Antihistamines and GI Drugs Flashcards
Diphenhydramine
Mechanism: Histamine H1 Receptor Antagonist. Ethanolamine class.
Usage: Allergic rxns (pruritis, urticaria, rhinorhea etc), insomnia, motion sickness.
Toxicity: Sedation, anti-cholinergic effects (dry mouth, flushing, urinary retention, nauseau, tachycardia)
Hydroxyzine
Mechanism: Histamine H1 Receptor Antagonist. Piperazidine class
Usage: Anti Allergenic, anxiety, anti-emetic
Toxicity: Sedation, dizziness, hypotension, tinnitus & anti-cholinergic effects (GI effects)
Other: Contraindicated in pregnancy
Brompheniramine
Mechanism: Histamine H1 Receptor Antagonist. Alkylamine class (Dimetapp)
Usage: Daytime allergy med, cold symptoms
Toxicity: mild sedation and anti-cholinergic effects.
Other:
Loratidine
Mechanism: Histamine H1 Receptor antagonist. 2nd generation
Usage: Allergy
Toxicity: minimal anti-cholinergic effects
Other: 2nd gen- doesn’t cross CNS due to zwitterionic state.
Rantidine (Zantac)
Mechanism: Histamine H2 receptor antagonists. Histamine analog
Usage: GERD, Heartburn, gastric/peptic ulcer
Toxicity: Minimal
Other: can compete w/ CYP metab and renal tubular excretion of other drugs some. Not as effective as PPI’s
Omeprazole
Mechanism: Proton Pump Inhibitor: irreversible inhibitors of H+/K+ ATPase in parietal cells.
Usage: GERD, hearburn, gastric/peptic ulcers
Toxicity: Impact absorption of drugs that are dependent on low stomach pH
Other:
Sucralfate
Mechanism: Sucrose aluminum salt- reacts w/ HCl to form protective barrier in stomach
Usage: Gastric/Peptide ulcers, permits repair of lining.
Toxicity: Constipation, flatulence
Other: taken q4d
Misoprostol
Mechanism: Prostaglandin receptor agonist (increase mucosal secretions, inhibits proton pumping)
Usage: 1st Line: NSAID ulcers. Gastric/Peptic ulcer (Not first line).
Toxicity: Diarrhea, abdominal pain (minor)
Other: Used topically to induce contractions in labor and in conjunction w/ mifepristine for abortion- check to see if pregnant to avoid unintentional abortion…
Bismuth Subsalicylate (Pepto Bismol)
Mechanisms: GI/Mucosal protective agent
Usage: Dyspepsia, diarrhea
Toxicity: Black stools, reye’s syndrome (?)
Other: 1st generation anti-histamine.
Metoclopramide
Mechanism: 5-HT4 receptor agonist, D2 dopamine receptor antagonist
Usage: prokinetic for gastric emtying, GERD, gastritis, dyspepsia, anti-emetic
Toxicity: estrapyramidal effects, hyperprolactinemia w/ chronic use
Other:
