? Flashcards
Name prokinetic agents
Cholinergics: Neostigmine
Dopamine receptor antagonists: Domperidone
Serotonin receptor agonist: Metoclopramide
Macrolides: Erythromycin
Neostigmine
Mechanism
Use
Why is it not used so often anymore
reversible inhibition of acetylcholinesterase
perioperatively for acute colonic pseudo-obstruction or paralytic ileus
too diffuse a manner to be generally useful
Domperidone
Mechanism
FDA approved
Side effects
Mechanism
- Dopamine improves gastric motility (D2 receptor) and reduces lower esophageal and intragastric pressure by reducing acetylcholine release
- Domperidone inhibits the effects of dopamine in the myenteric plexus, but does not penetrate the BBB/CNS
FDA approved
- No?
Side effects
- Phenothiazines, are effective, but produce extrapyramidal side effects
Metoclopramide
Mechanism
Use
BBW
Mechanism
- 5-HT4 receptor agonist
- D2 receptor antagonism
Use
- 5-HT4: improves motility
- increased resting esophageal sphincter tone
- improved gastric tone and peristalsis
- relaxes pyloric sphincter
- augmented duodenal peristalsis
- no effect on gastric, pancreatic, or biliary secretion and only minimal contractual effect on the large intestine
SE
- extrapyramidal effects
BBW
- tardive dyskinesia ( in eldery esp. women
Erythromycin
Mechanism Use Which receptor SE Newest agent
Mechanism
Motilin agonist
Use
- Gastroparesis
Which receptor
- GPCR
- GI tract, expressed in smooth muscle cells from the antrum, duodenum and colon, and neurons of the myenteric plexus
SE
- utility of macrolide antibiotics is limited by tolerance and antibiotic effects (Bacterial resistance)
Newest agent
- Camicinal
Name antiematic agents
Dopamine receptor antagonists: Metoclopramide, Phenothiazine
Serotonin receptor antagonist: Ondansetron
Cannabinoids: Dronabinol
Histamine antagonists: Diphenhydramine
Metoclopramide, Phenothiazine
Class Mechanism Use High dose use? SE
Class
5-HT3 receptor antagonist
Mechanism
metoclopramide enhances gastric emptying, thus minimizing stasis which precedes vomiting
Use
acute or emergency situations, but have too many extrapyramidal side effects to warrant chronic use.
High dose
chemotherapy-induced nausea due to its prokinetic effects
SE
but high doses can result in extrapyramidal effects
Ondansetron
Class
5HT3R antagonist
Mechanism
- Peripheral & central action
- vagal afferents in the gut and in the area postrema
Use
- Chemotherap & radiation nausea
- Not eeffective in
Motion sickness
Efficacy
- Same as metocpromide but no CNS side effects
Dronabinol
Class
Use
SE
Class
cannabinoid
Use
chemotherapy-related nausea
Appetite stimulation
SE
high potential for abuse and adverse effects related to complex CNS actions
Diphenhydramine
Class
Use
Class
Antihistamine H1 antagonists
Use
motion sickness
Scoplomine
Vestibular disorders
Motion sikness
Name antacids
Mg, Al hydroxides
Mg, Al hydroxides
Mechanism
SE
Which is more effective (liquid or tablets)
Mechanism
Neutralize secreted acid; do not alter acid secretion
SE
Magnesium hydroxide has laxative properties (Mg = must go)
Aluminum hydroxide can cause constipation
Liquids more effective
Cimetidine
Class
SE
Class
H2-receptor antagonists
CYP450 inhibition
Omeprazole
Class Mechanism Use SE - Short term & long term
Class
Proton pump inhibitors
Mechanism
- Prodrug
- Covalent drugs
- Irreversible binding to proton pump
Use GERD (gastroesophageal reflux disease) Peptide ulcer disease Erosive esophagitis H. pylori eradication (“triple therapy” in combination with 2 antibiotics
SE Short Term mild and self-limiting - Pnnumonia - headache - Nausea - Abdominal pain - Flatulence and diarrhea
Long Term C. difficile infections Risk of fractures Acute interstitia nephritis Hypomagnesemia, Thrombocytopenia Fe deficiency Vitamin B12 deficiency Rhabdomyolysis
Diarrhea treatment
Metamucil
Loperamide
Metamucil
Mechani
Bulk forming agents (Metamucil (psyllium seed husks), etc.), whose mechanism of action is unknown
Loperamide
Opioids can act as antidiarrheal agents. Loperamide (Imodium and Imodium-AD) is 40-50 times more potent than morphine, as an antidiarrheal agent, and has a limited ability to enter the CNS. It is orally active, and very safe
IBS Treatment
Serotonin receptor modulators: Alosetron; Tegaserod
Alosetron
Class
Use
Mechanism
.Class
- 5-HT3 receptor antagonist
Use
- women severe diarrhea-predominant IBS (IBS-D)
- severe IBS-D who have failed to respond to conventional treatment for IBS
Mechanism
- Reduces motility and intestinal sensitivity to distension
SE
- , life-threatening, gastrointestinal side effects (ischemic colitis).
Tegaserod
Class
Use
Mechanism
.Class
5-HT4 agonist
Use
IBS-C, or chronic constipation
Mechanism
Relieves pain, bloating and constipation.
Can induce mild to severe diarrhea, which is dose-dependent.
There may also be increased risk of ischemic colitis
SE
heart attack, stroke, and unstable angina (compared to placebo)
IBD Treatment (4 agents)
5-Aminosalycilates: Sulfasalazine/Mesalamine
Glucocorticoids: Prednisone; Budesonide
Immunosuppressive agents: Azathioprine/6-mercaptopurine and Methotrexate
Biologicals: Infliximab
Sulfasalazine/Mesalamine
Use
- UC
Mechanism
- Pro drug ceave dby gut bacteria to Mesalamine (5-aminosalicylic acid, or 5-ASA)
- Give prodrug so that it can make it to large bowel else only effective in the small bowel
- Anti-inflamatory
SE
- Sulfa/salicalte agents
Prednisone; Budesonide
Use
Budesonide:
Kinetics
SE
Use
- Acute treatment is used to manage active disease and flareups
Budesonide
Kinetic: High first past in the liver
SE: Fewer
Azathioprine/6-mercaptopurine
Use
Which is pro durg
Limitations
SE
Use
- Immunosuppressive agents to treat moderate to severe IBD
- Maintain remission
Produrg- azithroprine
Limitations
take several weeks to produce effects in ulcerative colitis and Crohn’s disease. However, they reduce the requirement for steroids to maintain patients in remission
SE
bone marrow depression, leukopenia, teratogenesis
