Autacoids Flashcards
________ are chemical mediators that are synthesized and fusion in a localized tissue or area, and participate in the physiologic or pathophysiologic response to injury
Autacoids
What are the groups of allergy drugs?
Antihistamines (H1)
Leukotiriene inhibitors
Janus kinase inhibitors
What two groups to the behavior modifying drugs fall into ?
Serotonin (5-HT) altering
Tricyclic antidepressants
Histamine is synthesized form?
Dietary histidine
Where is histamine stored int he body ?
Tissue - lung, skin, stomach
Cellular - mast cells and basophils
What are triggers for histamine release?
Immune-mediated (degraulation of mast cells/basophils)
Drug-induced (hypersensitivity )
Plant/animal stings
Physical injury (disrupt mast cells)
What are the histamine receptors
Type 1- Gq coupled
Type 2- Gs coupled
Type 3- presynaptic neuron
Type 4 - inflammatory cells
What type of reaction are type 1 histamine receptors involved in?
Gq coupled -> Ca and protein kinase C
Contraction of smooth muscle
Increase bronchial secretion
Inflammation
Relax vascular smooth muscle
Increase capillary permeability
Pruritus
What type of reaction are type 2 histamine receptors involved in?
Gas-coupled -> adenylyl cyclase -> increase cAMP
Relaxation of vascular smooth muscle and increased gastric acid secretion
What are targets for antihistamine drugs?
Prevent release from mast cells
- glucocorticoids
- chromolyn sodium
Histamine antagonist
-catecholamines physiologically antagonize effects
Block histamine receptors
Type 1 receptor antagonist will have what effects?
Relax bronchiolar and intestinal smooth muscle
Inhibit vasodilation by histamine
Inhibit pruritus (local anesthesia and reduce sensation)
What is a common side effect, especially by 1st generation, antihistamines?
Sedation
How are Type 1 receptor antagonists administered and metabolized?
Orally - well distributed
Metabolized by P450
How are type 1 receptor antagonists excreted?
First gen -> kidney
Second gen -> feces
What are the adverse effects of type 1 receptor antagonists?
CNS depression Antimuscarinic signs (dry mouth and increased IOP)
Drug tolerance
Rarely hypersensitivity
What are the first gen type 1 receptor antagonists?
Diphenhydramine
Hydroxyzine
Trimeprazine
Ketotifen -ophthalmic
What are the second gen type 1 receptor antagonists?
Loratadine (human, little info in vet patients)
Most well tolerated
What is the primary use of type 2 receptor antagonists?
Treat/prevent gastric ulcers and gastritis associated with hyperacidity
What are the H2 receptor antagonists?
Cimetidine, famotidine, and ranitidine
How do Janus-kinase inhibitors have an anti-pruritic effect ?
JAK 1 and JAK 3
Inhibits pro-inflammatory cytokines
Inhibit IL31-> neuronal sensation of itching
What are adverse effects of oclacitinib?
GI signs
Polydipsia
Lethargy
Oclacitinib is a _____________ used to reduce pruritus
Janus kinase inhibitor
Leukotriene inhibitors reduce pruritus by? What drug is in this group?
Inhibiting IL31
Zafirlukast
What are the 4 drugs used to treat behavioural issues that we discussed?
Clomipramine
Fluoxetine
Trazodone
Doxepin
Benzodiazepines work on the _______ receptor and have what behaviour modifying effect?
A2
Anxiolytics
Adjunct therapy if issue is associated with anxiety
What is the major side effect to benzodiazepine when used as an anxiolytics?
Sedation
How doe TCA’s modify behaviour
Tricyclics antidepressant
-> increase neurotransmitter level (serotonin and norepi) by preventing reuptake
What type of drug is clomipramine?
Tricyclics antidepressant
Cloipramien should not be used with ??
MAO inhibitors (selegiline) Aged cheeses (tyramine)
When is clomipramine contraindicated?
When anticholinergics are contraindicated
Glaucoma
Decreased GI motility
Arrhythmia
How does a SSRI modify behaviour?
Selective serotonin-reuptake inhibitor
Prevent re-uptake of serotonin by the presynaptic neuron -> increase duration (increased level of serotonin)
Fluoxetine is what type of drug?
Selective serotonin-reuptake inhibitor
How is fluoxetine administered?
Orally
Transdermal in cat (compounded)
What are adverse effects to using fluoxetine?
Seizure
Lethargy
Anorexia
Aggression
What do I use to treat separation anxiety in canines?
Fluoxetine
What type of drug is trazodone?
Serotonin 2A Antagonist/Reuptake inhibitor (SARI)
What is the MOA of trazodone?
Antagonized a1 -> reduced BP
Augment effect of SSRI-> increased serotonin -> decreased anxiety
I should not give Trazodone to patients receiving ________
MAO I (selegiline)
What are adverse effects of trazodone?
Sedation Ataxia Priapism Cardiac conduction disturbance Anxiety Aggression
What can I use to treat noise phobia in my dog?
Trazodone -> potentiate serotonin in CNS -> decrease anxiety
What type of drug is Doxepin?
TCA/Antihistamine (H1)
What is the MOA of Doxepin?
Inhibit norepi and serotonin reuptake (antidepressant)
Why may I choose Doxepin over clomipramine?
Clomipramine has noradrengeric and anticholinergics activity -> more cardiovascular effects
Doxepin moderately inhibits norepi and serotonin -> less potential for cardiovascular effects
What behavior modifying drugs has been used to treat allergic dermatitis in canines?
Doxepin
Antihistamine effect or CNS effect ?
What type of drug would I use to reduce urticaria, pruritus, or reduce the effect of anaphylaxis ?
Type 1 receptor antagonist
Dipehyhydramine
Hydroxyzine
Trimeprazine
Loratadine
