N/V/D/C/IBS Flashcards
(115 cards)
N/V causes?
GI irritation, motion sickness, vestibular dz, hormone imbalance, drugs and radiation, exogenous toxins, pain, psychogenic factors, intracranial pathology
N/V clinical presentation?
everyone aware of. dehydration can occur: inc. thirst and dry mouth, less frequent urination, tachycardia, pinching skin takes longer to go down (dec. turgor)
What is the N/V non-pharm tx?
rehydrate (ORS = oral rehydration solutations), avoid dairy, BRAT diet 24 hrs. after fluid only (banana, rice, apple sauce, toast dry)
What are the types of N/V Pharmacologic tx?
- 5-HT3 Antagonists
- Dopamine Antagonists
- Antihistamines
- Cannabinoids
What are the 5-HT3 Antagonists and how do they work?
Ondansetron (Zofran) used Granisetron (Kytril) Dolasetron (Anezmet) MOA: antagonism of the 5-HT4 receptor in the chemo-receptor trigger zone (CTZ) Route: PO, PR, IM, IV
What are the 5-HT3 Antagonists indications and ADRs?
Indications: tx and prevention of postoperative N/V, chemo-induced N/V
ADRs: HA (common), dizziness, diarrhea, abdo pain
What are the Dopamine Antagonist and how do they work?
Metoclopramide (Reglan)
Trimethobenzamide (Tigan)
Phenothiazine (Prochlorperazine - Compazine)
MOA: antagonist of D2 receptors in CTZ, at higher doses metoclopramide also block 5-HT3 receptors. Also promotes gastric emptying and small intestine peristalsis = prokinetic effects!!!
What are the Dopamine Antagonists CIs and ADRs?
CI: GI - hemorrhage, obstruction or perf (d/t prokinetic effects), caution in pts w/depression, pheochromocytoma, seizure, caution in kids
ADRs: extrapyramidal effects (d/t blocking DA - parkinson-like effects), restlessness, anxiety, drowsiness, fatigue, hallucinations, CV: HTN, HPOTN, AV block, bradycardia, agranulocytosis
Name the types of Antihistamines and how they work?
Promethazine (Phenergan), Phenothiazine
MOA: blocks H1 –> effectiveness appears to be w/motions sickness and vestibulocochlear dz, antagonist of D2 receptors in the CTZ.
Dose: 12.5-25 mg Q4hr. PRN, IV, PO, PR (MUST be diluted with NS for injection, dangerous in extravasation)
What are the ADRs and cautions for Antihistamines
ADRs: dry mouth, dizziness, Parkinsonian symptoms (dyskinesia, dystonias, akathisia, neuroleptic malignancy syndrome (life threatening), blood dyscrasias. Caution in BPH, urinary retention, glaucoma
Cannabinoids can be used to treat N/V and what is it called/side effects, etc?
Dronabinol (Marinol), MOA not well defined.
Side effects: drowsiness, sedation, inc. appetite
What is normal motility of the intestines called and what does it do?
peristalsis, acts to mix bowel contents thorougly, to propel them in the caudal direciton
Regulation of normal intestinal motility is under control of what?
neuronal and hormonal
What classes of drugs are used to affect GI motility
laxatives, antidiarrheal agents, prokinetic agents, antiemetic agents, antispasmodics
What is the definition of constipation
2 or more of: straining >25% of time, lumpy/hard stools >25% of time, feeling of incomplete evacuation >25% of time, 2 or fewer BM in 1 week
What are some causes of conatipaiton?
Metabolic: hypothyroid, hypercalcemia, hypokalemia
GI disorder: tumors, IBS, diverticulitis
Pregnancy
Neurogenic: trauma to brain/spinal cord, CNS tumor, Parkinson’s
What are some meds that cause constipation
Opiates (most), Ca and Al antacids, Fe, Ca++ channel blockers (Verapamil), Clonidine, Anticholinergics (antihistamines, antiparkinsonians, TCA)
What are some non-pharm tx/management/prevention of constipation
drink plenty of H20/fluids, “P” jucies, adequate exercise, high fiber diet including: insoluble - shorten intestinal transit time and inc. stool bulk (whole grains/bran); water soluble fiber: more moist stool and less effect on transit time (fresh fruits/veggies)
What are laxatives used for?
hasten transit time in the gut and encourage defecation. Also used to clear bowel prior to medical and surgical procedures
What are the laxatives from lecture?
bulk-forming laxatives emollients and lubricants saline cathartics osmotic laxatives stimulant laxatives
What are the bulk forming laxatives?
Psyllium (Metamucil)
Methylcellulose (Citrucel)
Polycarbophil (Fibercon)
What is the MOA of bulk-forming laxatives and their onse?
inc. volume of non-absorbable solid residue w/water, distending colon and stimulating peristaltic activity, inc. rate of colonic transit . adequate fluid intake is important while taking these. onset: 2-3 days?
For which type of patients are bulk-forming laxatives considered first line? What are some CIs?
bedridden or geriatric w/chronic constipation. also good in pregnancy
CI: pts w/stenosis, ulceration or adhesions, fecal obstruction
What are the ADRs and DIs for bulk-forming laxatives?
ADRs: flatulence, abdo distention, gastro obstruction
DI: binds to drugs and reduces absorption - separate from other meds