antiemectic, gi motility, antacids Flashcards
Prompt neutralization of gastric acid. Not associated with acid rebound. Has laxative effect. Systemic absorption may be sufficient to cause neurologic, neuromuscular, and cv impairment in pts with renal dysfunction. Renal dysfunction can also lead to development of metabolic alkalosis in some pts.
Magnesium hydroxide (mom)
can produce metabolic alkalosis with chronic therapy. Symptomatic hypercalcemia may occur in pts with renal disease. May result in hypophosphatemia. Appendicitis has been reported due to impact calcium carbonate fecaliths
Calcium Carbonate
Mixture of aluminum hydroxide, aluminum oxide, and some fixed CO2 as carbonate. System absorption may be high in renal disease. Encephalopathy in pts undergoing hemodialysis has been attributed to intoxication with aluminum, especially in pts who ingest solutions containing citrate. Slows gastric emptying and causes Constipation)
Aluminum hydroxide
Less likely to cause foreign body reaction if aspirated and mixing with gastric fluid is more complete than with particulate antacids such as Tums or Rolaids (which can lead to pneumonitis and histological changes in lungs). 15-30 cc of a 0.3 mol/liter administered 30 minutes before induction of anesthesia is effective in reliably increasing gastric pH in pregnant and nonpregnant pts.
Non particulate antacids (Sodium Citrate):
Acid rebound is unique to _____________
calcium containing acids
Hypercalcemia, increased BUN and plasma creatinine concentrations. Have system alkalosis; marked decrease in renal function; Most commonly associated with ingestion of large amounts of calcium carbonate and > 1 L milk every day
Milk-Alkali Syndrome
Ingesting large doses of aluminum salts because they bind phosphate ions in the GI tract and prevent their absorption. May be beneficial in pts with renal disease because it can decrease their plasma phosphate concentration but renal pts may develop toxicity from the aluminum.
Phosphorus depletion
__________may result in anorexia, skeletal muscle weakness and malaise. Osteomalacia, osteoporosis, and fractures may occur. If aluminum containing antacids are given chronically should consider a phosphate supplement
Hypophosphatemia
H2 receptor antagonists competitively and selectively inhibit the binding of histamine to H2 receptors, thereby decreasing the intracellular concentration of cAMP and the subsequent secretion of hydrogen ions by parietal cells.
Cimetidine, ranitidine, famotidine, and nizatidine
________ least potent and __________ the most potent.
cimetidine, famotidine
Most effective at controlling gastric acidity and volume
PROTON PUMP INHIBITORS( PPI)
PROTON PUMP INHIBITORS( PPI)
Omeprazole, esomeprazole, Iansoprazole, pantoprazole, rabeprazole
PROTON PUMP INHIBITORS( PPI) MOA
Last phase of gastric acid secretion is the membrane enzyme proton pump (hydrogen-potassium-ATPase) that moves hydrogen ions across the gastric parietal cell membranes in exchange for potassium ions. The secretion of hydrochloric acid by gastric parietal cells depends on the function of the proton pump.
PPIs are more effective than H2-receptor antagonists for healing ________ and preventing relapse
esophagitis
Acts as a prodrug that becomes a PPI
OMEPRAZOLE
omeprazole takes _________to exert its maximal inhibitory effect on gastric acid secretion.
several days
Heals duodenal and possible gastric ulcers more rapidly than H2 receptor antagonists
OMEPRAZOLE
In pts with bleeding PUD and signs of recent bleeding, treatment with ________ decreases the rate of bleeding and the need for surgery
omeprazole
Administered the night before surgery, increases gastric fluid pH, whereas administration on day of surgery (up to 3 hours before) fails to improve the environment of gastric fluid
omeprazole
Omerprazole side effects
Crosses BBB and may cause: headache, agitation and confusion
GI: abd pain, flatulence, n/v
No need to adjust dose in renal or hepatic dysfunction
Increase lower esophageal sphincter tone, enhances intraduodenal coordination and promotes gastric emptying of liquids and solids in pts with diabetic gastroparesis; patients awaiting emergent surgery; normal pts; ICU pts with food intolerance
MACROLIDES: Erythromycin, Azithromycin
Decreases GERD; Increases lower esophageal sphincter tone; improves gastric motility and increases motility in small and large intestine by enhancing the release of acetylcholine from nerve endings in the myenteric plexus of the gastrointestinal mucosa.
5-HT4-RECEPTOR AGONISTS:
Cisapride and Mosapride
Opioid induced gastric stasis (can cause post op n/v) is reversed by _________
cisapride
Due to nonselectivity, ______ and _______ are associated with prolongation of QT interval.
cisapride and mosapride
PONV RISK FACTORS PEDIATRICS
Age: Weak Association Herniorrhaphy T&A Strabismus Surgery Male Genitalia Surgeries: Highest Risk Risk reduced in adults as they age
PONV RISK FACTORS ANESTHETICS
Inhalation Agents Nitrous Oxide Neostigmine Opioids Correlation is limited with these factors and PONV
PONV RISK FACTORS Surgical Factors
Length of Surgery Laparotomies Gynecologic surgeries Laparoscopic procedures ENT Breast Plastic Ortho
CENTRAL ANTICHOLINERGIC SYNDROME treatent
Physostigmine (lipid-soluble tertiary amine) 15-60 mcg/kg IV is a specific treatment. Treatment may need to be repeated every 1-2 hours.
Atropine 0.6 mg IV or Glycopyrrolate 0.2 – 0.3 mg IV decreases ____________________ and decreases barrier pressure
lower esophageal sphincter pressure
The difference between ______ and _____ sphincter pressure is “barrier pressure.”
gastric pressure, lower esophageal
stimulates GI tract via cholinergic mechanism resulting in:
Contraction of lower esophageal sphincter and gastric fundus
Increased gastric and small intestinal motility
Decreased muscle activity in the pylorus and duodenum when stomach contracts
Benzamides: Metoclopramide and Domperidone
Because of antidopaminergic activity, Reglan should be used with caution if at all in:
Parkinson’s disease
RLS
Pts with movement disorders related to dopamine inhibition or depletion.
Can give _______ prior to Reglan to prevent side effects
versed
reglan Potential gastric emptying benefits:
Patients who have recently ingested solid food
Patients with DM and symptoms of gastroparesis
Trauma patients
Obese
Parturients (especially with esophagitis/heartburn suggesting LES dysfunction and gastric hypomotility
Reglan Should not be administered to patients with:
Known Parkinson’s Disease
Restless Leg Syndrome
Movement disorders r/t dopamine inhibition or depletion
Reglan May increase sedative actions of CNS depressants and the incidence of extrapyramidal reactions cause by certain drugs: Should avoid administering in combination with:
Phenothiazine
Butyrophenone drugs
Patients with preexisting extrapyramidal symptoms
Seizure disorders
Avoid in patients taking MOAI or Tricyclic antidepressants
Decreases bioavailability of orally administered cimetidine by 25-50%
Do not give to suspected or known mechanical obstruction to gastric emptying
Do not administer after GI surgery such as pyloroplasty or intestinal anastomosis because it stimulates gastric motility and may delay healing
Inhibiting effect on plasma cholinesterase activity: May cause prolonged responses to succinylcholine and mivacurium: Parturients may be at increased risk for developing this response, considering the already decreased plasma cholinesterase activity associated with pregnancy.
Metabolism of ester LA could be slowed by reglan induced decreases in plasma cholinesterase activity
