Lecture 2: Respiratory Drugs and Treatments for Allergy Flashcards
What are some indications for antihistamines/H1 antagonists
Sedation, prophylaxis of atopic dermatitis, aseptic laminitis (cows), blood transfusions, tx MCT, motion sickness
What are some first generation H1 antagonists
- Diphehydramine HCl
- Chloropheniramine maleate
- Promethazine HCl
- Trimeprazine tartrate
- Hydroxyzine HCl
What is the second generation H1 antagonist
Cetirizine
How do H1 antagonist affect neurotransmission
Histamine is typically stimulatory so antagonist will block that excitatory effect- promotes sedation
What are H1 antagonists role in anaphylaxis
Histamine typically causes vasodilation and reflex tachycardia in anaphylaxis, but H1 antagonist will block vasodilation so promote constriction and increase BP
What is the mechanism in which histamine causes vasodilation
- Histamine binds to H1 receptor
- Activates NO synthase
- NO acts on guanylyl Cyclase turning GTP to cGMP
- Inhibits PLC
- Promotes vascular smooth muscle relaxation
Which has a lower VD- first or second generation h1 antagonists
2nd generation- cetirizine
If you have a patient who needs to treat an allergy but doesn’t want to have sedative effect which drug should you put on and why
Ceterizine- second generation h1 antagonist that has lower VD- does not cross BBB so no sedative effect
What are some adverse effects of h1 antagonists
Sedation, paradoxical excitation, anticholinergic effects, iatrogenic Cushing with temparil P
Which h1 antagonist contains prednisolone
Temparil P
Which generation of h1 antagonists cause anticholinergic effects
First generation
What is oclacitinib labeled for
Treatment of pruritic atopic dermatitis
What is the mechanism of action for oclacitinib
Competitive inhibitor of JAK1/JAK3–> inhibits signaling in target cells due to inflammatory cytokines
What is the mechanism of action of lokivetmab
Caninized monoclonal antibody to IL-31, so can’t activate JAK1/2 pathways, reduces the perception of itch
What are some adverse effects of lokivetmab
Erythema, anorexia
What is cyclosporine A indicated for
Labeled: atopic dermatitis in dogs and cats
ELDU: keratoconjunctivitis sicca and autoimmune disorders
What is the mechanism of action of cyclosporine A
Blocks calcineurin so can’t form NFAT which promotes production of IL-2