Final exam lecture 6 Flashcards
Name two stimulant laxatives with dosing
Senna (2 tabs 1-2 x daily)
Bisacodyl (1-2 tabs daily)
MOA of stimulant laxatives
locally stimulate enteric nerves which stimulates contraction and mobility and increases fluid secretion into lumen
advantage vs disadvantage of stimulant laxatives
ADVANTAGES
Drug of choice for opioid induced constipation
quick onset
works` in pts with motility disorders
DISADVANTAGES
Risk of nausea and cramping
Avoid long term use in pts with normal GI activity
Stimulant laxative for very quick onset
Bisacodyl suppositories
drugs used for chronic isiopathic constipation after all else fails
Lubiprostone
Linaclotide
Plecanatide
Lactitol
Therapeutic options for acute constipation relief within 1 hr
Enema (saline, tap water or soap duds)
Bisacodyl or glycerin suppository
Therapeutic options for acute constipation relief within 3-6 hours
Citrate of ,agnesia
Larger PEG dose
Therapeutic options for acute constipation relief within 24 hrs
Bisacodyl or senna tabs
Therapeutic options for acute constipation relief within 48 hrs
milk of magnesia
PEG
1st step in Step therapy for chronic constipation
Step 1- relieve acute constipation (are there dietary modifications?)
2nd step in Step therapy for chronic constipation
Bulk forming laxative + fluids
3rd step in Step therapy for chronic constipation
Miralax
4th step in Step therapy for chronic constipation
Short term use of stimulant then maintainence agent
when to follow up for acute vs chronic constipation
1-2 days for acute (suppository- anticipate results in a couple hours)
( stimulant a few hours)
1-2 weeks for chronic
pharmacologoc treatment for constipation in special populations (spinal cord injury, pregnant, diabetic)
Spinal cord injury pts- usually on suppository stimulants
pregnancy- diet, fiber docusate
diabetic- prokinetic agents (metoclopramide) or stimulants
patients on opioids- stimulants, then add docusate, lactulose or PEG prn (AVOID BULK LAXATIVES)
treatment for opioid patients onstipation
-Stimulants, then add docusate, lactulose or PEG prn
-If nothing else works use METHYLALTREXONE
-Naloxegol
Treatment for diabetic patients that are constipated
Prokinetic drugs (metoclopramide) or stimulants
What is naloxegol used for? Dosing?
Used in treatment of opioid induced constipation.
25 mg QD (1 hr prior to 1st meal or 2 hours after meal)
(high fat meal increases extent and rate of absorption)
GI prep procedure
Clear liquid diet
large quantities of fluids
oral prep agents for GI procedures
PEG (nulytely, Golytely)
Refrigerate
most effective laxatives to soften stool
Bulk laxatives
List 5 common causes of nausea
Influenza
CNS disorder
Pain
Pregnancy
Excessive intake of anything
Key pathways involved in pathophysiology of nausea and vomiting
Cortex- Anxiety, tumor
GI tract- receptors in GI tract send signals to brain
Vestibular- motion sickness
Common neurotransmitters involved in N/V
Muscarinic, histaminic, dopamine, serotonin, NK receptors
1st step to n/v treatment non- pcol
Put the gut to rest (avoid fatty, fried sweet or spicy foods)
idenntify drug/treatment causes of N/V
chemotherapy
radiation/anesthesia
anti neoplastic agnets
Name the classes of drug therapy for N/V
Antihistamines/cholinergics- meclizine, dimenhydramine, scopolamine (good for motion sickness) (not effective for chemotherpay nausea)
Dizziness, sedation, dry mouth, constipation, blurred vision
Phenothiazines- prochlorperazine, promethazine. Dizziness, sedation, dry mouth, constipation
Serotonin antagonists- ondansetron, granisetron, palonsetron
Metoclopramide
Advantage/disadvantage of various serotonin antagoists
All end with -setron
Ondansetron- multiple dosage forms
Granisetron- multiple dosage forms
Dolasetron- PO only
Palonosetron- longest DOA (half life is 40 hrs)
treatment of motion sickness
Scopolamine patches
Meclizine PO (30-60 min before needed)
dimenhydrinate PO (30-60 min befire needed)
Why do we not use zofran (ondansetron) for motion sickness
We use antimuscarinics/anticholinergics
It is not used for prevention, only tx
Treatment of N/V secondary to gastroenteritis or pain
Ondansetron
Promethazine
Treatment of post operative nausea and vomiting
Aprepitant (Emend)
Moderate-high risk- Treat with 1 or 2 agents
Highest risk- always use 2 agents (5 HT3 + metoclopramide)
always pre treat motion sickness T/F
True
Why is it that the newer agents (NK-1 antagonists and the serotonin antagonists) are more effective? name drugs from each class
They have both central and peripheral activity against receptors. Old ones were only central.
NK antagonists- aprepitant, fosaprepitant
Serotonin inhibitors- ondansetron etc
Predisposing factors for IBS
Female
lower Socioeconomic status
What is IBS
Abdominal pain associated with abnormal bowel movements
IBS diagnosis criteria
Recurrent abdominal pain or discomfort atleast 1 day/week in the previous 3 months
Must have 2 or more of the following
-increase in pain related to defectaion
-associated with change in frequency of stool
- associated with change in apperance of stool
Differentiate subtypes of IBS
IBS-C and IBS-D
IBS-C is constipation predominant
IBS-D is diarrhea predominant
Treatment of IBS-C
Increase fiber and fluid intake and add bulk forming laxative (psyllium (metamucil))
What to do if Psyllium (metamucil) does not work for IBS-C
Use anti-spasmodic or anticholinergic agent for GI symptom
Name bulk forming laxatives
Psyllium, peg
name antispasmodic/anticholinergic drugs
Dicyclomine, Hyoscyamine
Treatment of IBS-D
- dietary modification (low lactose/caffeine)
- Loperamide or anti-spasmodic agen (diyclomine)
What to do in IBS-D if loperamide or anti-spasmodic agents (dicyclomine) do not work
Eluxadoline, then rifampin
Name anti diarrheal drugs
Loperamide (imodium)- no effect on abdominal apin
Diphenoxylate (lomotil)
