Pharm Flashcards
What are the sympathetic receptors in the GI responsible for relaxation of walls and contraction of Sphincters?
alpha 2 and Beta 2–> relax
Alpha 1–> contract
PSNS–> ALL m3 receptors
What are AE of muscarinic Agonists or AchE inhibitors?
Diarrhea Urination Miosis Bronchorrhea Bradycardia Emesis Lacrimation Salivation/ Sweating **DUMBBELS
Which GI Neurotransmitter is the primarily excitatory transmitter of smooth muscle and glands. Major neuron-neuron (Ganglionic) transmitter in the ENS?
ACh
GI neurotransmitter that is Modulatory in the ENS?
Dopamine (inhibits ACh release)
GI substance that inhibits ACh release and peristalsis. May stimulate secretions?
Enkephalins (OPIOID peptides)
GI substance that inhibits secretion of water and electrolytes by the gut. Causes long lasting vasoconstriction?
NPY
GI substance that in inhibitory at ENS, especially @ Sphincters?
NO -> think Achalasia
What are some of the implicated causes of IBS?
Abnormal GI motor function (hypersen, autonomic dysfunction) Serotonin disequilibrium (Diarrhea form-excess, C-Lack)
What is the difference between SNS and PSNS stimulated salivary secretions?
PSNS= Copious but protein POOR SNS= Sparse But Protein RICH
Describe the pathway leading to salivary secretion by ACh stimulation?
ACh-> M3 (g-protein)-> IP3-> Ca+-> Increased Cl- discharge + H2O follows
What is the MOA of Cevimeline?
M3»M1 Agonist used to increase Salivary Flow
What is the MOA of Pilocarpine?
Muscarinic receptor Agonist== Increases Salivary flow
What are the AE of Cevimeline?
CI: Asthma, Glaucoma, iritis
Caution: COPD, driving (vision loss), MI, pregnancy, and nephrolythiasis
What are the AE of Pilocarpine?
CI: asthma, Glaucoma, iritis
Caution: Psychosis, CNS, MI, COPD, vision loss
Free radical scavenger that is protects the salivary glands during Head and neck radiation?
Amifostine–> Also protects from CISPLATIN nephrotoxicity
Caused by altered mucosal resistance and associated with reduced gastric acid output?
Gastric ulcer
Associated with High gastric output, and inadequate bicarbonate secretion and insufficient acid neutralization?
Duodenal ulcer
What is the goal of antacid?
Neutralize the gastric acid:
- 3-1.6= 50% neutralized
- 3-2.4= 90%
* **pH > 4 == prevent Activation of Pepsin
What ingredient in antacid causes diarrhea? Constipation?
Diarrhea= Aluminum Hydroxide Constipation= Magnesium
What is simethicon?
Surfactant
What is Mg+/ Al used for?
Antacids
MOA of calcium carbonate?
TUMS –> Antacid that is FAST ACTING
What are AE of antacids?
Affects absorption of other Drugs (avoid within 1-2hrs of taking other drugs)
Take 1-3 hrs after meals or @ bedtime
WHat is the MOA of Cimetidine, Famotidine, or any Tidines?
H2 receptor blockers
What is the affect of Cimetidine or any other H2 blocker?
Inhibit basal, food stimulated, and nocturnal Gastric acid secretion
**reduce BOTH volume and concentration
Which H2 blocker inhibits the activity of CYPs and thus slows down the metabolism of other drugs?
Cimetidine
MOA of Omeprazole, Pantoprazole, Lansoprazole?
PPI–> Inhibit the H+/K+ ATPase= Inhibit HCL secretion
What drugs are enterically coated so the Pro-drug is released in the intestines, absorbed in the blood stream. and carried to parietal cells where it has its affects?
PPI
**Low pH near the parietal cells Protonate the drugs and TRAP them near the Proton pumps
What is the MOA of protonated omeprazole, or other azoles?
Permits IRREVERSIBLE binding to H/K ATPase
**Results in Achlorhydria
What is the only way to reverse the affects of Omeprazole and other PPIs?
In order to return to normal acid secretion, Parietal cells must synthesize NEW H/K ATPase
Which PPI not a major substrate for CYP metabolism?
Rabeprazole-> Lower extent metabolism by CYPs
MOA for Bismuth subsalicylate?
Pepo Bismol --> 1 Enhances secretion of mucus and HCO3 2 Inhibits pepsin activity 3. Chelates with proteins at ulcer and forms protective barrier against acid and pepsin 4. Inhibits H pylori 5. effective against Travelers diarrhea
What drug is affective against both Travelers diarrhea and H pylori?
Bismuth (Pepo bismol)
MOA for Sucralfate?
Forms sticky, viscous gel –> protects gastric epithelial cells from acid and pepsin
What is the only cytoprotective agent that requires an ACID pH for maximal activity?
Sucralfate
What gastric protective agent is used in bedridden patients and why?
H2 or PPI induced pneumonia= Alkalinizing the stomach for protection would cause Pathogenic bacterial growth == Give SUCRALFATE which works in acid conditions and protects stomach
MOA for Misoprostol?
PGE1 analog
***Stimulates Mucus and HCO3 production
What are the AE of Misoprostol?
Intolerable DIARRHEA
When would Misoprostol be used?
Chronic NSAID users–> protect gastric mucosa from NSAID induced ulcers
What is the treatment for H pylori induced PUD?
H2 blocker
Bismuth
1-2 antibiotics
Which of the antibiotics used to treat H pylori have the highest resistance rate?
Metronidazole (40%)
Tetracycline (<1%)
What are the postural and dietary therapies for GERD?
Smaller meals Weight loss Elevate Bed Low Fat diet Avoid coffee or peppermint (relax LES)
MOA for metoclopramide?
Prokinetic drug–> Dopamine receptor blockers (D2) increasing local release of ACh via 5HT4-R agonism== Enhances Gastric emptying
**D2R blocker + 5-HT4R Agonist
Drugs that stimulate GI smooth muscle, increase amplitude of esophageal contractions, Accelerates gastric emptying, and Increases LES pressure?
Meochlopramide + Domperidone
**D2 receptor blockers
What is the MAIN anti-reflux mechanism of Metochlopramide?
Enhanced Gastric motility
What are the AE of Metochlopramide?
Tardive dyskinesia
Parkinson’s like movements
What drug Enhances ACh release by acting on 5-HT4R?
Metochlopramide (also blocks D2R)
What is the MOA for Domperidone?
D2R blocker
What is the MOA for Sulfasalazine?
5-ASA = local anti-inflammatory agent
**Used in IBD
What are the AE for Sulfasalazine?
Anemia
Rash
Impotence
MOA for Inflizimab?
mab that inhibits/binds TNF alpha
**Given IV to Crohns disease patients
MOA for lactulose?
semisynthetic disaccharides + metabolized by enteric bacteria + Acidifies Feces –> traps and eliminates NH3
MOA of Increased fiber intake treatment for constipation?
Increases H2O delivery to colon
Increases Bulk
Decreases pressure in sigmoid colon
**More formed stool (also for diarrhea)
What is MOA for Effer-syllium/ Metamucil?
Metamucil–> Hydrophilic muciloid that forms gelatinous mass when mixed with water
AE of Effer syllium?
Allergic rxn Flatulance Intestinal obstruction Borborygmi (stomach rumbles) INHIBIT coumarin absorption
Hydrophilic muciliod producing substance used to relieve constipation?
Syllium / Metamucil
MOA of Mitrolan?
Hydrophilic resin that absorbs 60-100x water in weight
AE of Mitrolan?
Release Calcium–> CI with tetracylcine use