What stimulates the GIT and what inhibits it?
GABA stimulates, serotonin (5-HT) inhibits it
What is considered to be a more effective appetite stimulant in cats, but not in dogs, with pronounced sedation effect?
What is an antihistamine agent with anti-serotonin properties, is an appetite stimulant drug for cats, inhibits serotonin receptors, which control appetite?
What is the preferred anti-obesity drug in dogs, blocks the assembly and release of lipoproteins into the blood stream, inhibits fat absorption from small intestine?
Afferent input into the emetic center arrives from what 4 sources?
chemoreceptor trigger zone, vestibular system, peripheral sensory receptors, higher central nervous system centers
What is not protected by the blood brain barrier and therefore sensitive to the blood-borne toxins?
What type of neurotransmission plays a role in Chemoreceptor Trigger Zone (CTZ)
Afferent input travels via what cranial nerve to the vestibular nucleus and arrives to the emetic center after passing through CTZ?
cranial nerve VIII (vestibulocochlear)
What is the primary neurotransmitter mediating the emesis from peripheral receptors?
Neurotransmission from higher CNS center is mediated by what?
cholinergic and histaminergic transmission
What can induce emesis in dogs?
saturated solution of table salt, hydrogen peroxide, ipecac syrup
Should ipecac syrup be used in cats?
What is a derivative of morphine, effective emetic in dogs, produces marked excitement in cats, so this drug is not recommended in cats?
Why is the conjunctival route more preferred in apomorphine?
because tablet can be removed once animal vomits
What is an a2-adrenergic receptor agonist, centrally acting emetic in cats, dose required to produce emesis in cats is low compared to dose required from tranquilization, side effect is bradycardia?
What blocks primarily H1 receptors at the vestibular apparatus and secondarily at the CTZ and the emetic center?
What mediated emesis due to motion sickness or inner ear disease, side effects include xerostomia, drowsiness?
What can penetrate the BBB and can be used to control motion sickness in dgs, are contraindicated in cats?
What are a2-adrenergic receptor antagonists, with antidopaminergic and weak antihistamine and anticholinergic properties, are broad spectrum antiemetics and control emesis induced by most of the central causes except labyrinthine stimulation?
When are phenothiazines contraindicated?
in animals with seizures (lowers the threshold)
What drug has potent antiemetic activity because of their antidopaminergic activity?
What is a dopamine and 5-HT serotonin receptor antagonist, effectively antagonizes ampomorphine-induced emesis an is 20 times more potent than phenothiazines?
What drugs block neurotransmission in the CTZ and also interfere with the action of serotonin on peripheral receptors in the GIT
peripheral 5HT3, serotonin antagonists
What can control emesis induced by cisplatin, chemotherapeutic agents/radiation treatment in dogs, cants and ferrets?
What are drugs that protect the GI epithelium from gastric irritation, can act as antiemetic drugs?
peripherally acting antiemetics
The anticholinergic drugs exert its antiemetic activity by?
inhibiting vagal afferent impulses, relaxing GI smooth muscle spasms, inhibiting gastroenteric secretions
What is the major drawback of anticholinergic drugs?
delays gastric emptying
The secretion of gastric acid by the parietal cells of the gastric mucosa depends on what 3 endogenous agonists?
histamine, acetylcholine, and gastrin
What modulate the effect of histamine by decreasing adenylyl cyclase activity and thereby decreasing the conversion of ATP to cAMP resulting in decreased production of gastric acid?
prostaglandins PGE2 and PGI2
What is an antimuscarinic agent that produces a selective action on gastric M1 receptors, inhibits food-induced gastric acid secretion by 50-60% with less antimuscarinic side effects
What is the order of potency in gastric inhibitors?
famotidine > rantitidine = nizatidine > cimetidine
What H2 receptor antagonist is the prototype drug, undergoes hepatic metabolism and is about 70% bioavailable following oral administration?
What H2 receptor antagonist is less bioavailable as compared to cimetidine, absorption is not impaired by food?
What is rapidly and completely absorbed from GIT with excellent bioavailability, eliminated exclusively by renal excretion in unchanged form, is preferred H2 receptor antagonist in hepativ disease conditions?
What H2 receptor antagonist inhibits cytochrome P450 system and interferes with the metabolism of concurrently administered drugs, is clinically useful in preventing acteaminophen toxicity in cases of accidental overdose?
What is the most common side effect of H2 receptor antagonists?
rebound acid hypersecretion
What is a proton pump inhibitor, that irreversibly inhibits the H+, K+-ATPase proton pump on the gastric parietal cell, drug dissolution occurs in the alkaline environment of small intestine, and is absorbed from the duodenum?
Omeprazole can be used in combination with what for the eradication of helicobacter pylori infections in humans?
clarithromycin and ampicillin
What is an important adverse reaction of omeprazole?
omeprazole-induced hypergastrinemia causes parietal cell hyperplasia and hypertrophy of gastric mucosa
What is well absorbed after oral administration, it does not alter the serum gastrin levels, hence it prevents rebound acid hypersecretion?
What are aluminum preparations often mixed with to prevent constipation?
What is the antacid of choice in the treatment of mild ruminal acidosis?
What is a systemic antacid, is water soluble, induces alkalosis condition, overuse may result in the rapid liberation of carbon dioxide and lead to gastric distention?
What are side effects of systemic antacids?
constipation, diarrhea, hypercalcemia, hypophosphatemia
What is a prostaglandin E1, acts as a gastric cytoprotective agent, enhanced mucosal blood flow, stabilizes mast cells and is considered to be a potent agent in gastroduodenal ulcer healing?
What is a prostaglandin E1, acts as a stimulus for the synthesis of local mediators PGs and sulfhydryl ions, binds epidermal growth factor, increases mucosal blood flow by inducing local nitric oxide or PG production or by directly stimulating mucosal angiogenesis?
Why should sucralfate not be administered concurrently with antacids, H2 receptor antagonists or proton pump inhibitors?
it requires an acid environment (pH < 5)
What are drugs that can increase GI motility and transit of intraluminal contents?
What enhances the amplitude of contractions throughout the GIT including the lower esophageal sphincter?
When should cholinergics not be administered?
when there is mechanical obstruction of the intestine or urinary tract, in animals with peritonitis, if intestinal wall is less viable
What enhances the release of ACH from cholinergic neurons of myenteric plexus of the enteric NS and also sensitizes the intestinal smooth muscle cells to the action of ACH?
What are clinical indications of metoclopramide?
reflux esophagitis, gastric motility disorders
What is the broadest spectrum of action of the prokinetic agents, increases activity at all sites of GIT, enhances release of ACH and cholinergic neurotransmission in myenteric plexus, 8X more potent than metoclopramide, not a dopamine antagonist?
What is the main action of antimuscarinics in diarrhea?
ability to reduce intestinal secretions
What is a parenteral preparation and used as an antispasmodic to control diarrhea in calves and for the management of mild colic in horses?
hyoscine butylbromide - metamizole combination
What drugs inhibit motility as wella s secretions, increases tone of the sphincters so intestinal propulsive activity is markedly reduced, but contraindicated when diarrhea is due to invasive bacterial infection?
Why are opioids contraindicated when diarrhea is due to invasice bacterial infection?
opioids prolong intestinal transit time, thus increases the contact time for proliferation of bacterial infection
What opioid is not used with cats because overdosage causes marked exciteability with other clinical signs such as mydriasis, goose stepping gait, and loss of balance?
What GI protectant undergoes metabolic transformation in GIT, releases salicylate, which is then absorbed into systemic circulation, dose in cats should be cautiously determined, and along with charcoal can absorb E. coli enterotoxins?
What is used for emergency treatment of poisonings, has large surface area so it can rapidly absorb drugs and poisons?
What is a basic anion exhange resin that binds to acidic side chains of bile acids, insoluble in water, not absorbed and not affected by digestive enzymes, clinically indicated for pruritis?
Chronic use of this emollient laxative may impair absorption of fat-soluble vitamines (ADEK), and development of granulomatous lesions in the intestinal wall and rarely in liver?
Accidental administration of mineral oil into the trachea and bronchial tree may lead to what?
What is a hydrophilic mucilloid, most common bulk-forming laxative used in equine practice, promotes the movement of impacted ingesta through the colon and is useful in treating impactions caused by ingestion of sand?
What purgatives are contraindicated in dehydrated animals?
Even though magnesium ion is poorly absorbed, the amoutn absorbed could produce toxicity in what?
animals with impaired renal function
Repeated administration of this drug causes superpurgation in horses, it is excreted through milk sufficient to effect nursing animals?
Neuromuscular purgatives should not be recommended when?
in any mechanical obstruction of the intestine
Why should enema preparations that contain phosphate should not be used in cats?
they can precipitate potentially fatal hyperphosphatemia, hypocalcemia, and hypernatremia in cats
What is dietary in origin and occurs when leguminous plants or high grain diets are ingested, decreased secretion of saliva exacerbates this?
What is a non-ionic surface active agent that may be used both for the treatment and prevention of frothy bloat?
What type of oils are contraindicated in frothy bloat because they stabilize the foam?