Immunosuppression Flashcards
Omalizumab
Monoclonal antibody against IgE, used to treat urticaria (exaggeration of triple response) and allergic asthma. Omalizumab is built on an IgG framework and so does not activate FcεRI itself.
Sodium cromoglycate
Reduces Ca2+ influx into mast cells by inhibiting a Cl- conductance that is usually needed to maintain a negative potential for Ca2+ influx.
Prevents degranulation, eye drops for hay fever/allergic rhinitis, also used for mastocytosis, asthma.
Not useful to treat RAO (asthma equivalent in horses) since neutrophils play a larger role than mast cells.
β2-adrenoceptor agonists + PDE inhibitors
Raising [cAMP] inhibits mast cell degranulation.
Mepyramine
1st generation H1 antagonists. Causes drowsiness. Used topically for insect bites
Terfenadine
2nd generation anti-histamine, inhibited Kv11.1/hERG causing long QT syndrome/torsades de points syndrome. Prodrug (with respect to its anti-histamine action) metabolised by CYP3A4 to fexofenadine.
Fexofenadine
3rd generation anti-histamine (non-drowsy), used to treat hay fever, allergy, urticaria
Loratadine
3rd generation anti-histamine (non-drowsy, no cardiac side-effects), used to treat hay fever, allergy, urticaria
Adrenaline
Used for anaphylaxis. Counteracts systemic vasodilation, increases cAMP to inhibit mast cell degranulation, relieves bronchospasm. Noradrenaline is not used as it’s such a strong vasoconstrictor that it causes reflex bradycardia.
Imatinib
Receptor tyrosine kinase inhibitor used to treatment mastocytosis (ineffective in people with common c-kit/D816V mutation).
Oclacitinib
JAK inhibitor, used to treat allergic dermatitis in dogs
Proglumide
CCK2 receptor antagonist. Inhibits histamine release from ECL cells.
Cimetidine
H2 receptor antagonist but inhibits CYP enzymes.
Ranitidine
H2 receptor antagonist.
Omeprazole
Proton pump inhibitor. Treats peptic ulcers.
Converted to their active form in the acidic environment of the parietal cell and form disulphide bonds with the K+/H+ pump.
Issues: Broken down by H+, have a slow onset to maximal effectiveness, predominantly metabolised by CYP2C19, which exhibits significant genetic polymorphism.
Vonoprazan
Potassium-competitive acid blocker (P-CAB). Treats peptic ulcers.
Competes with the K+ binding site, has greater stability than PPIs in H+, CYP2C19 is less vital in its metabolism
Gaviscon
Antacid that neutralises stomach pH
Misoprostol
PGE1 analogue. Treats peptic ulcers.
Action of PGE2 include:
(1) Acts on EP2/3 receptors on ECL cells to decrease histamine release.
(2) Acts on EP4 receptor to increase mucin release
(3) Acts on EP1/2 receptors to increase bicarbonate release.
Arthrotec
Diclofenac (a NSAID) + misoprostol. Misoprostol acts to prevent NSAID-induced ulceration.
Diclofenac
NSAID: Non-selective COX inhibitor, used in treating chronic inflammation. Used to lessen pain and inflammation in rheumatoid arthritis and lessen pain in osteoarthritis and SLE.
Icatibant
B2 receptor antagonist used in the treatment of HAE.
Tanezumab
Anti-NGF antibody, in clinical trials for pain relief for osteoarthritis.
Montelukast
CysLT1 receptor antagonist, use in treatment of asthma.
Ibuprofen
NSAID: Non-selective COX inhibitor, used as analgesic, antipyretic and anti-inflammatory.
Etoricoxib
COX-2 selective inhibitor, used for chronic inflammation in patients that don’t have a substantial cardiovascular risk.
All NSAIDs have following side effects: GI bleeding (COX-2 selective inhibitors show lower GI side effects), renal insufficiency, increased myocardial infarction risk (also with COX-2 selectives since COX-2 is constitutively expressed in coronary VSMCs), bronchospasm (mechanism unknown).
Aspirin
Irreversibly inhibits COX by acetylating Ser530, and turns into salicylate, a reversible COX inhibitor. Weakly COX-1 selective.
Used to reduce risk of platelet aggregation.
Irreversible means that low doses can be used to minimise side effects.
Acetylated COX-2 forms ATL (15R-epi-lipoxin A4) which has similar functions to LXA4 so aspirin is also an anti-inflammatory.
Reye’s syndrome: Hepatic encephalopathy that occurs in children.
Salicylism: Metabolic acidosis due to disrupted carbohydrate metabolism. Leads to respiratory depression and coma. Treatment: (1) administer fluids, (2) bicarbonate to enhance aspirin elimination, (3) activated charcoal to adsorb aspirin, (4) haemodialysis.
Don’t use in cats.
Paracetamol
Analgesic, anti-pyretic, poor anti-inflammatory. Weakly COX-2 selective, but COX-3 selective in canines. Acts by reduction of active site in COX enzymes required to produce PGH2 from PGG2.
Metabolised by glucuronidation, sulphonation, or CYP2E1. Sulphonation first to saturate, then glucuronidation. CYP2E1 converts paracetamol to NAPQI which causes hepatotoxicity and is detoxified by glutathione. Alcohol upregulates CYP2E1 and fasting decreases glutathione levels.
Don’t use in cats and dogs.
N-acetylcysteine
Increases hepatic glutathione production .
Phenylbutazone
NSAID used mainly in horses, many side effects in humans.
Robenacoxib
COX-2 selective inhibitor used in cats and dogs.
Firocoxib
COX-2 selective inhibitor used in dogs and horses.
Ondansetron
5-HT3 antagonist. Anti-emetic.
Cyclizine
H1 receptor antagonist. Anti-emetic.
Metoclopramide
D2 receptor antagonist. Anti-emetic. Can cause acute dystonia due to striatal D2 receptor inhibition.
Scopolamine
Non-selective muscarinic receptor antagonist, acts via M1 as an anti-emetic.
Sumatriptan
5-HT(1B/D/F) agonist used for migraine. 5-HT(1B) causes vasoconstriction and 5-HT(1D/F) inhibits nociceptor activity.
Vasoconstriction can be bad so sumatriptan is contraindicated in coronary disease.
Can’t be taken orally and doesn’t cross BBB.