true or false. Disease-induced changes of GI tract and liver can influence body homeostasis
TRUE
What is the primary route for drug administration?
GI tract
_______ of the top 50 drugs prescribed in US are agents used for management of GI problems, and some are available OTC
7
Why is it so important to consider drug effects and the medical condition the drug is managing, and especially questioning the pt regarding drugs managed OTC?
because pts often fail to report the intake of OTC drugs unless specifically questioned by the clinician.
What is the main symptom of GERD? What commonly brings on this symptom, and what might this pain mimic? What is a good way to prevent this from occuring during DH appointment?
substernal burning pain radiating up to neck
brought on by positions encouraging reflux: lying flat, supine position, stooping after meal
may mimic: cardiac pain, chest pain when stooping after eating or lying flat
Don't treat pt immediately after meals
What are 4 common complications of GERD? What are 2 things that might exacerbate these complications?
Medical treatment for GERD consists of what 2 things?
neutralizing stomach contents, or reducing gastric acid secretion
What are 4 common meds used to help neutralize stomach contents or reduce gastric acid secretion in pts with GERD? and what 2 conditions can they treat?
H2-receptor blocking agents: ranitidine (Zantac)
proton pump inhibitors: omeprazole (Prilosec)
sulcralfate
cisapride
They are all equally effective to treat: GERD and PUD
What are 2 agents that are commonly used in the maintenance treatment of reflux esophagitis?
omeprazole alone
omeprazole in combination with cisapride
Which type of drug's mechanism of action is that of antihistamines that block receptors in the GI tract, they inhibit action of histamine at receptors of parietal cells, and include; cimetidine, nizatidine, ranitidine, and famotidine.?
H2-receptor blocking agents (for GERD and PUD)
Cimetidine, nizatidine, ranitidine, and famotidine are all H2-receptor blocking agents, are they sold OTC?
yes
What are 5 ADEs for cimetidine, nizatidine, ranitidine, and famotidine (H2-receptor antagonists used for GERD and PUD)?
headache
lethargy
confusion
depression
hallucinations
What are 2 possible drug interactions with cimetidine (Tagamet) an H2-receptor blocking agent?
it inhibits the activity of hepatic cytochrome P450 enzymes: may interfere with hepatic metabolism of many drugs
ketoconazole, fluconazole, and tetracyclines may be decreased
What are 2 possible drug interactions with ranitidine, an H2-receptor blocking agent?
decreases absorption of diazepams
bupivacaine and benzodiazepine toxicity is possible
which drug is the prototype for the Proton Pump Inhibitors?
omeprazole
Which type of drug's mechanism of action is to bind to proton pumps of parietal cells and inhibits final step in secretion of hydrogen ions into the gastric lumen?
proton pump inhibitors
proton pump inhibitors are approved for ___________ treatment of peptic ulcers
short-term
What are the most effective Proton pump inhibitors available for acid suppression?
omeprazole and others
Why is there a concern for lont-term use of proton pump inhibitors?
they have a carcinogenic potential
List 5 available proton pump inhibitor agents.
omeprazole magnesium: Prilosec
lansoprazole: Prevacid
pantoprazole: Protonix
esomeprazole magnesium: Nexium
Rabeprazole: AcipHex
Which type of drug might increase blood levels of some azole antifungals owing to tablet dissolution in the presence of a high gastric pH; so you should avoid concomitant administration of the 2 drugs, and take them about 2 hours apart.
Proton Pump Inhibitors
What is the drug-drug interaction of proton pump inhibitors with enteric-coated salicylates?
it causes a rapid dissolution of them: increasing the gastric side effects of the salicylates
true or false. PPI drugs might inhibit the activity of some hepatic P450 enzymes, decreasing the clearance of some drugs. This effect may cause dental drug interactions with what 3 drugs?
true
diazepam, flurazepam, triazolam - may cause toxicity
Is it ok to use PPI's with enteric-coated aspirin?
NO
Name 2 cytoprotective agents.
sucralfate
cisapride
Which of the cytoprotective agents is an aluminum hydroxide of sucrose and has effectiveness in healing peptic ulcers and relapse; which is related to its topical affect via negative charged sulfate groups?
sucralfate
true or false. There are no known serious side effects to sucralfate; but it may decrease the absorption of other drugs
TRUE
Which of the cytoprotective agents is a prokinetic agent, but was removed from the market owing to dangerous drug interactions, but may be available for compassionate use only?
cisapride
What condition is characterized by erosion of the gastric or duodenal mucosa by acid and pepsin?
peptic ulcer disease (PUD)
What are 6 factors that exacerbate PUD condition?
stress
alcohol
cigarette smoking
NSAIDS
helicobacter pylori
genetic factors
What are the 2 main causes of peptic ulcer disease (PUD)?
infection of Helicobacter pylori
chronic ingestion of NSAIDS
The normal gastroduodenal mucosa resists injury from acid and pepsin in the gastric juice by __________ ___________ ________
homeostatic defense mechanisms
What do NSAIDS and Helicobacter pylori infections do to cause problems in the GI tract?
they disrupt the mucosal resistance to injury
What is a major drug-disease interaction associated with peptic ulcer disease?
ulcerogenic effects associated with NSAIDS: epidemiologic studies indicate the tx with NSAIDS increases risk of ulcer complications such as GI bleeding and perforation.
What is an example of a prostaglandin analog that prevents gastric ulcers in patients on chronic NSAID therapy, and does so by increasing mucin and bicarbonate release?
misoprostol
What is the most common adverse affect of the prostaglandin analog Misoprostol?
dose-related diarrhea
What are 4 symptoms of peptic ulcer disease?
pain: principle symptom
pt may have history of remission
vomiting may occur with PUD: question pt concerning recent history of vomiting
Pt predisposed to hemorrhage, perforation, and pyloric stenosis
What are the 3 primary types of drugs used to manage PUD?
antibacterial chemotherapy
administration of H2 receptor blocking agents: reduce gastric acid secretion
antacids: neutralize stomach contents
What are 4 other medical treatments/strategies for PUD not including the 3 primary ones?
agents that increase gastric emptying rate
preventative coating of the stomach
anticholinergic agents
endogenous prostaglandins
What are 4 common drugs used in antibacterial chemotherapy for the treatment of PUD?
tetracycline
metronidazole
amoxicillin
clarithromycin
often used in combination with an H2 receptor blocker or omeprazole and a coating agent
Antacids can be effective in promoting the healing of duodenal ulcers, their efficacy is based on their inherent ability to reacti with and _________________________________
neutralize gastric acid
The following are antacids used to heal duodenal ulcers; what is the risk from each of these?
sodium bicarbonate
calcium salts
aluminum salts
magnesium hydroxide
sodium bicarbonate: potential risk to cause systemic alkalosis and sodium overload
Calcium salts: may cause hypercalcemia
Aluminum salts: may cause constipation
Magnesium hydroxide: laxative effect
Which type of drug has the 3 following interactions with other drugs?
increases gastric pH, which may alter tablet dissolution, ionization, and gastric emptying time; absorption of weakly acidic drugs is decreased, and weekly basic drug absorption is increased, possibly resulting in toxicity
Adsorbing or binding drugs to their surface, resulting in decreased drug absorption or effect
increasing urinary pH, affecting the rate of drug elimination. excretion of basic drugs is decreased, and acidic drug excretion is enhanced
antacids
What is the most useful anticholinergic drug used to treat peptic ulcer disease? and how may it be used?
propantheline: Pro-Banthine
used as adjunctive therapy in combination with antacids, but not as a single agent
The timing of taking anticholinergic drugs and antacids is CRITICAL! When should each be taken?
antichlinergic drugs: 30 minutes BEFORE meals
antacids: 1 hour AFTER meals
What are 3 side effects and contraindications for the use of the anticholinergic drug propantheline in the treatment of PUD?
prostatic hypertrophy
urinary retention
cardiac arrhythmias
true or false. anticholinergic agents are rarely used in the tx of PUD. Why?
TRUE
because of their low efficacy and undesireable side effects
Which type of drug used to treat peptic ulcer disease has the mechanism of action of inhibiting muscarinic actions of acetylcholine at postganglionic PANS neuroeffector sites; and this response is dose-related; a large dose is required to inhibit acid secretion.
anticholinergic drugs
What is the passage of excessively dry stool, infrequent or insufficient size of stool?
constipation
What are 6 major causes of constipation?
functional abnormalities
colonic diseases
rectal problems
neurologic disease
metabolic conditions
administration of many different drugs
Constipation in most nonhospitalized pts can be resolved by doing what 2 things?
eating high fiber diets
supplement diet with bulk-forming agents
Bulk-forming agents and saline laxatives are used for the medical treatment of what condition?
constipation
Bulk-forming agents and saline laxatives may be classified into what 2 things?
organic hydrophilic colloids: methylcellulose, calcium polycarbophil, psyllium, bran, and fruits
What agent is commonly used to prepare for colonoscopy and enhances the cleaning of the GI tract over a 12-hr period when used as directed?
magnesium citrate
bulk-forming agents and saline laxatives are more effective when administered with what?
water
Irritants are used in the medical treatment of constipation. Name 5 irritants used
danthron
castor oil
senna
bisacodyl
phenolphthalein
true or false. Most irritants used in the treatment of constipation are SLOW in their onset of action
true
What agents may produce systemic problems by the resulting effect on electrolyte and water balance because they affect the environment in the GI tract?
irritants
Lubricants are also used to medically treat constipation. list 4 lubricants used.
mineral oil
docusate
glycerin
lactulose
Which agents used to treat constipation may inhibit absorption of fat soluble vitamins and other essential nutrients if used chronically?
lubricants
What is defined as an associated fecal urgency and incontinence, passage of liquefied stool with increased frequency?
diarrhea
What are the 3 usual causes of acute diarrhea?
infection
drugs
toxins
Viral or bacterial induced diarrhea is usually __________ and requires only a clear liquid diet and increased fluid intake
transient
List 4 antidiarrheal agents, and the drugs listed under each category.
opioid agents/anticholinergic agents: diphenoxylate and atropine (Lomotil); Loperamide (Imodium)
What is a motility disorder involving the entire GI tract, causing recurrent abdominal pain and bloating, diarrhea, and/or constipation.
Irritable Bowel Syndrome
What is the cause of IBS?
unkown
true or false. In the medical management of IBS, it is important to increase dietary fiber.
true
What are 2 drugs that are given in the medical management of pts with IBS diarrhea? and when is it given?
diphenoxylate or loperamide
given before meals
What is a drug given for medical management of IBS as a short-term drug for women when the primary symptom of their IBS is constipation?
tegaserod maleate (Zelnorm)
Where is the vomiting center, which is the origin of the final common pathway along which different impulses induce emesis?
lateral reticular formation of the medulla
What is the second important medullary site in regards to vomiting center?
chemoreceptor trigger zone
__ blocks the chemoreceptor trigger zone, the second important medullary site
phenothiazine
What are 8 things that might activate the vomitting center?
impulses from pharynx
impulses from GI
impulses from cerebral cortex
emotional trauma
unpleasant olfactory stimuli
unpleasant visual stimuli
stimulation of the vestibular apparatus
What are 4 effects of protracted vomitting?
electrolyte imbalance
malnutrition
dehydration
upper GI laceration
What agents mechanism of action includes; blocking dopaminergic receptors in the CTZ of medulla; and abolishing emetic responses caused by a variety of stimulants
antiemetic agents
What are 3 reasons that antiemetic agents are used for?
vomiting
motion sickness
anxiety-induced emesis
What are the 2 most common agents to reduce vomiting?
promethazine: Phenergan
metoclopramide: Reglan
What is the action of Dopamine (D2) antagonists?
they are antiemetic agents
___________ and _________ are adverse effects of variety of drugs in cancer chemotherapy and general anesthesia; these effects can be reduced with the use of ____________ drugs
nausea
emesis
antiemetic
Which type of drugs block dopamine (D2) receptors in the CTZ, and have been shown to effectively abolish the emetic response due to some cancer chemotherapeutic agents, general anesthetics and other agents, and radiotherapy?
Phenothiazines
What drug is used to control anesthesia-induced emesis (which is dose dependant); but it may induce extrapyramidal effects and can complicate intraoral procedures (especially radiographs)
the phenothiazine (Promethazine)
which type of drug is both D2 and 5-HT3 receptor antagonists; at higher doses reduces cisplatin-induced emesis, but their use is limited by antidopaminergic side effects?
What is the name of a cannabinoid that is effective in pts receiving moderately emetogenic chemotherapy? It is administered before infusion of chemotherapeutic agents and it increases the appetit, produces euphoria, and has analgesic properties, which make it useful in pts with terminal cancer and as appetite stimulant in HIV disease?
Dronabinol: Marinol
What are 3 ADEs with the cannabinoid drug Dronabinol (Marinol)?
dizziness
drowsiness
lack of concentration
What type of drug that is used to reduce nausea and vomiting has a weak antiemetic action; but it is administered in combination with high-dose metoclopramide to reduce extrapyramidal reactions?
antihistamines
What are 5 common examples of antihistamines used in combination with high-dose metoclopramide in the tx of nausea and vomiting?
cetirizine: Zyrtec
chlorpheniramine maleate: Chlor-Trimeton
loratadine: Claritin
desloratadine: Clarinex
diphenhydramine hydrochloride: Benadryl
true or false. Antihistamines have proved useful in the treating emesis associated with motion sickness.
true
What type of drugs are the drug of choice to reduce nausea and vomiting in the first trimester of pregnancy? can you use them in the 3rd trimester? What are 2 side effects of these?
antihistamines
NO
drowsiness and dry mouth
What are 2 anticholinergic (antagonists to acetylcholine) drugs that have proven useful in treating emesis associate with motion sickness?
scopolamine (Transderm-Scop): administered as a patch
propantheline bromide (Pro-Banthine): administered as a tablet
What are examples of ADEs that may occur with the short-term use of anticholinergics used for nausea and vomiting? And for long-term therapy?
short term (1-3 days): drowsiness and xerostomia
long-term (more than 3 days): candidiasis
What type of drugs are prescribed for urinary incontinence, or an overactive bladdar?
urinary antispasmotics
What are 3 examples of the main agents used as urinary antispasmotics? (which are anticholinergic drugs?
detrol LA
ditropan
enablex
What are 3 dose-forms that anticholinergic urinary antispasmotics are available in?
tablet
extended-release tablet
capsule
What are 4 common ADEs associated with the use of urinary antispasmotics?
dry mouth
dry eyes
tachycardia
constipation
What type of drug's mechanism of action has a direct effect on smooth muscle, inhibits muscarinic action of acetylcholine on smooth muscle; and diminishes the frequency of contractions and delays desires to void, urgency, and frequency of incontinent episodes?
Oxybutynin chloride: a urinary antispasmotic
Which type of drug inhibits urinary bladdar contractions and salivation by blocking effect on cholinergic muscarinic receptors; and drugs such as erythromycin, clarithromycin, and azol antifungal agents (cytochrome P450 3A4 inhibitors) require dose reduction when used in conjugation with this drug?
Tolterodine tartrate: a urinary antispasmotic
What are 4 clinical management problems that might be caused by Gastroesophageal disorders?
positioning: semisupine position
caries
chemical erosion: lingual surfaces
xerostomia
When narcotic analgesics are prescribed, the pt should be informed of the potential for what?