Types of Drugs Flashcards
mimics the response of ACh
cholinergic agonist
- longer duration of action
- prefer to bind directly to muscarinic -receptors
- show little specificity in their actions
- synthetic esters of choline
- mimics the response of ACh
direct acting cholinergic agonist
- inhibit AChE which prolongs the lifetime of ACh
- results in an accumulation of ACh
- acts on muscarinic and nicotinic receptors
indirect acting cholinergic agonist - reversible
- organophosphates bind with AChE
- results in long lasting ACh at all sites
indirect acting cholinergic agonist - irreversible
- reactivates previously inhibited AChE
- produces aging of enzyme complex
reactivation of AChE inhibitors
- cholinergic blockers
- bind to cholinoceptors to block the normal response
- work against ACh
cholinergic antagonist
- block parasympathetic innervation
- sympathetic innervation left unopposed (do not block nicotinic receptors)
- have little to no effect at skeletal NMJ or autonomic ganglia
- number of antihistamine and antidepressants have this type of activity
antimuscarinic agents or muscarinic blockers
- act on nicotinic receptors of both SNS and PSNS
- not as effective as NMJ antagonists
- blocks the entire output of ANS at the nicotinic receptor
- non depolarizing response = complex and unpredictable
ganglionic blockers
-block cholinergic transmission between motor nerve endings and nicotinic receptors on the neuromuscular end plate of skeletal muscle
neuromuscular blockers
- neuromuscular blocker
- competitive
- acts as an antagonist to ACh
non depolarizing neuromuscular blocker
- neuromuscular blocker
- acts as an agonist to ACh
depolarizing neuromuscular blocker
- can act directly on the adrenergic receptor by activating it; called sympathomimetic
- agents either directly or indirectly stimulate the adrenoceptors
adrenergic agonists
- directly stimulate adrenoceptors
- producing effects similar to those that occur following the stimulation of sympathetic nerves or the release of epinephrine
- activated receptors initiate synthesis of a second messenger and subsequent intracellular signals.
direct acting adrenergic agonist
- indirectly stimulate adrenoceptors
- by blocking the uptake of norepinephrine or are taken up into the presynaptic neuron which causes a release of norepinephrine from the adrenergic neuron
- do not directly affect postsynaptic receptors.
indirect acting adrenergic agonist
-induce the release of norepinephrine from presynaptic terminals and they activate adrenergic receptors on the postsynaptic membrane
direct and indirect acting adrenergic agonists
- affect the receptors that are stimulated by norepinephrine and epinephrine
- block the action of the NT’s at the receptors by binding to the adrenoceptors but do not trigger the usual intracellular effects
- can act reversibly or irreversibly attaching to the receptor preventing its action by endogenous catecholamine’s
- antagonists that block dopamine receptors are most important in the CNS
adrenergic antagonists
- profoundly affect BP
- blocking these receptors reduces the sympathetic tone of the blood vessels, resulting in decreased peripheral vascular resistance which induces a reflex tachycardia resulting from the lowered BP
adrenergic antagonists - alpha blockers
- all competitive antagonists
- can be either nonselective or selective
- non selective block B1 and B2 whereas cardio selective antagonists block B1
- all lower BP and do not induce postural hypotension (b/c A remain functional)
adrenergic antagonists - beta blockers
effective in treating: angina, cardiac arrhythmias, myocardial infarction, congestive heart failure, hyperthyroidism, glaucoma and serving in prophylaxis of migraine headaches.
adrenergic antagonists - beta blockers
- exert their effects indirectly on the adrenergic neuron by blockade reuptake of NT into the cytoplasm or by causing the release of NT from storage vesicles or act on the adrenergic neuron wither to interfere w/NT release or to alter the uptake of the NT into the adrenergic nerve
- *rarely used therapeutically
adrenergic antagonists - drugs affecting neurotransmitter uptake/release
