Equine GI Pharmacology Flashcards
A cationic polypeptide with bactericidal activity against gram (-) bacteria.
Polymyxin B
To which portion of the endotoxin does Polymyxin B bind?
Lipid A
What are 2 side effects associated with Polymyxin B?
- Nephrotoxicity
2. Neurotoxicity
Is Polymyxin B bactericidal or bacteriostatic?
Bactericidal
A synthetic xanthine derivative, phosphodiesterase inhibitor.
Pentoxifylline
True or False: Polymyxin B has decreased bio-availability after repeated dosing.
FALSE - PENTOXIFYLLINE has decreased availability after repeated dosing.
Pentoxifylline suppresses TNF-alpha, ____, and ____ production.
- IL-1
2. IL-6
Dimethylsulfoxide is a what?
Radical scavenger
Dimethysulfoxide can cause hemolysis when?
- Given too concentrated
2. Given too quickly
True or False: All anti-endotoxic drugs are more effective if given before exposure to an endotoxin.
TRUE
What type of GI drug is Bismuth subsalicylate?
Intestinal protectant (Pepto-bismol)
What type of GI drug is Kaolin pectin?
Intestinal protectant
What do Bismuth subsalicylate and Kaolin pectin have in common?
Absorb toxins, anti-diarrheal
Activated charcoal absorbs toxins and drugs, preventing/reducing systemic absorption. You may follow administration with a laxative when?
30 minutes after
Medications other than activated charcoal should not be given until how long after activated charcoal administration?
3 hours
____ and ____ decrease absorption of activated charcoal.
- Dairy products
2. Mineral oil
What type of drug is Dimethylsulfoxide?
Anti-endotoxic drug
Di-tri-octahedral smectite is an intestinal absorbent that absorbs what 2 toxins in vitro?
- C. difficile
2. C. perfringens
What are 4 indications for the use of laxatives or cathartics?
- Relive simple impactions
- Decrease intestinal transit time
- Increase stool consistency with chronic diarrhea
- Lubricate passage of ascarids or sand
What is magnesium sulfate (epsom salt)?
Laxative - Osmotically draws water into the GI lumen
What is Dioctyl sodium succinate?
Laxative
How does Dioctyl sodium succinate work?
Stimulates net secretion of water, Na, Cl, and K
What are 3 adverse effects of Dioctyl sodium succinate?
- Abdominal discomfort
- Intestinal irritation
- Dehydration
When would you use Dioctyl sodium succinate?
Severe/refractory cases of impaction
What is mineral oil?
Mild laxative
How does mineral oil work?
Prevents the reabsorption of water
What would you use to prevent ascarid impactions in heavily infected foals at the time of deworming?
Mineral oil
What could develop if mineral oil is aspirated?
Severe granulomatous pneumonia
What is psyllium?
Bulk forming laxative
What is the main use of psyllium?
Treatment and prevention of sand impaction
Water can be utilized as a laxative. What is one side effect to the use of water?
Hyponatremia
Caution: do not leave an indwelling nasogastric tube in place for more than ___ days.
2 days
Leaving a nasogastric tube in place for more than 2 days may cause what?
Pharyngeal necrosis
What is aluminum/magnesium hydroxide?
Anti-ulcer medication
True or False: Aluminum/magnesium hydroxide can be used to treat gastric ulcers.
FALSE - aluminum/magnesium hydroxide is a preventative, but is NOT curative for gastric ulcers.
What is cimetidine?
Anti-ulcer medication
What is the MOA of cimetidine?
Antagonizes H2 receptors
What is ranitidine?
Anti-ulcer medication
What is the MOA of ranitidine?
Antagonizes H2 receptors
True or False: Ranitidine is effective in healing gastric ulcers.
TRUE
What is sucralfate?
Anti-ulcer medication (sulfated polysaccharide)
Sucralfate stimulates mucus secretion and increases what?
PGE synthesis
What is the MOA of omeprazole?
Irreversibly inhibits proton pumps (H/K ATPase pumps)
True or False: Omeprazole can be used both curatively and as a prevention of gastric ulcers.
TRUE
What is pantoprazole?
Anti-ulcer medication (second generation proton pump inhibitor)
What is misoprostol?
Anti-ulcer medication (prostaglandin E1 analog)
Misoprostol stimulates the production of ____ and ____.
- Mucus
2. Bicarbonate
Misoprostol inhibits the secretion of what?
Gastric acid
What are 2 adverse effects of misoprostol?
- Abdominal pain
2. Diarrhea
What are 4 indications for prokinetics?
- Delayed gastric emptying
- Post-operative ileus
- Cecal impaction
- Proximal enteritis
Lidocaine has prokinetic effects on the small intestine and ____.
Large colon
What 3 effects does lidocaine have?
- Anti-inflammatory
- Anti-arrhythmic
- Analgesic
With what 2 drugs does lidocaine interact?
- Cimetidine
2. Metronidazole
Lidocaine is beneficial in the treatment of proximal enteritis and what?
Post-operative ileus
What are 4 toxic effects of lidocaine?
- Muscle fasciculations
- Ataxia
- Collapse
- Seizures
What is erythromycin lactobionate?
Prokinetic (motilin receptor agonist)
Which parts of the bowel will erythromycin lactobionate work on?
- Stomach
- Ileum
- Cecum
- Pelvic flexure
What are 2 side effects of erythromycin lactobionate?
- Abdominal pain
2. Diarrhea
What is the name of the chemical that makes up cisapride?
Benzamide
What is the MOA of cisapride?
Increases acetylcholine release at myenteric plexus, promoting generalized increase in motility
What type of prokinetic is bethanechol chloride?
Synthetic muscarinic cholinergic agonist
What would an overdose of betansechol chloride case?
- Salivation
- Lacrimation
- Urination
- Defecation
(SLUD)
What type of prokinetic is neostigmine methylsulfate?
Acetylcholinesterase inhibitor
What is butylscopolammonium bromide?
Antispasmodic
What is one side effect of butylscopolammonium bromide?
Tachycardia
What type of antispasmodic is butylscopolammonium bromide?
Anticholinergic
Metronidazole is used to treat ____ in neonatal foals.
Clostridium perfringens
Metronidazole is used to treat ____ in foals and adults.
Clostridium difficile
What are 2 indications for the use of macrolide antibiotics in the horse?
- Proliferative enteropathy (Lawsonia intracellularis)
2. Pyogranulomatous enterocolitis (Rhodococcus equi)
Name 3 macrolide antibiotics.
- Clarithromycin
- Azithromycin
- Erythromycin
What would you use for the treatment of Lawsonia intracellularis in animals that develop diarrhea on macrolides?
Chloramphenicol
What is indicated for the treatment of Potomac Horse Fever (Neorickettsia risticii)?
Oxytetracycline
What is the one adverse effect associated with oxytetracycline?
Nephrotoxicity