Sympathetic NS Flashcards
What receptor does Phenylephrine act upon?
Alpha 1
List 4 SNS pure agonist drugs
Phenylephrine
Alpha methyldopa
Dopamine
Salbutamol
What receptor does Alpha methyldopa act upon?
Alpha 2
What receptor does Dopamine act upon?
Beta 1
What receptor does Salbutamol act upon?
Beta 2
List 4 SNS non-specific Agonist drugs
Ephedrine
Amphetamine
Cocaine
Adrenaline
List 4 SNS blockers
Doxazosin
Atenolol/bisoprolol
Propanolol
Carvedilol
Name which receptor Doxazosin act upon?
Alpha 1
What receptor does Atenolol/Bisoprolol act upon?
Beta 1
What receptor does Propanolol act upon?
Beta 1 and beta 2
What receptor does Carvedilol act upon?
Alpha 1, beta 1 and beta 2
Which drugs act upon alpha 1 receptors and what are their respective MOA?
Phenylephrine - SNS pure a1 agonist
Doxazosin - SNS a1 blocker
Carvedilol - SNS a1,b1,b2 blocker
Which drugs act upon alpha 2 receptors and what are their respective MOA?
Alpha methyldopa - SNS pure a2 agonist
Which drugs act upon beta 2 receptors and what are their respective MOA?
Dopamine - SNS pure b1 agonist
Atenolol/Bisoprolol - SNS b1 blocker
Propanolol - SNS b1,b2 blocker
Carvedilol - SNS a1,b1,b2 blocker
What are the therapeutic effects of Phenylephrine and what it is used to treat?
Vasoconstriction
Increases blood pressure
Maybe mydriasis
- Topical to nose
- conjunctivitis
- allergy rhinitis
- flu (decongestant)
What are the therapeutic effects of Alpha Methyldopa and what it is used to treat?
Decreases TPR
- Twice daily. Liver metabolism.
- Hypertension
- Hypertension due to pregnancy!
What are the therapeutic effects of Dopamine and what it is used to treat?
Increases CO (increases conductivity of SA node and increases contractility) Increases renal perfusion
- IV use.
Cardiogenic shock (increase CO and HR)
What are the therapeutic effects of Salbutamol and what it is used to treat?
Bronchodilation in airways
Stops uterine contractions
Asthma and COPD
Premature labour
What are the therapeutic effects of ephedrine and what it is used to treat?
Vasoconstriction
Increase CO
Increase HR
Increase vessel resistance
- Weaker than amphetamine
- Doesn’t cross blood-brain barrier easily
Oral congestion (oral decongestant)
What is the MOA of phenylephrine?
Mimics the effects of NA and Adren. on a1 receptors in vascular smooth muscle
Increases blood pressure by vasoconstriction (can be used locally to do so)
What is the MOA of alpha methyldopa?
Decreases presynaptic release of Na in the vasomotor centre of the brain thus increasing SNS effects Decreases TPR (total peripheral resistance) but leaves other reflexes intact.
What is the MOA of dopamine?
Mimics effects of neurotransmitters on b1 in heart and JG cells of kidney
Increases levels of cAMP
Increases O2 demand in heart
Increases conduction through the SA node
What is the MOA of salbutamol?
Mimics action of adrenaline on b2 receptors in lungs, blood vessels, pregnant uterus and liver
Increases relaxation of smooth muscle (by increasing cAMP levels)
What is the MOA of ephedrine?
Mimics the effects of NA and Adren. on the b1 receptors in the heart and JG cells.
Increases SNS by increasing synaptic neurotransmitters
Released presynaptically by NA
What are the therapeutic effects of amphetamine and what it is used to treat?
Increases SNS effects
- Addictive (drug of abuse)
What is the MOA of amphetamine?
Mimics the effects of NA and Adren. on the b1 receptors in the heart and JG cells.
Increases SNS by increasing synaptic neurotransmitters (it is released presynaptically by NA)
Stimulates NA in the brain which increases dopamine levels there (addiction)
What are the therapeutic effects of cocaine and what it is used to treat?
Increases SNS effects
- Addictive (drug of abuse)
What is the MOA of cocaine?
Mimics the effects of NA and Adren. on the b1 receptors in the heart and JG cells.
Increases SNS by increasing synaptic neurotransmitters as it is a re-uptake inhibitor
Stimulates NA in the brain which increases dopamine levels there (addiction)
What is the MOA of doxazosin?
Blocks the binding of NA to the peripheral a1 adrenergic receptors
Competitive antagonist
Blocks SNS reflex after postural changes
What is the MOA of atenolol/bisoprolol?
Blocks the effects of NA and Adren. on b1 receptors
Pure antagonist
Blocks b-cells in brain
Increases renin release in JG cells
Blocks conduction through AV node and SA node
Decreases contractility and O2 demand in heart
- Cardioselective
- Loses b1 selectivity at higher doses (starts blocking b2)
What is the MOA of propanolol?
Blocks the effect of Na and Adren. on b1 and b2 receptors.
Pure antagonist in organs
Increases renin release in JG cells
Blocks b-cells in brain
Blocks conduction through AV node and SA node
Decreases contractility and O2 demand in heart
What is the MOA of carvedilol?
Blocks the effect of NA and Adren. on b1, b2 and a1 receptors
Pure Antagonist
Blocks conduction through the AV node and SA node
Blocks action of NA on vascular smooth muscle
What are the therapeutic effects of doxazosin and what it is used to treat?
Decreases TPR (by decreasing SNS) First dose hypotension (orthostatic or normal)
- Once daily
- Third line drug
Hypertension
BPH
What are the therapeutic effects of propanolol and what it is used to treat?
Decreases HR
Decreases SV
Decreases O2 consumption
Decreases conduction
- Short half-life (3-4 times daily)
Hypentension
Angina Pectoris
Supraventricular arrhythmia
What are the therapeutic effects of atenolol/bisoprolol and what it is used to treat?
Decreases HR
Decreases SV
Decreases O2 consumption
Decreases conduction
- Long half-life (1-2 times daily)
Hypentension
Angina Pectoris
Supraventricular arrhythmia
What are the therapeutic effects of carvedilol and what it is used to treat?
Stops catecholamine SNS, induces remodelling
Decreases conduction
- Must be built up in order to be used for prevent intolerance
Hypertension (in heart failure)
List any adverse effects or contra-indications of phenylephrine?
Hypertension
List any adverse effects or contra-indications of alpha methyldopa?
Depression
Tiredness (decreased NA in brain)
List any adverse effects or contra-indications of dopamine?
Anxiety (tremor)
Arrhythmia
Heart Failure
List any adverse effects or contra-indications of salbutamol?
Anxiety (tremor)
Palpitations
Tachycardia (activation of b1 receptors)
List any adverse effects or contra-indications of ephedrine?
Anxiety (tremor)
Arrhythmia
Heart failure
List any adverse effects or contra-indications of amphetamine?
Anxiety (tremor)
Arrhythmia
Heart failure
List any adverse effects or contra-indications of cocaine?
Anxiety (tremor)
Arrhythmia
Heart failure
List any adverse effects or contra-indications of adrenalin?
Anxiety (tremor)
Arrhythmia
Heart failure
What are the therapeutic effects of adrenaline and what it is used to treat?
Increases CO Increases HR Increases contractility (and conduction) Incraeses O2 demand in heart Bronchodilation (lungs) Increases blood flow in skeletal blood vessels
- Only IV or SC (sub-cutaneous)
Cardiogenic shock
Anaphylaxis
What is the MOA of adrenaline?
mimics effect of NA on b1 adreno-receptors in heart and JG cells
Increases conduction through AV node and SA node
Increases contractility and O2 demand in heart
List any adverse effects or contra-indications of doxazosin?
Depression
Tiredness (blockade of a1 receptors in brain)
Orthostatic hypotension
List any adverse effects or contra-indications of atenolol/bisporolol?
Diabetes Heart block Heart failure COPD (chronic obstructive pulmonary disease) Asthma PVD (peripheral vascular disease)
List any adverse effects or contra-indications of propanolol?
Diabetes Heart block Heart failure COPD (chronic obstructive pulmonary disease) Asthma PVD (peripheral vascular disease)
List any adverse effects or contra-indications of carvedilol?
Diabetes Heart block COPD (chronic obstructive pulmonary disease) Asthma PVD (peripheral vascular disease)
