Antiemetics- Fitz Flashcards
When is IPECAC particularly dangerous?
If suspected poison is:
Corrosive
Petroleum distillate
Rapidly-acting convulsant
Where is CTZ found? Is it inside the BBB?
CTZ is found in brainstem but it is OUTSIDE of the blood brain barrier
Are antiemetics more effective at preventing vomiting or stopping emesis once its started?
Preventing vomiting
What are the only truly effective agents for cancer chemotherapy-induced emesis?
5HT3 antagonists = “SETRONS”
Which agent is most effective for motion sickness?
Scopolamine
How must scopolamine be administered?
As a TRANSDERMAL PATCH
Otherwise has high incidence of anticholinergic side effects
MOA of scopolamine?
Antimuscarinic
Inhibits muscarinic receptors in the cerebellum
Rapidly and fully distributes to CNS
Good for MOTION SICKNESS
Must be given as transdermal patch
Use for activated charcoal?
Binds toxins
Absorbs many drugs/poisons due to its large surface area
Use for polyethylene glycol electrolyte solution?
Cathartic
May hasten removal of toxins and reduce absorption
What things should you NOT use activated charcoal for?
Does not bind
Iron
Lithium
Potassium
Binds alcohol and cyanide poorly
What kind of drug is IPECAC?
Emetic - local GI irritant effect as well as acting on CTZ
Which antiemetic is best used in pregnancy?
?
When is an NK1 antagonist used?
Prevention of acute and delay phase of chemotherapy induced nausea and vomitting
What is typically given in combination with NK1 antagonist?
5HT3 antagonist and dexamethasone
For chemotherapy induced vomiting
What is a specific side effect of NK1 antagonist?
Drug-drug interactions!
Metabolized by CYP3A4
Decreases metabolism/increases toxicity of:
Warfarin
Cisapride!
Some chemotherapy agents
What three classes of antiemetics MUST cross BBB to be effective?
H1 receptor antagonists
NK1 receptor antagonists
Cannabinoids
