Pharm random facts Flashcards
What is an example of a noncompetitive antagonist?
Phenoxybenzamine on alpha-receptors
What is an example of a competitive antagonist?
Flumazenil on GABA receptor
What is an example of a partial agonist?
Buprenorhine at opioid mu-receptors
How do you calculate the therapeutic index?
TD50/ED50 (median toxic dose/median effective dose)
alpha-1
Gq, increases vascular smooth muscle contraction, increased pupillary dilator muscle contraction (mydriasis), increased intestinal and bladder sphincter muscle contraction
alpha-2
Gi, decreased sympathetic outflow, decreased insulin response, decreased lipolysis, increased platelet aggregation, decreased aqueous humor production
beta-1
Gs, increased HR, increased contractility, increased renin release, increased lipolysis
beta-2
Gs, vasodilation, bronchodilation, increased lipolysis, increased insulin release, decreased uterine tone (tocolysis), ciliary muscle relaxation, increased aqueous humor production
M1
Gq, CNS, enteric nervous system
M2
Gi, decreased heart rate and contractility of atria
M3
Gq, increased exocrine gland secretions, increased gut peristalsis, increased bladder contraction, bronchoconstriction, increased pupillary sphincter muscle contraction, ciliary muscle contraction
D1
Gs, relaxes renal vascular smooth muscle
D2
Gi, modulates transmitter release, especially in brain
H1
Gq, increased nasal and bronchial mucus production, increased vascular permeability, contraction of bronchioles, pruritis, pain
H2
Gs, increased gastric acid secretion
V1
Gq, increased smooth muscle contraction
V2
Gs, increased H2O permeability and reabsorption in collecting tubules of kidney
Which receptor works through Phospholipase C?
Gq (H1, alpha-1, V1, M1, M3)
Which receptors work through Adenylyl cyclase
Gs activates it (beta-1, beta-2, D1, H2, V2). Gi inhibits it (M2, alpha-2, D2)
How does Gq work?
Receptor activates phospholipase C, which cleaves PIP2 into DAG and IP3. DAG activates Protein kinase C. IP3 increases the intracellular calcium which causes smooth muscle contraction and also activates PKC
How does Gs work?
Receptor activates adenylyl cyclase, which increases cAMP, which activates protein kinase A, which increases calcium (in the heart) and inhibits myosin light-chain kinase (in smooth muscle)
What should you think of if you see temperature dysasthesia?
Ciguatoxin (from reel fish, eg. barracuda, snapper, moray eel). Works by opening Na channels causing depolarization.
