GIT pharms Flashcards
1
Q
Appetite stimulants
A
- Used mostly in anorectic cats
2
Q
Cyproheptadine
A
- Antihistamine (H1 blocker) with anti-serotonin (serotonin antagonist) properties
- Not used for antihistamine effects!
- Given 12hr IV or per os
3
Q
Mirtazapine
A
- Tricyclic antidepressant with α2 and serotonin antagonist properties
- Good in cats
- SE: sedation
4
Q
Diazepam/midazolam
A
- Stimulates GABA release
- OID as need, avoid frequent use
- SE: sedation, slows down gastric emptying, hepatotoxicity
5
Q
Drugs to dry up salivary secretion
A
- Most commonly used are the anti-muscarinic drugs, used for pre-medication purposes
• E.g., atropine, glycopyrrolate and scopolamine
• Less effective in ruminants than monogastrics - Side effects
- Tachycardia
- Dry mouth (xerostoma)
- Constipation
- Pupillary dilation (mydriasis)
6
Q
Buccopharyngeal Washes/Antiseptics
A
- Used after tartar removal; stomatitis or gingivitis
- Should be non-irritant, non-toxic
- Various commercial solutions for veterinary use on the market
- Active compounds include: • 5% NaHCO3 • Hexetidine • Povidone iodine solution (Betadine) • Cetylpyridinium (Cepacol, C.E.T) • Chlorhexidine (Petdent)
7
Q
Parasympathomimetics to relax the oesophagus
A
- Neostigmine
- Muscarinic action; increases availability of Ach at the neuromuscular junction therefore increases peristalsis and salivation
8
Q
Anti-spasmodics to relax the oesophagus
A
• Proquamezine fumarate (Myspamol®); not commonly used
- Hyoscine butylbromide (Buscopan®)
- Doses available for extra-label use in most species
- Good for choke in horses
9
Q
Anti-ulcer drugs (H2 antagonists)
A
- Cimetidine
- Ramotidine
- Famotidine: proven efficacy in the dog
10
Q
- Omeprazole
A
- Non-competitive antagonist which binds irreversibly to H+K+ATPase pumps
- Takes 3 – 4 days to have an effect (especially orally)
- Given oid, but can be used bid
- Expensive
- Side effects; maldigestion
- Used in horses, dogs, cheetahs
- A proton-pump inhibitor
11
Q
Sucralfate
A
o A coating or binding agent
o Adheres to erosions/ulcers and binds bile-salts and pepsin
o Appears to increase mucosal blood supply
o Usually used in conjunction with H2-antagonists or for a few days with omeprazole
o Also a very good for prophylactic in dogs and can be beneficial for gastritis cases
o Side effects
- Can bind other drugs; administer 1 – 2 hrs prior to other drugs in multidrug therapeutic regimes
- Monitor for constipation
- Taste is a limiting factor
12
Q
Misoprostol (PGE analogue)
A
o A synthetic hormone o Decreases acid formation - Increase mucosal blood flow - Stimulates the gastric mucosa - Enhance mucosal defense mechanisms o Might be superior for NSAID-related prophylaxis therapy o SE: Abdominal discomfort, Abortions
13
Q
Apomorphine
A
- Can give any route; usually in the conjunctival sac
- Should vomit within 3 min
- Remove with saline after vomiting
- Repeated doses not very effective and suppresses CNS and VC
- DOC in dogs
14
Q
Xylazine
A
- Given IM
- DOC in cats
- Other drugs have emesis as a side-effect (alpha-2 agonists, opioids, methylxanthines)
15
Q
Maropitant citrate
A
- MOA: Directly inhibits vomiting by blocking substance P binding at the NK1 receptors in the emetic centre
- The only registered anti-emetic for dogs (injectable and tablets), in cats only injectable registered
- Safe and effective
- OID dosing; long receptor binding
- Treats vomiting from multiple causes
- Prevents vomiting due to motion sickness
- Also provides some visceral analgesia
- No adjustment needed in dogs with renal failure
- Side effects (rare): bone marrow suppression in puppies, pain on injection
16
Q
- Metoclopramide
A
- An anti-dopaminergics
- Commonly used (oral tablets and syrup, injectable)
- Can cause excitement in small dogs and cats
- Crosses BBB and can give extrapyramidal effects
17
Q
- Domperidone
A
- An anti-dopaminergic
- Cannot cross BBB to cause CNS and extrapyramidal effects
- Do not use when suspecting an obstruction
18
Q
Phenothiazines
A
- Multi-receptor antagonists: dopamine antagonists at lower doses (CTZ) and muscarine antagonists at higher doses (VC)
- Prochlorperazine (Stemetil)
ACP:
• Often used as a premed with morphine in dogs
• Causes hypotension –avoid/hydrate prior to use in shock/ dehydrated animals
19
Q
Anti-histamines as anti-emetics
A
- Antagonists at the H1 receptors in the vestibular apparatus and CTZ
- Cyclizine - good for motion sickness
- Diphenhydramine hydrochloride
20
Q
Anti-cholinergics
A
- Ideal for motion sickness
* Scopolamine/hyoscine butylbromide (Buscopan)
21
Q
Serotonin (type 3) antagonists
A
Antagonists at the CTZ, vomiting centre and in the GIT
Ondansetron (Zofran):
• Appears to be well tolerated by dogs
• Good for ICU cases not responding to metoclopramide
22
Q
Osmotic laxatives and saline salts
A
- Not absorbed therefore pull water into the GIT
- Lactulose is a safe, first choice for mild constipation**
- Can also use mannitol, glycerine or sorbitol
- Access to water is a must
- Magnesium sulphate (Epsom salt), Na2SO4 (Glauber’s salts, preferred in horses)
23
Q
Bulk forming laxatives
A
- Psyllium and sterculia, wheat bran, agar, carboxy methylcellulose
- Increases fecal bulk, stool softer
- Absorb water into the intestine, stimulate peristalsis
24
Q
Mechanical lubricants and emollients
A
- Petroleum products, some plant oils, liquid paraffin and surfactants such as dioctyl sodium succinate (Laxapet, Docusol)
- Mechanical lubricants and stool softeners
- Reduces surface tension and water reabsorption
- Also used for impaction colic in horse
25
Enemas
- Fluid or suppositories administered per rectum to break up faecal impaction
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Substances used:
• Warm soapy water
• Oily substances like glycerol and liquid paraffin
• Surfactants
• (Docusol and other commercial brands)
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26
Enzymes for Exocrine Pancreatic Insufficiency (EPI) (Pet-Assist, DigestEaze)
* Pancrealipase OR raw porcine pancreatic tissue
* Not to be heated
* Usually life-long treatment
27
Probiotics (Protexin and many formulations!)
• Useful for restoring GIT microflora after antibiotics
28
Antibiotics (acting local to GIT)
* Metronidazole
| * Effective against anaerobic bacteria and Giardia spp in large bowel diarrhoea
29
Buscopan
* Buscopan is the trade name
* Contains hyoscine butylbromide (also called scopolamine butylbromide)
* These alkaloids are anti-muscarinic and therefore causes GIT smooth muscle relaxation
* Pure scopolamine is found in the Solanaceae family of plants (Night shade)
* Datura spp
* Brugmansia spp (Angel’s trumpets)
30
Bio-Sponge for horses (Ditrioctahedral smectite)
* PO for intestinal support in diarrhoea cases
* Proven effect against Clostridium spp toxins
* Can combine with metronidazole
31
Metoclopramide
* Post operative ileus in rabbits
| * Upper GIT prokinetic
32
Cisapride (compounded)
* Effective in dogs and cats for gastro-oesophageal reflux
| * Feline megacolon; also has motility enhancement in the colon
33
Lignocaine
* Used in horses
* Indirect effect; prevents inhibitory effect on GIT motility
* Analgesic/ anti-inflammatory effect on the GIT
34
Amoxycillin and ampicillin (aminopenicillins)
* Prime candidates for disturbing normal GIT flora
* Suitable in treating cases of bacterial overgrowth due to anaerobic bacteria.
* If culture and sensitivity not available for animal in a critical condition due to sepsis can consider combination of parenteral penicillins plus an aminoglycoside (amikacin or gentamicin)
* Ensure that the patient is hydrated prior to using aminoglycosides
35
Potentiated sulphonamides
* Broad spectrum activity against invading aerobic and anaerobic bacteria
* Minimally disrupt intestinal flora
36
Sulphasalazine (sulpha-analogue)
* Bacteria in the colon split into sulfapyridine and mesalazine
* Sulfapyridine = sulphonamide antibiotic
* Mesalazine (5-aminosalicylic acid) = anti-inflammatory in the colon
* Used for treating colitis in dogs
* Need to use for at least six weeks
* Monitor for KCS
37
Metronidazole (nitroimidazoles)
* Broad spectrum of activity against anaerobic bacteria
* Anti-protozoal properties
* Seems to have immunomodulating properties in animals suffering from IBD
38
Tetracyclines
* Can be used for treatment of SIBO
| * Doxycycline excreted directly through the mucosa of the digestive tract
39
Lincomycin (lincosamides) and erythromycin (macrolides)
* Limited value in the treatment of diarrhea; disruptive effects on microflora and needless expense
* Erythromycin has a high incidence of drug induced vomiting
40
Fluoroquinolones
* Very effective at reducing the aerobic bacterial flora of faeces, generally without affecting the anaerobic flora
* Potent gram-negative activity with a lower but often therapeutically useful activity against gram-positive aerobes
41
Antacids; rumen acidosis
• DOC is MgO (Kyrogest)
- Not absorbed (non-systemic)
- Less CO2 produced than with alternative salts
• Note that proper dietary management and transition is important in preventing and managing rumen acidosis
• Ionophores can be used to modulate rumen microbial function
• Inhibit ruminal lactate producers
42
OTC products for bloat
* Poloxalene (Bloatguard)
| * Dioctyl sodium sulphosuccinate (Docusol): Also used to loosen earwax and as enema
43
On farm remedies for bloat
* Cooking oil (up to 2 cups per bovine)
* Liquid paraffin in milk (up to 60 ml per bovine)
* Non-foaming detergents (automatic washing machines)
44
Ruminotorics
* Establish a suitable rumen environment (Rumix)
* Multiple commercial mixes available
* Can also use molasses, glycerol, propylene glycol, brewer’s yeast, good quality hay, fresh ruminal contents (transfaunation)
* Always dose with large amounts of warm water and massage
45
Anti-zymotics
* suppress microflora and depresses rumen fermentation
* Not commonly used, but can work if animal has overeaten
* Antibiotics or protozoacides dosed orally, formalin, turpentine etc.
46
Zinc acetate or gluconate
• For patients with chronic hepatic disease or fibrosis
o Chronic liver disease tends to result in a zinc deficiency which may impair immunoregulatory functions and favour collagen deposition leading to hepatic fibrosis
• Reduces absorption of copper, so useful for Cu storage disease
• Assists with detoxification of ammonium
47
Ursodeoxycholicacid /ursodiol (Ursotan)
* Thought to modify the cytotoxicity of the bile acids thus decreasing hepatocyte death, inflammation and fibrosis
* Also thought to be directly cytoprotective to hepatocytes
* Expensive
48
Colchicine
* An antimitotic agent that inhibits synthesis of collagen, thus can be antifibrotic
* Questionable efficacy, and can have significant side effects (bone marrow suppression, haemorrhagic gastroenteritis or HGE)
49
Anti-oxidants
* S-Adenosyl-L-methionine (SAMe), allopurinol, desferroxamine
* The administration of S-adenosyl-L-methionine provides the substrate required for the continued formation of glutathione, a primary defense antioxidant in the liver and RBCs
50
Cholagogues
* A compound that stimulates gall bladder contraction and bile acid release
* May aid in fat digestion or for minor bile duct blockage?
* Dietary fats
51
Ceruletide
* A decapeptide similar to gastrin
* Acts at the CCK receptors to contract the gallbladder and relax the sphincter of Oddi
* Parasympathomimetics e.g. pilocarpine can also be used to promote contraction of the gallbladder
52
Choleretics
* Increases bile production by the hepatocytes
| * Ox bile extract, dehydrocholic acid, clanbutin, methoxynapthalene
53
Neomycin
* Reduces bacterial load
| * Reduces the intestinal production of ammonia from glutamine metabolism
54
Lactulose, used synergistically with neomycin
• Per os or as an enema in emergency
• Metabolised by gut microbes to low molecular weight organic acids
o Lactic acid, acetic acid, which acidify gut and trap ammonium ions (become ionized)
• Encourages bacterial nitrogen fixation
• Dose adjusted based on stool consistency and frequency
55
Essential phospholipids
• Assist with fat oxidation, anti-inflammatory, membrane protective, antifibrotic
56
Choline
* Precursor is SAMe
| * Assist with fat oxidation, DNA methylation, modulation of gene expression
57
Methionine
* Part of SAMe and precursor to choline
| * Antioxidant
58
Azathioprine
• Usually together with corticosteroids to lower dose if side effects develop
59
Metronidazole
• Inhibits purine synthesis; suppresses cell mediated immunity and changes antibody production
