Question 13 - Pharma
What is the function of Bismuth subsalicylate ?
It decreases fluid secretion in the bowel
How do the stimulant laxatives increase peristalsis?
Stimulate nerves in colon Inhibit Na pump --> inflow of electrolytes to lumen Secondary stimulation of peristaltic movements in small intestine and colon
How is glycerol a laxative?
Taken as suppositories, it has effect after 15-30 minutes
How is the bulk laxatives given?
Tea Effect in 24hours, maximal effect after 2-3days
How does the bulk laxatives work?
They form gels in the large intestine, causing water retention and intestinal distention, leading to increased peristaltic activity.
When does lactulose work ?
12-24hours
What is Castor Oil ? - How does it work - Who should not use it=
A agent broken down in the small intestine to "Ricinoleic acid", which is verry irritating to the GI and causes rapid peristalsis. Should be avoided in pregnant, can stimulate uterine contraction
What is phenolphtalein ? - side effects?
A laxative (calcium channel inhibitor, I think..) Effect after 10-14 h Works in enterohepatal circulation, effect for several days Side effect: Coloured stool and rash
How does the chloride channel activators work?
Activation of chloride channels to increase fluid secretion in the intestinal lumen. This eases the passage of stools and causes little change in electrolyte balance.
4 different mechanisms of therapy in diarrhea?
Adsorbent therapy - Decrease exposition to toxins Decelerate motility Elimination of infectious pathogens Colonize bowel with good bacterial flora
When can probiotics be a good therapy?
After antibiotic treatment, having caused dysmicrobial flora. Culture of non-pathogenic strains of E.coli and Saccharomyces
Name 4 drugs that are "adsorbents" ?
Aluminium hydroxide Methylcellulose Carbo adsorbens = Kaoline Diosmeticum (Smecta) = Magnesium-aluminum silicate (favorite drug, high adsorbent capacity)
What can Riaximin be used for?
Antibiotic For treatment, less suitable for prevention because resistance develops fast. Bacteriostatic and cidal G+and G- spectrum
Which drug is great for traveler's diarrhea?
Bismuth Subsalicylate
Adverse effects of Bismuth Subsalicylate?
Black tongue, black stool
How does aluminium hydroxide and Methylcellulose work?
By adsorbing intestinal toxins or microorg. or by coating and protecting the intestinal mucosa.
What can Nifuroxazide be used for?
Chemotherapeutic - Suitable for prophylaxis
What is the result when taking Ioperamid?
Decrease tonus of small intestine Increase tonus of m. sphincter ani Decrease secretion into GIT
Two drugs that are "antimotility agents" ?
Diphenoxylate Loperamide
Name two stool softeners? "Emollient laxatives"
Docusate sodium Docusate calcium
Side effects of bulk laxatives?
Flatulency
What else can lactulose be used as therapy for?
Hepatic encephalopathy
What are they made of ?
Hydrophilic colloids from indigestable parts of fruits and vegetables.
When should imodium not be used ?
If there is blood in the diarrhea, or if there is fever together with the diarrhea
what is the common name of the drug Loperamide?
Imodium It is not resorbed in the gut, works only locally
5 causes of acute diarrhea?
Infection Drugs Ischemic colitis Thrombosis of mesenteric artery or vein Acute diverticulitis
What are some contraindications of laxatives?
Inflammatory bowel disease Acute Abdomen Chronic abuse of laxatives
Some side effects of stimulant laxatives?
Intestinal cramps Secondary slack of intestine /flaccidity
Groups of laxatives?
Irritants/Stimulants Bulk laxatives Saline/Osmotic laxatives Stool softeners Lubricant laxatives Chloride channel activators
What is Senna Glycoside ?
It is a laxative useful for treating opioid induced constipation. Taken orally it causes evacuation of bowel within 8-10hours. Taken by rectum: evecuation of bowel within minutes Only short term use The medication is taken by mouth or via the rectum
How does the antraquinone laxative work ?
It travels unchanged to the colon, where it is hydrolyzed by bacteria, and antracens are released. This leads to stimulation of the myenteric plexus, and blockage of the reabsorption of sodium. Senna derivatives are a type of stimulant laxative and are of the anthraquinone type.
How do the nonabsorbabe salts work?
Keeping the water in intestine by osmosis, leading to distention of bowel and increasing intestinal activity and defecation within few hours.
Name one chlorid channel activator?
Lubiprostone
Name som examples of non-absorbable salts?
Magnesium citrate Magnesium hydroxide Magnesium sulphate
Name some causes of constipation?
Mechanical obstruction Functional obstructions Metabolic disorders Dehydration Innervation disorders Autonomic dysfunction Drugs
Name some bulk laxatives?
Methycellulose Agar Seed coat of ribgrass
Name two lubricant laxatives?
Mineral oil and glycerin suppositories Facilitation of passage of hard stools
What are these stool softeners used for?
Mostly for prophylaxis rather than acute treatment, may take days to become effective
Why is Lubiprostone a good drug?
No tolerance or dependency has been reported Minimal drug-drug interactions
Which drugs can be called bowel germicidal agents?
Non absorbable chemotherapeutics Non absorbable antibiotics Works mostly on pathogens, less of the physiological flora - antibiotics - antimycotics - antiprotozoic
How to treat travellers diarrhea?
Non specific therapy 1. rehydration 2. Bowel adsorbent - disometicum/Carbo absorbens 3. Antiomotility - Iopermiade 4. Probiotics
Name 4 different types of saline and osmoatic laxatives?
Non-absorbable salts Polyethylene glycol Lactulose Glycerol
How long can you use the stimulant laxatives?
Only for a few days
Which receptors does diphenoxylate and Loperamide work on?
Opioid receptors type u
What are some indications of laxatives?
Painful emptying Severe constipation, bothering the patient Medical examinations Accelerate passage during intoxication
On which bacteria does Cloroxine work, and what type of drug is it ?
Quinolone *chemotherapeutic* agent Effect on Gram+/Gram- bacteria
How does these two drugs (Diphenoxylate and Loperamide) work on the gut?
They have opioid like actions on the gut Activating presynaptic opioid receptors in the enteric nervous system, and inhibit Acetylcholine release --> decreased peristalsis
How should we treat diarrhea?
Treat the cause, not only the symptoms!
Statement: Diphenoxylate and Loperamide does not have opioid /analgesic effect ?
True
When do we use polyethylene glycol?
colonic lavage solution to prepare gut for radiologic or endoscopic procedures Effective 1-3 hours
Name some irritant/stimulating laxatives?
Senna Bisacodyl Castor oil Phenolphtalein
How to treat a obstipated patient? 1st, 2nd and 3rd step
1st: - Increase fiber - increase physical activity - rehearse defecation reflex - low amount of osmotic laxatives 2nd: Increase dose of osmotic laxative, add contact/irritative laxative (Bicasodyl) 3rd: - Add laxative according optimal individual effect
How long can Cloroxine be used?
4 weeks, if longer --> Neurotoxic
How fast do the stimulant laxatives work?
4-12 hours
What is Bisocadyl ?
= DULCOLAX A potent stimulator of the colon, acting directly on the nerve fibers in mucosa of the colon. Tablets for night --> morning effect Suppository morning dose --> effect after 15min-1h
Which drugs can cause constipation?
Anticholinergic drugs and sympathomimetic drugs Opioids Calcium channel blockers Diuretics (Dehydration) (and many more)
5 causes of chronic diarrhea?
Inflammatory Osmotic (disorders of absorption - pancreatic insuff) Secretory (ZE syndrome, carcinoid sy) Motility disorder (irritable bowel, neurologic disorders) Artefact - abuse of laxatives
Why is lactulose a laxative drug?
It cannot be hydrolyzed by GI enzymes, so it acts as a osmotic laxative In the colon it is degraded by colonic bacteria --> lactic, formic and acetic acid, which increases osmosis
What is the function of irritant/stimulant laxatives?
They increase peristaltic movement