Amboss ANTIEMETIC Flashcards
antiemetic groups?
Dopamine receptor antagonists;
Serotonin receptor antagonists
(5-HT3 antagonists);
Anticholinergic agents;
Antihistamines
Neurokinin receptor antagonists
Dopamine receptor antagonists?3
Prochlorperazine, METOCLOPRAMIDE, Domperidone
Metoclopramide. mechanism?
D2 receptor antagonist.
metoclopramide. Where action in brains?
Central antiemetic effect at the area postrema.
Metoclopramide. Peripheral GI effect?
Peripheral antiemetic effect in the gastrointestinal tract (prokinetic effect);
Metoclopramide. What prokinetic effect?
incr. Gastric contractions (contractility)
incr. Duodenal and jejunal motility
incr. Resting tone of the lower esophageal sphincter
incr. LES tone
promotes gastric emptying
Metoclopramide. effect on colon?
Does not influence colon transport time (no effect on colon motility)
Metoclopramide. Together with decreased pylorus sphincter activity allows food to pass more quickly through the stomach and the small intestine
.
Indications of metoclopramide?
Diabetic and postoperative gastroparesis, antiemetics, persistent GERD.
Hyperemesis gravidarum
why metoclopramide for postsurgery gastroparesis?
due to prokinetic effect on stomach
metoclopramide. GI adverse?
diarrhea, pain
metoclopramide. neuro adverse?
Depression, anxiety Fatigue Drowsiness Restlessness !!!Lowering of seizure threshold
Overdose leads to reversible extrapyramidal syndrome (e.g., dystonia, parkinsonism, !!tardive dyskinesia, and akathisia).
Do not combine metoclopramide with antipsychotics because this increases the risk of dyskinesia!
Antidote: biperiden (anticholinergic agent)
metoclopramide + antipsychotics?
Do not combine metoclopramide with antipsychotics because this increases the risk of dyskinesia!
metoclopramide antidote for neuro adverse?
Antidote: biperiden (anticholinergic agent)
metoclopramide has important interacton with what 2 medications?
digoxin and antidiabetic agents
metoclopramide is contraindicated for 2 patients?
Contraindicated in patients with suspected small bowel obstruction;
Parkinson disease (because metoclop. blocks D2 receptors)
Serotonin receptor antagonists (5-HT3 antagonists) agents?
Ondansetron
Granisetron
Dolasetron
Palonosetron
ondrastenon mechanism?
5-HT3 antagonist
ondrastenon location of effect in brains?
Strong central antiemetic effect at the area postrema
ondrastenon peripheral inhibition?
Peripheral antiemetic effect via inhibition of the vagus nerve (decr. vagal stimulation)
ondrastenon - STRONG CENTRAL-ACTING ANTIEMETIC
.
Ondansetron is commonly used for generalized nausea.
.
Serotonin receptor antagonists
(5-HT3 antagonists) indications?
postoperative nausrea and vomiting (PONV) and in patients undergoing chemotherapy/radiation.
Serotonin receptor antagonists
(5-HT3 antagonists) adverse?
headache, constipation,
!!!!QT interval prolongation –> tdp
increase in liver enzymes
!!SEROTONIN syndrome
Anticholinergic agents?
Scopolamine
scopolamine mechnaism?
Nonspecific muscarinic antagonist
Central antiemetic effect at the area postrema and on the vestibular system
Peripheral antiemetic effect via inhibition of the vagus nerve
scopolamine indications?
Motion sickness, vestibular-induced nausea, and vomiting
scopolamine adverse?
Anticholinergic side effects: dry mouth, mydriasis, tachycardia, urinary retention
Antidote: physostigmine (cholinesterase inhibitor)
Neurokinin receptor antagonists. agents?
Aprepitant
Fosaprepitant
Aprepitant mechanism?
NK1 antagonist: Inhibition of NK1 receptors in the solitary nucleus → central antiemetic effect
Substance P antagonist: Additional inhibition of substance P-induced vomiting due to antagonism
aprepitant, location of action in the brain?
solitary nucleus –> central antiemetic effect
Aprepitant. indication?
Chemotherapy-induced nausea and vomiting (CINV) prophylaxis.
Aprepitant. adverse?
Gastrointestinal: diarrhea Fatigue Hypersensitivity reactions Infusion site reactions Increased levels of other drugs due to weak CYP3A4 enzyme inhibition
Antihistamines. agents?
Meclizine Dimenhydrinate Diphenhydramine Doxylamine Promethazine
antihistamines, mechanism?
H1 antagonist
Central antiemetic effect at the area postrema and VESTIBULAR system
antihistamines indications?
Strong sedative
Nausea and vomiting due to vestibular causes
Hyperemesis gravidarum (also see antiemetics during pregnancy)
antihistamines adverse?
Antihistamine effects: drowsiness and confusion
Anticholinergic side effects: dry mouth, dilated pupils, blurred vision, reduced bowel sounds, and urinary retention (antidote: physostigmine)
