- botulinum –> inhibits ACh release
2. heller myotomy, POEM
Tx for esophageal hypercontractile state
PDE5I –> block no degradaition, prolong smooth muscle relaxation, reduce contractile amplitude and propagation velocity
Tx of gastroparesis
pyloroplasty
Which cells in the stomach create their own electrical activity?
interstitial cells of cajal –> slow wave activity –> modulated by vagus and enteric nerves
2 important receptors in excitatory enteric cholinergic motor neurons
5HT3 and 5HT4
3 important receptors in inhibitory enteric nitrergic motor neurons
5HT7, 5HT1A, 5HT1D
Where is the majority of serotonin in body?
gut (95%)
MOA Metoclopramide
serotonin 5HT4 agonist (promotes muscle conraction), D2 antagonist (dopamine inhibits muscle contraction) –> diabetic gastroparesis, antiemetic
3 ways to delay gastric emptying
anticholinergic: dicylomine, hyoscyamine
somatostatin analog: octreotide (inhibit serotonin and motilin)
Tx of poor accomodation
busiprone: 5HT1A receptor agonist–> increase NO release, inhibits ACh release –> tx of functional dyspepsia, improves accomodation
Tx of constipation
water, fiber (only for mild/moderate), laxatives
- mg, sulfate, phosphate hyperosmolar intraluminal envronment
- PEG: isoosmotic, binds water molecules
- Anthraquinone/diphenylmethanes: afferent nerve fiber irritants
- lubiprostone
- tegaserod
Lubiprostone MOA
increase intestinal fluid secretion by activating CFTR
Tegaserod MOA
5HT4 partial agonist –> improves constiption
Dangers of tap water and soap suds enemas for constipation.
water: intoxication
soap: colitis/necrosis
How do blood borne and local emetics cause emesis?
5HT3 release in stomach/small intestine –> vagus nerve afferent –> chemoreceptor trigger zone –> emetic center in medulla
Types of anti-emetics
5HT3 antagonists (ondansetron), central dopamine antagonists, H1 antagonists, muscarinic antagonists, neurokinin antagonists, cannabinoid AGonists
