Unit 4: antiinflammatories Flashcards

Question

How long does methylpredisolone acetate work

Answer 1

~7 days Methylprednisolone acetate (DepoMedrol®)– long-acting IM/SQ injectable; white suspension CANNOT give IV (30-40 day duration) ($)

Answer 2

28d Desoxycortisone pivalate (Percorten®)– long acting injection for treating Addison’s ($$$$)

Answer 3

Most commonly used. Indicated for Chronic low dose (anti inflammatory activity) for allergy,a asthma arthritis IV injection for anaphylaxis

Answer 4

Two forms of the same drug Prednisone is a prodrug (inactive form) Prednisone is converted by a liver enzyme to prednisolone (active form) Cats and horses are not very efficient at this conversion, should be given prednisolone

Answer 5

Can't be on NSAIDs Can't stop drug abruptly Will interfere with lots of testing Lots of side effects PU/PD/PP (owner should be informed) GI upset-ulcers Immunosuppression Poor healing if going into surgery

Answer 6

Always find out what the current dose is if long term use. Lots of PRN (as needed) use. Write in as part of history Always inform owners of common, expected side effects (increased appetite, PUPD, panting) Always inform owners of needing to wean off Concurrent use of steroids and NSAIDs are contraindicated. Watch out for allergic patients and older, arthritic patients Low dose steroid therapy will not affect vaccine efficacy Names sound similar, so be careful when selecting the drug from the pharmacy. Know which ones are IV use, which are suspensions, prednisone versus prednisolone Depending on the steroid, requires 1-4 months from time meds are stopped until all physiological effects of drugs are gone

Answer 7

Anti Inflammatory and analgesia Work by blocking cyclooxygenase (COX) enzymes Stop production of prostaglandins and thromboxane

Answer 8

Turns on platelets for clotting Maintain blood flow to kidneys Turns on mucus production (protect from acid, digestive juices) Controls stomach acid production

Answer 9

Promotes inflammation Promotes fever Enhances pain signals Turn on tissue repair Turns on whaling of ulcers

Answer 10

NSAIDS are separated into 2 classes based on whether they inhibit: COX-1 and/or COX-2 Nonselective NSAIDs Older drugs Inhibit COX-1 and COX-2 Decreases inflammation, fever and pain signalling COX-2 selectives Different adverse effects

Answer 11

Newer drugs Inhibit COX-2; minimal to no COX-1 inhibition Purpose: to decrease unwanted side effects Reduced risk of GI ulcers, renal effects, antiplatelets effects Still some overlap wand will also inhibit COX-1 May decrease whaling of pre-existing GI ulcers

Answer 12

Effectiveness and adverse effects (i.e., tolerance) varies with drug, species and individual patient Some drugs are more appropriate for certain species than others All are metabolized in the liver All are eliminated in the kidneys (and slightly by biliary excretion) Toxicity is increased if liver or kidney disease

Answer 13

Human OTC Aspirin (acetylsalicylate acid, ASA) AVOID Equine /nonselective Ibuprofen (Motrin, Advil) Phenylbutazone (aka “-bute”) Flunixin meglumine (Banamine®) Naproxen (Equiproxen®) Ketoprofen Topical ophthalmic Diclofenac (Voltaren® SA/COX-2 selective Meloxicam (Metacam®) Carprofen (Rimadyl) Deracoxib (Deramaxx®) Firacoxib (Previcox®) –equine too Tolfenamic acid (Tolfedine®) Robenacoxib (Onsior®)– newest for cats

Answer 14

Decrease inflammation Analgesia One of most commonly used analgesics in vet med Mild to moderate pain 2 mechanisms: (1) decreasing inflammation and (2) inhibiting prostaglandin synthesis (prostaglandins make pain receptors more sensitive) Very good for pre-emptive analgesia Works synergistically with opioids Reduce fever (anti-pyretic) Different mechanism than the above

Answer 15

Stomach and intestinal ulcers Kidney damage Prevents healing of GI ulcers Decreases clotting, risk of bleeding Hepatotoxicity - rare

Answer 16

Severity of side-effects depends on which NSAID is prescribed and the patient Toxic effects increase with chronic use Cats susceptible to ALL adverse effects NSAIDs are metabolized by glucuronyl transferase Cats do not produce much of this enzyme Drug accumulates → increases toxic risk Ex. Metacam dose: 0.05 mg/kg (cat), 0.1 mg/kg (dog)

Answer 17

Use PRN (as needed) at lowest effective dose Never take more than one NSAID at a time Allow wash out period between NSAIDs Avoid use in patients on steroids Avoid use if kidney or liver disease Caution in dehydrated, hypoproteinemic patients Avoid concurrent use with nephrotoxic drugs Avoid use in patients that are dehydrated or hypotensive Avoid use in patients with existing GI ulcers, patients undergoing GI surgery Caution in cats Avoid in patients with bleeding disorders Especially aspirin Remember: Human OTC drugs require a prescription for ELDU use in any animal species.

Answer 18

Common Overdose (too much, too frequent) Wrong patient Inappropriate administration of human OTC products Vomit/diarrhea →bloody v/d, melena→kidney damage (vomit, PU/PD, anuria, Acute Respiratory Disease) → neurological signs Emergency IV fluids, diuresis, GI protectants, activate charcoal, liver protectants

Answer 19

COX non-selective Inhibits BOTH COX-1 and COX-2 enzymes Inhibition of COX-1 in platelets is irreversible Inexpensive, widely available as human OTC ELDU in small animal Primary use in vet med as an anticoagulant for management of blood clots (cats) There are better/safer drugs for treating inflammation and pain Requires glucuronyl transferase for inactivation

Answer 20

Easy to overdose in cats Cats metabolize very slowly t½ is 40 h in cats compared t0 7 ½ h in dogs Not used for inflammation control in Equine Due to short half life and GI side effects Decreases clotting; increased risk of bleeding Will increase risk of hemorrhage in patients undergoing surgery 21-days between last dose and any surgery (in dogs) Entric coated Aspirin – not recommended

Answer 21

Important explain that aspirin is not the same as other OTC human anti-inflammatories such as : Ibuprofen (Advil® ,Motrin®) Naproxen (Aleve®) Acetaminphen (Tylenol®) Clients should not replace the aspirin product with one of the above as it could produce severe side effects or death to their animal

Answer 22

Equine: treating musculoskeletal pain and laminitis Non-selective COX inhibitor A highly protein bound drug Many versions available Oral paste/tablet/powder; injectable In Canada Phenylbutazone is not labeled for use in food-producing animals including horses that are to be slaughtered for use in food.

Answer 23

Bone marrow suppression Resulting in neutropenia, thrombocytopenia and anemia Animals on Long term usage should be monitored regularly via hematology lab testing Tissue necrosis Occurs if IV dosage form is accidentally injected IM or SQ

Answer 24

Non-selective COX inhibitor Used for short-term treatment of moderate pain and inflammation in Large Animals Oral and injectable (IV only avoid giving IM even though is on label) Bovine Shipping fever and coliform mastitis - IV ONLY Equine COLIC - alleviates visceral pain musculoskeletal disorders Guinea pigs – off label **WDTs

Answer 25

Cox 2 Selective highly protein bound Oral (liquid suspension, tablets) and Injectable (has 30 min onset of action) Licensed versions for Dog, Cat, Cattle Used extra label in many exotic and zoo animals, including reptiles and birds, for treatment of pain and inflammation.

Answer 26

alleviation of inflammation and pain in both acute and chronic musculo-skeletal disorders Osteoarthritis Pain associated with surgery SQ (onset 30 min), then switch to oral (4 h onset) Oral absorption is almost complete in dogs when administered with food. The oral meloxicam solution of meloxicam contains xylitol Safe use of Oral Suspension in dogs younger than 6 months of age, dogs used for breeding, or in pregnant or lactating dogs has not been evaluated

Answer 27

following surgery or associated with acute, mild to moderate musculoskeletal disorders in cats. Peri-operative use may be administered once daily (at 24-hour intervals) for up to two days Acute musculoskeletal disorders for up to four days The safety of Metacam has not been evaluated in breeding, pregnant or lactating cats.

Answer 28

Use in cats is limited to short-term use Limited to single SQ injection post-operative for surgical pain The manufacturer (metacam®) does not recommend a second dose of meloxicam injection to cats.

Answer 29

Injectable and Oral solution available For alleviation of pain and inflammation Licensed for beef cattle not lactating dairy cows WDT 35 days from last treatment– slaughter

Answer 30

Prescription only Must be hydrated Caution in older animals Liver and renal values often required Needs monitoring if chronic use Show owners how to draw up oral dose Review dose size/volume with owners Give oral forms with food or 1 hour after Decreases risk of vomit/diarrhea; GI ulcer Do not give if not eating/drinking

Answer 31

Generic: carprofen COX-2 Selective In rare cases, carprofen has caused idiosyncratic acute hepatic toxicity in dogs. Signs of toxicity usually appear 2-3 weeks after exposure

Answer 32

Generic: deracoxib COX-2 selective Licensed versions for Dog (25, 75, 100 mg tabs), not cats 2 on-label uses: Osteoarthritic pain (chronic use) Post-surgical pain (up to 7d) Onset: 1-2 hour Oral form only Gastric ulceration (may be more common than some other NSAIDs)

Answer 33

(firocoxib) COX-2 selective To control pain from osteoarthritis and orthopedic surgery

Answer 34

Generic: robenacoxib COX-2 (no COX-1 at therapeutic dose) Newest NSAID: oral tabs and injectable Labelled for cats once a day up to 6 days Also available for dogs ($$$) Oral form must be given with food Injectable form has 3 days duration after single dose Same precautions and adverse effects as other NSAIDs May have slight less systemic effects as drug concentrates in inflamed tissues

Answer 35

Cattle: treatment of fever, pain and inflammation associated with a variety of conditions including: respiratory tract infections, mastitis, udder edema, downer cow syndrome, endotoxemia, simple gastrointestinal disorders, arthritis and traumatic musculoskeletal injuries.

Answer 36

Swine: recommended for the treatment of fever and inflammation associated with respiratory tract infections.

Answer 37

Dogs and Cats: for the alleviation of inflammation, lameness and pain due to osteoarthritis, hip dysplasia, disc disease, spondylosis, panosteitis, trauma, and related musculoskeletal diseases; for the management of post- surgical pain; for the symptomatic treatment of fever.

Answer 38

Horses: recommended for the alleviation of inflammation and pain associated with musculoskeletal disorders.

Answer 39

(Advil®, Motrin®) - Ibuprofen,(Aleve®) - Naproxen COX non-selectives Human OTC Often found in other medications (i.e., cough meds and muscle relaxants) Considered a toxin in vet med AVOID in vet species No WDT for food animals Can cause acute fatal liver failure in dogs, cats Severe GI ulceration Adverse effects can occur with single dose Acetaminophen Tylenol® Not an NSAID Mechanism unknown but reduces the perception of pain; Anti-pyretic, analgesic only Does NOT have anti-inflammatory activity Toxicity occurs at very low dose in cats (high dose in dogs). Single regular strength tablet can kill a cat Alters hemoglobin to methemoglobin (which does not carry oxygen) Also hepatotoxic

Answer 40

Histamine is released by mast cells and basophils; to lesser degree by platelets Release is triggered by: Acute tissue damage IgE binding to mast cells and basophils Histamine binds to H1-receptors Turns on acute inflammation pathway Causes vasodilation and edema Causes bronchoconstriction Histamine also binds to H2-receptors in GIT Turns on gastric acid production – will cover in GI section

Answer 41

Anti-histamine = “stops” histamine Binds to histamine-receptor and blocks histamine from binding Do not have any influence on receptors that are already bound by histamine Therefore, more effective at prevention than treatment of a histamine response “Rebound effect” seen in humans not commonly noted in animals

Answer 42

Major indications for antihistamines (H1 blockers): Preventing and treating inflammation due to allergy, atopy and asthma Blocks inflammation related to H1 receptor effects. Also has anti-pruritic effect Also has anti-anxiety effect that calms patient who is otherwise painful and itchy Anaphylaxis vaccine reactions Blocks inflammation cascade and blocks vasodilation Bronchodilation Prevents

Answer 43

Few minor side effects at therapeutic dose Transient drowsiness, mild sedation most common Anticholinergic effects such as dry mouth, mydriasis, urine retention At higher dose, can cause Vomit, diarrhea, nausea Overdose can cause hyper excitability, disorientation, seizures and even death

Answer 44

Trade name and generics available; names used interchangeably. Must know both! Main indications: #1 drug or emergency treatment of anaphylaxis; including vaccine reactions (in emergency drug kit) Can pre-treat patients at-risk for vaccine reactions Prevention/maintenance/treatment of allergy, atopy and asthma

Answer 45

Side effects are sedation and anticholinergic effects Routes: IV is over 90 sec or can cause anaphylaxis IM, SQ – allow 15 min for effect Oral for at home PRN and chronic maintenance

Answer 46

Prednisolone + trimeprazine (antihistamine) Commonly used in SA Very effective for both acute and chronic prevention and treatment of allergic dermatitis and atopy Anti-inflammatory, analgesic, prevents histamine activity, anti-anxiety, antipruritic Presence of trimeprazine decreases dose of steroid required

Answer 47

Adverse effects are mostly related to the prednisolone List 6 side effects of short or long term usage

Answer 48

Horses Contains: pyrilamine maleate (antihistamine) + ephedrine hydrochloride (bronchodilator)

Answer 49

These drugs TURN OFF the immune system Stop inflammation AND adaptive immunity Act by inhibiting lymphoyctes (T cells and B cells)

Answer 50

Preventing rejection of grafts/transplants Control autoimmune diseases (immune-mediate hemolytic anemia (IMHA), myasthenia gravis, pemphigus, perianal fistula, atopy, immune-mediated polyarthritis, systemic lupus erythematosus)

Answer 51

Adverse effects vary depending on the drug and patient Can range from vomit and diarrhea to acute liver failure and bone marrow suppression ALL drugs cause immunosuppression Increased risk of infection Increased risk of neoplasia May interfere with ability to respond to vaccines

Answer 52

High dose steroids At high dose, inhibit both T cells and B cells See notes on glucocorticoids for adverse side effects. High dose chronic use increases risk of GI ulcerations, hepatopathy and iatrogenic Cushing’s disease cyclosporine (Atopica®) azothiaprine (Imuran®) oclacitinib (Apoquel®) – for severe allergy in dogs