Pharmacology of Analgesic Agents II: NSAIDs & NSAID-like Drugs Flashcards
What pKa is expected of an NSAID?
3-5 (weak acid)
NSAIDs are considered highly…
protein bound
What are the main routes of administration of NSAIDs?
IV, SQ, PO, IM
NSAIDs are metabolised in the
liver, go through enterohepatic circulation
NSAIDs are excreted by the
kidney
What are the main effects of NSAIDs?
- anti-inflammatory (local)
- analgesia (local & systemic)
- antipyretic
- antiendotoxic
- anti-thrombotic
- antispasmodic
What are adverse effects of NSAIDs?
GIT & kidney mostly
What are GIT adverse effects from NSAIDs?
- V/D
- melena
- ulcers
- anorexia
- STOP ADMIN IMMEDIATELY
What are renal adverse effects of NSAIDs?
Vasoconstriction (afferent/efferent blood vessels) –> glomerular dysfxn –> renal failure
What are the two different ways of classifying NSAIDs?
- Physiochemical properties (carboxylic acids, enolic acids, coxibs)
- according to action on COX (non-selective, COX-2 selective, COX-2 specific, Dual inhibitors)
Phenylbutazone
Give routes, classification, animals used in, cautions
- Classification: Non-selective COX inhibitor (COX-1 activity)
- Routes: PO, IV
- Animals: horses, dogs w/ caution
- Illegal in animals for human consumption
- Caution: hepatotoxicity in dogs
Flunixin meglumine
Give routes, classification, animals used in, cautions
- Classification: Non-selective COX inhibitor (COX-1)
- Routes: PO, IV, some in IM prep
- Animals: Horses, large animals
- Caution: severe renal effects in dogs
Meloxicam
Give routes, classification, animals used in, cautions
- Classification: COX-2 selective
- Routes: PO, SQ, IV
- Animals: dogs, cats, horses, cattle
- Cautions: less side effects
Carprofen
Give routes, classification, animals used in, cautions
- Classification: COX-2 selective
- Routes: PO, IV, IM, SQ
- Animals: dogs, cats, cattle
- Caution: idiosyncratic liver failure in dogs (Golden retrievers), dogs love to eat the chews –> easy to overdose if eat the bottle
Robenacoxib (Onsior)
Give routes, classification, animals used in, cautions
- Classification: Highly COX-2 selective
- Routes: PO, SQ
- Animals: dogs, cats
- Cautions: CAUTION in hyperproteinaemia
Ketoprofen
Give routes, classification, animals used in, cautions
- Classification: Non-selective COX inhibitor (COX-1)
- Routes: PO, Injection
- Animals: Pigs
- Cautions: not licensed in perioperative period
Firocoxib (Previcox)
Give routes, classification, animals used in, cautions
- Classification: COX-2 selective
- Routes: oral, others?s
- Animals: horses, dogs
- Cautions: Not licensed in perioperative period
Cimicoxib (Cimalgex)
Give routes, classification, animals used in, cautions
- Classification: ?
- Routes: ?
- Animals: Dogs
- Cautions: not licensed in perioperative period
Paracetamol
Give routes, classification, use, animals used in, cautions
- Routes: PO, IV
- MOA: inhibition of COX-3, weak COX-1/2 inhibition, endocannabinoid, vallinoid
- Use: Analgesia, antipyretic
- Animals: NOT IN CATS
- Cautions: saturation of gluronide pathway, production of NAPQI, inadeq glutathione availability –> Toxicity (cell & protein damage, methaemoglobinaemia, hepatic necrosis)
Grapiprant (Galliprant)
Give routes, classification, use, animals used in, cautions
- Classification: Non-COX-inhibiting PGE2EP4 receptor antagonist
- Route: Oral, others?
- Use: OA in dogs
- Animals: Dogs
- Cautions: V in the beginning of txt
Gabapentin
Give routes, classification, use, animals used in, cautions
- Route: Oral
- Classification: Structural analogue of GABA, does not act on GABA
- MOA: blocks Ca2+-gated channels on neurons, possible NMDA antagonism, opioid antagonist, Na+ or monoaminergic pathways
- Use: neuropathic pain
- Animals: dogs/cats (birds - Plumbs)
- Cautions: Assoc’d w/ foetal loss & teratogenic effects in lab settings
Pregabalin
Use: neuropathic pain in dogs
Like gabapentin but $$$
Amitriptyline
Give routes, classification, use, animals used in, cautions
- Routes: oral only
- Classification: tricyclic antidepressant
- Use: behavioural disorders, FLUTD, neuropathic pain
- Animals:
- Cautions: tachycardia, fatal V-tach, hypersalivation, V, weight gain, sedation, serotonin syndrome
Ketamine
Give routes, classification, use, animals used in, cautions
- Route: ?
- Classification: Dissociative anaesthetic agent, NMDA-receptor antagonist
- Use: Anaesthetic agent, chronic pain mgmt
- Animals: ?
- Cautions: CV depression in shock/moribund animals
Amantadine
Give routes, classification, use, animals used in, cautions
- Route: Local, oral
- Classification: Dopamine agonist, NMDA antagonist
- Use: chronic pain, arthritis, neuropathic pain
- Animals: ?
- Caution: serotonin syndrome, CNS stimulation
Memantine
Give routes, classification, use, animals used in, cautions
- Route: Liquid, tablets
- Classification: Non-competitive inhibitor of NMDA receptor
- Use: chronic pain, arthritis, neuropathic pain? Alzheimer’s txt, Canine cognitive dysfunction txt
- Animals: ?
- Cautions: possible abuse potential
What is serotonin syndrome?
Variety of clinical signs caused by excessive serotonin in the body
What are clinical signs of serotonin syndrome?
- V/D
- changes in conscious state (anxious, restless)
- autonomic dysfxn (hypertension, tachycardia, hyperthermia)
- neuromuscular signs (muscle rigidity & tremors, seizures)
How do you treat serotonin syndrome?
- discontinuarion of drugs
- gastric lavage
- supportive care
