Agents for Gastrointestinal DIsorders Flashcards
Antacid best taken at night
H2 receptor antagonist
Antacid best taken in the morning
Proton pump inhibitor
Causes of peptic ulcer disease
NSAIDs and H. pylori
Receptors facilitating HK-ATPase
M3 (Muscarinic), CCK2 (Gastrin), and H2 (Histamine)
Prostaglandin analog to save and protect the mucosa
Misoprostol
Protects mucosa from acids
Sucralfate
Basal rate of acid secretion
1-5 microEq
Fast acting antacids
Sodium bicarbonate and Calcium bicarbonate
Adverse effect of Aluminum hydroxide
Constipation
Adverse effect of Magnesium hydroxide
Osmotic diarrhea
Effects of antacids
Increased LES pressure and gastric emptying time, pepsin inactivation, and mucosal protection
Duration of action of antacids in a fasting state
30 mins (due to gastric emptying)
Duration of action of antacids with meals
2 to 3 hours
Minimum neutralizing capacity of antacid
5 mEq/dose
pH level at which ulcers start to heal
3.5
Adverse effects of Calcium bicarbonate and Sodium bicarbonate
Belching
Antacids should be taken 2 hours before or after ingestion of:
Tetracycline
Fluoroquinolone
Itraconazole
Iron preparation
Most potent H2 receptor antagonist
Famotidine
Least potent H2 receptor antagonist
Cimetidine
Modified histamine molecule with an imidazole ring
Cimetidine
Modified histamine molecule with a furan ring
Ranitidine
Modified histamine molecule with a thiazole ring
Famotidine
MOA of H2RA
Inhibitors of histamine at H2 receptor; decrease gastrin and pepsin secretion
Clinical uses of H2RA
GERD
PUD
NUD
Stress related gastritis
Adverse effect of Cimetidine
Inhibits estradiol metabolism causing hyperprolactinemia
H2RA increases bioavailability of ethanol EXCEPT
Famotidine
PPI with the shortest half-life
Omeprazole
PPI that is the fastest activated at pH 1.2
Rabeprazole
Most potent suppressor of gastric acid secretion
Proton Pump inhibitors
Drugs that inhibit both fasting and meal stimulated secretion
H2RA and PPI
Healing time of duodenal ulcers
4 weeks
Healing time of gastric ulcers
6 to 8 weeks
PPI Therapy for actively bleeding ulcers
80mg initial IV bolus then 80mg constant infusion at 8mg/hr
PPI is given with what drugs when used as treatment for H. pylori associated ulcers?
Amoxicillin and Clarithromycin
PPIs affect the absorption of:
Vit B12, Iron, Calcium, and Zinc
PPI, PG, H2RA, and Antacids are used to:
heal the ulcer, pain relief, and prevent complications
Regimen to reduce recurrence of ulcer:
HP eradication, PPI, and H2RA
This drug group reduces clopidogrel activity
Proton Pump Inhibitors
MOA of Sucralfate
Binds to necrotic ulcer tissue and serves as barrier to acid, pepsin, and bile for up to 6 hours
Colloidal bismuth compounds combined with which antibiotics will enhance ulcer healing up to 98%
Metronidazole and Tetracycline
Increases prostaglandin secretion and scavenges reactive oxygen species
Rebamipide
Reduces incidence of NSAID induced ulcers and stimulates uterine contraction
Prostaglandin analogs
Agents (regimen) used to eradicate H. pylori
PPI (usual ulcer dose)
Amoxicillin
Clarithromycin
Cholinomimetic agent used for GERD that stimulates M3 receptors
Bethanechol
Acetylcholinesterase inhibitor used for acute colonic pseudo obstruction or Ogilvie’s syndrome
Neostigmine
Drug of choice for GERD
Proton Pump Inhibitors
MOA of Dopamine receptor antagonist
Blocks inhibitory effect of dopamine and blocks D2 receptors
Dopamine receptor antagonist that promotes postpartum lactation
Domperidone
Produce extrapyramidal symptoms of dystonia, akisthisia and Parkinsonian features
Metoclopramide, Trimethobenzamide
MOA of macrolides
Stimulates motilin receptors and promote migrating motor complex
MOA of Serotonin 5-HT4 receptor agonist
Stimulates second order enteric neurons to promote peristaltic reflex
Neurotransmitters promoting proximal bowel contraction
AcH and Substance P
Neurotransmitters promoting distal bowel relaxation
NO and VIP
Serotonin 5-HT4 receptor antagonist with QT prolongation effects
Tegaserod
Complex plant polysaccharide or cellulose derivatives that swell on contact with water to distend colon and promote peristalsis
Bulk forming agents
Luminally active agents
Bulk-forming agents
Osmotic laxatives
Stool softeners
Increases stool liquidity due to an obligate increase in fecal fluid
Osmotic laxatives
Examples of osmotic laxatives
Milk of Magnesia
Sorbitol and Lactulose
Mg citrate and Na phosphate
Polyethylene glycol (PEG)
Laxative for preparation in GI endoscopic procedures
Polyethylene glycol
Clinical uses of osmotic laxatives
Treat acute constipation and prevent chronic constipation
Adverse effect of bulk forming agents
Bloating and Flatus
Adverse effect of osmotic laxatives
IV volume depletion and electrolyte imbalance
Stool softeners
Docusate
Glycerin suppository
Mineral oil
Adverse effects of stool softeners
Impair absorption of fat soluble vitamins (ADEK)
MOA of stool softeners
decrease colonic absorption of water allowing easier stool passage
Stimulants or Irritants
Cathartics and Chloride channel activator
MOA of stimulant laxatives
Direct stimulation of ENS, colonic electrolyte and fluid secretion
Laxative promoting melanosis coli
Antraquinone derivatives (aloe, senna, cascara)
Stimulant laxative safe for acute and long term colonic atony use
Bisacodyl
Potent stimulant laxative promoting intestinal motility
Castor Oil
Adverse effect of cathartics
Colonic atony and dilation
Stimulates type 2 chloride channel in small intestine and causes constipation recurrence on discontinuation
Lubiprostone
MOA of opioid antagonist
Inhibits peripheral mu opioid receptors
Treatment of opioid induced consipation in patients receiving palliative care
Methylnaltrexone
Short term use in post-operative ileus after small and large bowel resection
Alvimopan
Osmolarity of replacement therapy
200-320 mmol/L
Non-prescription anti-diarrheal opioid agent with no analgesic property
Loperamide (Diatabs)
Anti-diarrheal opioid agent that contains small amount of atropine that can cause CNS toxicity in higher doses
Diphenoxylate (Lomotil)
Bile salt binding protein resins
Cholestyramine and Colestipol
Reduces intestinal fluid secretion and contracts vascular smooth muscle leading to reduction of portal and splanchnic blood flow
Somatostatin
Synthetic octapeptide with similar action to somatostatin given SC or IV only
Octreotide
MOA of Serotonin 5-HT3 receptor antagonists
Inhibit colonic motility, increasing transit time
Inhibit afferent GI 5-HT3 receptors to decrease visceral pain
Drug that is a Serotonin 5-HT3 receptor antagonist
Alosetron
Drug that is a Serotonin 5-HT4 receptor antagonist
Tegaserod
Drugs used for emesis secondary to vagal stimulation
5-HT3 antagonists (-setron) Ondansetron
Adverse effects of Dolansetron
Prolonged QT interval
Enhances efficacy of 5-HT3 receptor antagonists for prevention of vomiting
Corticosteroids (Dexamethasone and Methylprednisolone)
Antipsychotic agent with potent antiemetic and sedative properties
Phenothiazines and Butyrophenones
Weak antiemetic activity as single agents and prevents motion sickness
H1 antihistamines and anticholinergics
Muscarinic receptor antagonist that is the best agent to prevent motion sickness
Hyoscine (Scopolamine)
Less sedation used for motion sickness and treatment of vertigo
Meclizine
Sedative used in conjuction with other antiemetics in patients undergoing chemotherapy
Diphenhydramine
Cannabinoid reecptor agonist that is a major psychoactive chemical in marijuana used as appetite stimulant and antiemetics
Dronabinol (THC)
THC analog
Nabilone
First line treatment for mild to moderate ulcerative colitis
5-aminosalicylic acid
Purine analogs used in induction and maintenance of remission of ulcerative colitis and Crohn’s disease
Azathiorpine and 6-mercaptopurine
Immunosuppressive agent that inhibits dihydrofolate reductase and interferes with IL-1 action
Methotrexate
Drugs used for acute and chronic treatment of ulcerative colitis and Crohn’s disease with inadequate response to conventional therapies
Anti-tumor necrosis factor therapy:
Infliximab (-umab)
MOA of anti-integrin therapy (Natalizumab)
Prevents binding of inflammatory cells to integrin and vascular adhesion molecules
Bile acid therapy for gallstones
Ursodiol
Inhibits glucagon release and used as treatment for bleeding esophageal varices
Somatostatin and Octreotide
Causes splanchnic arterial vasoconstriction to regulate upper GI bleeding
Vasopressin and Terlipressin
Prophylaxis for variceal bleeding
Beta-receptor blockers
Used in non-variceal bleeding
Proton pump inhibitor
Used enteral for burn and trauma patients
Glutamine
Immuno nutrition considered for critically ill patients
Selenium (antioxidants)
Enteral formula for acute respiratory distress syndrome
Fish oils