Drugs - Treatment of NVDC (Kinder) Flashcards
ondansetron
Zofran
5-HT3 antagonist
Metoclopromide
Reglan
Substitued Benzamide
D2 receptor antagonist
Prochloperazine (Compazine)
Penothiazines
D2 receptor Antagonist
Diphenhydramine (Benadryl)
Antihistamine
Promethazine (Phenergen)
Antihistamine
Dronabinol
Cannabinoids
MOA of Serotonin 5 HT3 receptor antagonists
ondansetron is prototype
blocks central 5HT3 receptors (vomiting center and CTZ) and peripheral receptors (GI tract -viscera)
Therapeutice use of ondansetron
***Acute CINV
(chemo induced n/v)
(little or no efficacy in delayed CINV)
PONV and post-radiation NV
when do you dose adjust ondansetron
hepatic insufficiency
ADR’s of ondansetron
well tolerated; headache, dizziness, constipation
QT prolongation
MOA of D2 receptor antagonists (metoclopramide)
inhibits D2-like (D2, D3, D4) dopamine receptors in the CTZ and solitary tract nucleus
Additional actions: 5-HT3 antagonism & prokinetic (nausea and vomiting peripherally)
prokinetic- results in peristalsis
therpeutic use of metoclopramide
CINV
diabetic gastroparesis
ADR’s of metoclopramide
Crosses BBB; extrapyramidal symptoms
-restless, dystonia (immature muscle contractions), parkinsonian symptoms
MOA of prochlorperazine
D2 receptor antagonist
inhibits D2-like (D2, D3, D4) dopamine receptors in the CTZ and solitary tract nucleus
Additional actions: antihistaminic and anticholinergic
therapeutic use of D2 receptor antagonist prochlorperazine
“General purpose” antiemetics
Motion sickness
what are the ADR’s of prochlorperazine
Hypotension, sedation, extrapyramidal symptoms
(don’t use post-operatively b/c you don’t want to make them more sedated)
hyperprolactinemia
MOA of diphenhydramine and promethazine
histamine, H1 receptor antagonists
Additional actions: anticholinergic and some antidopaminergic
Therapeutic use of diphenhydramine and promethazine
Motion sickness
PONV (post-op)
Vertigo
what are the ADR’s of antihistamines
dizziness,
sedation
dry mouth
urinary retention
*anticholinergic effects
MOA of scopalamine
MOA: muscarinic cholinergic receptor antagonist
therapeutic use of Scopalamine
motion sickness
ADR’s of scopalamine
better tolerated as a patch (behind ear)
often used for fisherman, people on boats
don’t use PO
MOA of cannabinoids (dronabinol)
and therapeutic use
stimulation of central CB1 receptors
therapeutic use:
- appetite stimulant
- antiemetic
what are the drug drug interactions of cannabinoids (dronabinol)
DDIs: potentiate effects of other psychoactive agents
what are the ADR’s of cannabinoids (dronabinol)
euphoria, dysphoria, sedation, hallucinations
autonomic- tachy, orthostatic hypotensino
NK1 receptor antagonists (aprepitant, fosaprepitant)
MOA
inhibits binding of substance P
acute phase of CINV is believed to be mediated by 5HT and substance P
while delayed CINV primarily due to substance P
therapeutic use of NK1 receptor antagonists
acute and delayed CINV
what drug do NK1 receptor antagonist decreased effectiveness
warfarin— can lead to clotting
what are therapeutic uses of corticosteroids in N/V
dexamethasone
increases the efficacy of 5-HT2 antagonists for acute and dealayed CINV
PONV
treatment combination for acute CINV
5HT3 receptor antagonist + NK1 receptor antagonist + glucocorticoid
what is the treatment for anticapatory n/v
benzodiazepine -> sedative properties reduce anxiety
what are the drugs used in PONV
5-HT3 receptor antagonist + dexamethasone
dimenhydrinate (if sedation desired)
prochlorperazine- less sedation
metaclopramide if above don’t work
what drugs are used for motion sickness
dimenhydrinate
promethazine
scopalamine
gastroparesis treatment
metoclopramide (D2 receptor antagonist)
pyridoxine use
pregnancy N/V
Loperamide
opioid
anti-diarrheal
bismuth subsalicylate
mucosal protective agent
anti-diarrheal
what are the osmotic laxatives
saline laxatives
polyethylene glycol
MOA of loperamide
stimulates μ-opioid receptors; increase transit time, increase fecal water absorption, decrease motility
non-prescription opioid
does not cross BBB (no CNS side effects)
no analgesic properties
no potential for addiction
Therapeutic use of Opioid agonists (Loperamide)
Nonspecific treatment of diarrhea
Traveler’s diarrhea
Adjunct in chronic diarrhea
ADR”s of loperamide
well tolerated
CNS effects at high doses (so use atropine added to discourage abuse)
CI in C. diff and active IBD due to risk of toxic megacolon
Psyllium
MOA
bulk forming laxative
indigestible, hydrophilic colloids which absorb water. Bulky emollient gel distends colon promoting peristalsis.
used for long term prevention
ADR’s of psyllium
bloating and flatulence
stool surfactant (softeners)
Docusate**
MOA:
allows water and lipids to penetrate stool which softens it
Ineffective for treatment but useful for prevention
helpful to prevent straining – > MI, after rectal surgery, etc.
MOA of osmotic laxatives
saline (mag citrate) polyethylene glycol (sugar)
soluble, non-absorbable, increase stool liquidity due to increase in fecal fluid
when do you not use anti-diarrheal agents
bloody diarrhea
high fever
systemic toxicity
Senna (Stimulant Laxative)
MOA
MOA: direct stimulation of enteric nervous system
therapeutic use of Stimulant laxatives
Not 1st line, recommended for intermittent use
Administer in lowest effective dose for shortest period of time
Long-term in neurologically impaired, bed-bound in long-term care facilities ***
Severe constipation with non-modifiable risk factors
Metoclopramide (Prokinetic)
MOA and therapeutic use
central and peripheral dopamine (D2) receptor antagonist; a serotonin (5-HT4) agonist; a serotonin (5-HT3) antagonist (at high doses); and a cholinesterase inhibitor
↑ motility of upper GI tract & ↑ gastric emptying;
antiemetic
Treats gastroparesis and GERD
lactulose used for what
hepatic encephalopathy
what is used for bowel prep for colonoscopy
polyethylene glycol
mag citrate
Softens stool is 1-3 days
Bulk forming laxatives
Stool softeners
Osmotic laxatives
- lactulose
- polyethylene glycol
softening of semi-fluid stool in 6-12 hrs
Senna
Mag sulfate
watery evacuation in 1-6 hrs
mag citrate
polyethylene glycol
MOA of Methylnatltrexone
selective inhibition of mu (opioid) receptors
does not cross BBB
inhibits peripheral receptors without affecting analgesia
therapeutic use
-opioid induced constipation in pt’s receiving palliative care for advanced illness
CI: GI obstruction
in pt’s with chronic renal disease and HTN problems , what drug do you want to avoid
sodium phosphate oral solution (osmotic laxative)
serotonin
binding in the periphery of 5HT3–> N/V
what is first line treatment for constipation prevention
bulk forming laxatives
docusates (Stool softeners)
what are sorbitol, lactulose, and magnesium hydroxide
osmotic laxatives
how long does it take for osmotic active agents to cause bowel evacuation
1-3 hrs
sodium phosphate
type of drug
ADR’s
osmotic laxative
frequently causes hyperphosphatemia, hypocalcemia, hypernatremia, and hypokalemia
can lead to cardiac arrythmias or acute renal failure
don’t use in frail or elderly, renal insufficiency , cardiac disease, or those unable to maintain adequate hydration
in comparison to sorbitol and lactulose what does polyethylene glycol not do
does not produce significant cramps or flatus
also designed so no significant intravascular fluid or electrolyte shifts occur
