Drugs affecting Autonomous Nervous System Flashcards
Unit 2 ( adrenergic and adrenergic blocking drugs)
Explain nervous system
NErvous system consists of CNS and PNS. CNS is mainly the brain and the spinal cord where as PNS consists of autonomic nervous system which is involuntary and somatic nervous system which is voluntary. So autonomic nervous system consists of sympathetic nervous system which is fight or flight response and parasympathetic which is rest or digest response. Sympathetic is adrenergic and parasympathetic is cholinergic
What does sympathetic nervous system do?
Dilates the pupils
Dilates the bronchioles
increases the heart rate
constricts blood vessels
Relaxes bladder
relaxes smooth muscles
What is the neurotransmitter that of the sympathetic nervous system
Norepinephrine
Drugs that mimics sympathetic nervous system are
Sympathomimetic, adrenergic drugs or adrenomimetics
Drugs that blocks adrenergic drugs are
Sympatholytics, adrenergic blockers, adrenolytics
What is adrenergic agonist
Drugs that initiate a response
What is adrenergic anatgonist
Drugs that prevent a respone
What are the adrenergic receptors?
Alpha: Alpha 1 and 2
(A1: present in blood vessels, pregnant women, kidney liver, male sexual organs and causes vasoconstriction, decreased renin secretion and uterine contraction)
(A2: inhibits the release of norepinephrine)
Beta: B1, B2, B3
Dopamine- Subsets D1-5
How each receptors function?
Alpha receptors are excitatory everywhere except the guts
Beta receptors are inhibitory everywhere except the heart
Adrenergic receptors cell and their functions
A1: muscle contraction and vasoconstriction which will increase blood return in the heart and also increase the BP
A2: increase glucagon secretion and decrease insulin secretion (hence there will be more sugar present in the body)
B1: Increase heart rate and force of contraction
B2: muscle relaxation and vasodilation
B3: Lipolysis
dopaminergic: Can only be activated by dopamine. Dilate blood vessels and increase in blood flow
What is sympathomimetic drugs?
Drugs that mimics or facilitate some or all the actions of the sympathetic nervous system
What is the direct acting alpha 1 adrenergic agonist
Phenylephrine
Oxymetazoline
Indications of direct acting alpha 1 adrenergic agonists
Nasal decongestant, mydriatic and systemically as a vasopressor for hypertension to raise BP
What are the adverse effects of direct acting alpha 1 adrenergic drugs
Hypertension, nervousness, headaches
What are the indications for the diresct acting alpha 2 adrenergic agonist
Hypertension: produces inhibition of sympathetic vasomotor which reduces BP
ADHD and impulsive behaviour
Glaucoma
