Nausea, Vomiting - Dwyer

NV-Inducing Drugs

Cancer drugs, antibiotics, inhaled anesthetics, hypoglycemics (SUs, insulin), OCPs, opioids, digoxin, anticonvulsants, caffeine

3 Major NV risk factors

Chemotherapy, surgery/anaesthesia, pregnancy

Non-Pharm/Alternative NV Treaments

Diet, acupuncture, ginger, pyridoxine (B6)

PONV Prevention in Children and Patients with NO Risk Factors

No drugs

OR

Dexamethasone OR 5HT₃RA

PONV in patients with 2+ risk factors

Use 3 to 4 drugs of different classes

Which antiemetic should be used either the evening before or 1-2 hours before surgery? Which should be used during induction? Which should be used after induction? Which should be used at the end of the procedure?

Evening/1-2 hours before: scopolamine patch

During induction: NK1s

After induction: dexamethasone

End of surgery: ondanestron

Which agents should be used for rescue therapy with PONV? Which practices are ineffective? Which medications should not be repeated specifically?

Ideal rescue therapy agents: phenothiazine OR metoclopramide OR droperidol (these are all D2 antagonists)

Avoid: repeating the agent given for prophylaxis within 6 hours of surgery (ineffective), repeat doses of scopolamine or droperidol

Which 5HT3RA(s) oral only? IV only? Multiple dosage forms?

PO only: dolasetron, alosetron

IV only: palonosetron

Multiple: ondansetron, granisetro

Which 5HT3RA is the gold standard? What is its max IV dose?

ondansetron —> max 16 mg IV

Which 5HT3RAs are the longest acting? Which should be used at the end of the procedure?

Longest-acting: granisetron, palonosetron

Use at end of surg: ondansetron

Which 5 adverse effects are of particular concern for corticosteroids?

Hyperglycemia, edema, insomnia, mood changes, infection risk

What’s the recommended dosing range for dexamethasone?

4-10 mg, more commonly 4-8 mg

What are the dopamine antagonists used in NV? Which category is most useful for simple NV? Which is used for CINV and PONV? Which is pro-kinetic?

Metoclopramide, amisulpride, Phenothiazines (prochlorperazine, chloropromazine, chloropromazine), Butyrophenones (haloperidol, droperidol).\

Simple NV: phenothiazines (not first line but acceptable)

CINV/PONV: butyrophenones, especially haloperidol for breakthrough CINV and PONV prophylaxis

Prokinetic: metoclopramide

What is the cutoff for chronic use of dopamine antagonists with risk of EPS? Which D2A should have an EKG used with it? Which D2A should not be used in undiluted boluses? Which carry hypotension risk? Which carry elevated prolactin risks?

Chronic use cutoff: >12 weeks

Use EKG: droperidol (butyrophenone > phenothiazine > metoclopramide)

Incompatible for undiluted bolus: promethazine

Hypotension: buytrophenones, phenothiazines

Elevated prolacting: metoclopramide (gynecomastia risk), amisulpride (lower risk)

Which drugs are used more for anticipatory and anxiety-related NV?

Benzodiazepines (BZDs)

How should scopolamine patches be used for motion sickness prevention? Preoperative nausea prevention?

Motion sickness: 1 patch behind ear 2-4 hours before event, change every 72 hours prn

Preop: 1 patch the night prior to surgery or 1-2 hours prior to surgery THEN remove 24 hours after surgery

Which agents are THC analogs? Which receptor do they target? What is their primary role in practice?

agents: nabilone, dronabinol

receptor: CB1

role in practice: refractory CINV, breakthrough NV

Which antiemetic classes can be used in pregnant patients?

When be considered for treatment refractory pregnancy-NV, and at what point in the pregnancy?

Pyridoxine ± doxylamine = FLT, 5HT3s, H1RAs, promethazine, metoclopramide

For severe refractory or hyperemesis gravidarum, can use dexamethasone

only after 10 weeks gestation, increased risk of cleft li

What’s ideal NV therapy for children? What’s first line antiemetic?

Ideal therapy is oral rehydration with no drugs. If antiemetic needed —> ondansetron

Promethazine contraindication

under 2 years, risk of fatal respiratory depression

Preferred antiemetic in older adults

ondansetron