Nausea/ vomitting/ diarrhea/constipation Drugs Flashcards
Treatment of Nausea and vomitting-non pharmacological
Rehydrate, avoid dairy, BRAT diet 24 hours after strict fluid diet
What are the 4 types of therapy for N/V
5-HT3 antagonists,
antihistamines,
dopamine antagonists,
cannabinoids
5- HT3 antagonists
- Ondansetron-specific for CINV and PONV
- Granisetron
- Dolasetron
note: work specifically in chemo receptor trigger zone
what are the 5-HT3 antagonist indications?
treatment of PONV and CINV
What are the ADR’s of 5-HT3 antagonists?
- HA,
- Dizziness,
- Diarrhea,
- Abdominal Pain
What are the 3 dopamine antagonists
- Metoclopramide-specifically has pro kinetic affects approved by the FDA
- trimethobenzamide
- Prochlorperazine
What is the DA MOA
antagonize D2 receptors in the CTZ,
- at higher doses metoclopramidde also blocks 5-HT3 receptors
- metoclopramide also has pro kinetic affects in the gastric and small intestine
What are the Dopamine antagonist contraindications?
GI hemorrhage obstruction of perforation cautious in its with pheochromocytoma seizure -caution in children
what are the Dopamine antagonist ADRs
Extrapyramidal effects, Restlessness, Anxiety, drowsiness, fatigue hallucinations
Cardiovascular symptoms such as, HTN, HPOTN, Adblock, Bradycardia, AGRANULOCYTOSIS
What is the drug used as an Antihistamine
Promethazine
What is the MOA of antihistamines for N/V
block H1-effectiveness appears to be specifically with motion sickness and vestibulocochlear diseases, specifically antagonize d2 receptors in the CTZ
What are the ADR;s of Antihistamines for N/V
- dry mouth, dizziness
- parkinsonian symptoms (dyskinesia, dystopias, akathisia
- neuroleptic malignant syndrome
What are the contraindications of antihistamines for N/V
benign prostatic hypertension
urinary retention
glaucoma
What is the function of cannabinoids in nausea and vomitting
canabanoids- specifically dronabinol in this case, helps to stimulate appetite and control nausea and vomitting. MOA is not well defined
what are the side effects of dronabinol
-drowsiness, sedation, increased appetite.
What are the classes of drugs that affect intestinal motility?
- laxitives
- antidiarrheal
- prokinetic agents
- antiemetic agents
- antispasmodics
What is the medical definition of constipation?
2 or more of the following symptoms:
- straining >25% of the time
- lumpy or hard stools >25% of the time
- feeling of incomplete evacuation >25% of the time
- 2 or fewer BM in 1 week.
What are some causes of constipation?
Metabotropic-hypothyroid, hypercalcemia, hypokalemia, diabetes
GI disorders-tumors, IBS, diverticulitis
Pregnancy
Neurogenic-traume to the brain/spinal chord, CNS tumor, Parkinsons
List some meds that would cause constipation?
- opiates
- Ca and Al antacids
- Iron
- calcium channel blockers
- clonidine
- anticholinergics-antihistamines, antiparkinsonians, TCAs
What are some non pharmacological treatments for constipation
1 best way- drink plenty of water and fluids
- Adequate excercse
- high fiber diet
What is the purpose of laxatives?
Hasten the transit time in the gut and encourage defamation. They also clear the bowel prior to medical and surgical procedures
What are all the types of laxatives listed in lecture? (5)
- bulk forming laxatives
- emollients and lubricants
- saline cathartics
- osmotic laxatives
5 stimulant laxatives
What are the bulk forming laxatives?
- Psyllium (metamucil)- good for diabetics due to sugar free nature
- Methylcellulose
- polycarbophil
How do bulk forming laxatives work?
They cause the bulk of the feces to increase by increasing water volume which distends the colon and stimulates peristaltic activity. thus increasing the rate of colonic transport time. -be careful to intake fluid vigorously while on these
What are bulk forming laxatives indications
- these are considered 1st line for bed ridden its, elderly patients with chronic constipation, and pregnancy
Why can’t bulk forming laxatives such as psyllium be used?
if a person has stenosis, these cannot be used as well as if the person has ulcerations/adhesions, and fecal obstructions
-this is because build up in these conditions would be really bad for the pt.
what are some of the ADR’s of Bulk forming laxitives
- flatulance
- abdominal distinction-bulk forming duh
- gastrointestinal obstruction
what are some of the drug interactions of bulk forming medications
- bulk forming laxatives will bind to other drugs and inhibit them from working properly by reducing absorption, thus they must be separated 2 hours before other meds or 6 hours after other meds
Why can they also be used
they can relieve mild constipation, and relieve IBS symptoms, they can also lower cholesterol
What is the drug we think of as an Emollient?
docusate sodium
What is the purpose of an emolient
These will break up fecal material and fat by emulsifying the pooh and preventing straining in people with Recent MI, rectal surgery, on opiates, or those who are PREGNANT which can be used along side bulk forming laxitives
What is the MOA of an decussate sodium- an emollient?
it works mainly with surfactant by bringing water into the stool, which facilitates mixing of aqueous and fatty materials within the intestine, increasing H20 and electrolyte secretion in small/large bowels.
Why would you not use and emollient such as Doccusate sodium
if you already had fecal impaction or if you had signs and symptoms of appendicitis.
What is the lubricant we talk about the most?
Mineral oil
What is the main indication for mineral oil
mainly used for prevention of straining and after MI, rectal surgery, but not for chronic use
What is the MOA of of Lubricants such as mineral oil?
it coats the stool, allowing easier passage, and inhibits colonic absorption of water
Why can you not use mineral oil?
Avoid use of mineral oil in elderly, if there is an aspiration risk and watch for a decrease in the absorption of fat soluble vitamins ADEK.
What is a gross complication of mineral oil?
Anal leakage
What are the different saline cathartics?
think salts; magnesium hydroxide (milk of magnesia),
- magnesium sulfate (epsom salts)
- Sodium phosphate (fleets enema)
- magnesium citrate (citrate of magnesia)
how do these saline cathartics like MOM work?
these salts are poorly absorbed and thus increase the water content of the bowl through osmosis
Do not use saline cathartics if:
the patient has impaired renal function which causes mg and NA accumulation, if CHF, and in HTN its due to their lack of sodium capacity
How does Castor oil work?
Home remedy, never prescribed which is metabolized to ricinoleic acid which in turn stimulates the secretory pathways. This also decreases glucose absorption, promotes intestinal motility and is not for routine use.
how do you use a glycerine suppository?
MOA: this has osmotic actin in the rectum only. And causes rectal irritation but is generally very safe and often used on constipated kids
Why and how do you use a glycerine/ hyper osmotic such as polyethylene glycol or miralax?
works as an osmotic, relatively safe and used in Kids
Golytely is another glycerine hyper osmotic that is used, but what is its use specifically
this is specifically used to cleanse the colon before diagnostic procedures are done. this is the one where you must drink 4 L in 3 hours and do so on the toilet. AVOID in patients with intestinal obstruction
There are 2 stimulant laxatives listed in the lectures; what are they?
diphenylmethane derivative: Bisacodyl
anthraquinone laxative: Senna; increases peristalsis.