M2 L2: sympathetic NS Flashcards
sympathomimetic agents
= adrenergic drugs
- stim SNS
sympatholytic agents
= antiadrenergic drugs
- inhibit SNS
classes of sympathomimetic agents
direct-acting: bind to receptors and elicit a response (ex: epinephrine). they mimic the effect of epinephrine.
indirect-acting: increase release of NE from presynaptic neuron (ex: amphetamines). same effect in a diff mechanism, stim the release of the natural transmitters (epinephrine and norepinephrine).
mixed: both direct and indirect effect (ex: ephedrine). mix between both some effect on receptors, some can stimulate.
albuterol
more important beta-2 for treating asthma
therapeutic indications: anaphylaxis
α and β agonists
- severe allergies; penicillin, peanuts, shellfish, etc.
- Epi pens are full of epinephrine - save lives but also monitor after
- Epinephrine: acts on both alpha and beta receptors
therapeutic indications: heart
β1 agonists
- complete heart block - cardiac arrest
- cardiogenic shock
- ex: dobutamine
therapeutic indications: asthma
β2 agonists
therapeutic indications: nasal congestion
α1 agonists
- decongestants ex: pseudoephedrine
disadvantage: rebound congestion
therapeutic indications: pupil dilation
α1 agonists
- for fundas examination
alpha agonists
constricts the blood vessels - nasal congestion the nose is dilated and engorged with blood so this would reduce nasal congestion, can also be used in pupil dilation
anaphylaxis
- severe hypersensitivity reaction to certain types of food, drugs, bee sting, etc
- affect resp and cardio sys: severe bronchospasm, mucous membrane congestion, severe hypotension -> shock
treatment: EPINEPHRINE
- activates α & β receptors -> bronchodilation
- vasoconstriction of blood vessels -> restores bp
- increased heart rate and myocardial contraction
adverse effects anaphylaxis
CNS: headache, restlessness, tremors, dizziness, anxiety, insomnia
CVS: dysrhythmia and palpitation, vasoconstriction -> hypertension and myocardial ischemia
- anorexia, nausea, vomiting
- dry mouth
- muscle cramps
classes of sympatholytic agents
α receptor antagonists: non-selective, α1 blockers, α2 blockers
β receptor antagonists: non-selective, β1 blockers, β2 blockers
α and β receptors antagonists
- Alpha receptors: will block a1 or a2
- A1 - helpful in hypertension
- B-2 blockers don’t have a ton of use, mostly on b1’s
- B1 blockers are IMPORTANT
- Beta 1 blockers for the treatment of hypertension and the heart, beta 2 agonist treatment for asthma (both very clinically relevant)
therapeutic indications for CVS: hypertension
- β blockers especially selective β1 blockers (cardioselective)
- α1 blockers - not preferred due to adverse effects
- α and β blockers - during pregnancy
Beta 1 main - cardio selective and cardioprotective
Beta receptors on heart rate - increase the heart rate, increase cardiac output
If you block beta receptors - becomes slow
therapeutic indications for CVS: angina and congestive heart failure
selective β1 blockers
therapeutic indications for CVS: dysrhythmias
selective β1 blockers
extrasystoles and tachyarrhythmias ex: SVT
impaired peripheral circulation (Raynaud’s disease)
α1 blockers
makes your blood circulation to extremities low, and makes your feet and hands cold. This can lead to extremities becoming pale. Alpha 1 blocks help here to dilate blood vessels.
therapeutic indications for CVS: pheochromocytoma
- adrenal medulla tumor -> increased secretion of E and NE
- manifestations:
CVS: hypertension, tachycardia, palpations
CNS: headache, anxiety, tremors
sweating
hyperglycemia - treatment:
1st choice treatment is surgery
α and β blockers can be used temporarily b4 surgery
makes epinephrine and norepinephrine and sends them to the blood, this leads to too much effect of the system. Can cause severe tachycardia, severe increased blood pressure, malignant hypertension, can lead to rupture of blood vessels, as well as heart attack (can be detrimental), also can lead to stroke if its blood vessels to the brain. Worst part is cardiovascular effect. Give them alpha and beta blocks, you need to block the effects of the system.
therapeutic indications for CVS: benign prostatic hyperplasia (BPH)
α1 blockers
relax smooth muscle in prostate and bladder - facilitate urination
A1 are useful for blood vessels, and benign prostatic hyperplasia
therapeutic indications for CVS: glaucoma
β blockers: non-selective or selective β1 blockers
Beta blockers or alpha agonists can be used to treat glaucoma
Add beta blockers to reduce heart rate if you want
therapeutic indications for CVS: neurological disorders
β blockers
migraine, anxiety, Parkinson’s disease (reduce tremors)
Beta blockers or alpha agonists can be used to treat glaucoma
Add beta blockers to reduce heart rate if you want
adverse effects - α1 blockers
- orthostatic hypotension
- 1st dose effect - hypotension
- nasal congestion
- headache, dizziness, weakness, fatigue
Take meds before bed, or take something else
Can happen especially with the first dose (Be in bed when it is taken)
They are a decongestant
adverse effects - β blockers
- bronchoconstriction
- CVS: bradycardia and AV-block, hypotension, exacerbation of heart failure, cold extremities
- CNS: depression and nightmares, hallucination, paresthesia
Mask the effect of hypoglycemia
what drugs have similar but not identical effects (2 groups)
- sympathomimetic and parasympatholytic drugs - both produce fight or flight response
- sympatholytic and parasympathomimetic drugs - both produce rest and digest response
