Autonomic Drugs Flashcards
(43 cards)
Epinephrine
Drug class? Action? Causes? Clinical uses? Other?
Drug class: Direct sympathomimetic
Action: Beta agonist even at low doses, Alpha agonist at high doses (effect is Beta more than Alpha)
Causes: Vasoconstriction, increased heart rate and contractility, bronchodilation
Clinical uses: Cardiac arrest, hypotension, bronchospasm, anaphylaxis, open-angle glaucoma
More potent than Norepinephrine
Norepinephrine
Drug class?
Action?
Causes?
Clinical uses?
Drug class: Direct sympathomimetic
Action: Agonist of Alpha 1 > Alpha 2 > Beta 1 receptors (with Alpha 1 receptors being the primary site of action and Beta 1 the least).
Causes: Vasoconstriction which can lead to a reflex bradycardia
Clinical uses: Severe hypotension and shock
Isoproterenol
Drug class? Action? Causes? Clinical uses? Side effects?
Drug class: Direct sympathomimetic
Action: Agonist of Beta 1 = Beta 2 (same affinity for each beta receptor)
Causes: Vasodilation (from Beta 2 activation) leading to decreased BP, then there is a concurrent increase in heart rate and contractility secondary to reflex from decreased BP (reflex tachycardia) and the Beta 1 activation. Also causes some bronchodilation.
Isoproterenol
Clinical uses?
Side effects?
Clinical uses: Treats Torsades de pointes with Mg2+, occasionally used to treat complete heart block or cardiac arrest.
Side effects: Can worsen ischemia
Dopamine
Drug class?
Action?
Causes?
Clinical uses?
Drug class: Direct sympathomimetic
Action: Agonist of D1 = D2 > Beta > Alpha.
Causes: Increased renal perfusion, increased heart rate and contractility
Clinical uses: Severe hypotension, unstable bradycardia, heart failure, shock
Dobutamine
Drug class?
Action?
Clinical uses
Drug class: Direct sympathomimetic
Action: Beta 1 agonist
Clinical uses: Heart failure, cardiogenic shock, cardiac stress testing
Phenylephrine
Drug class?
Action?
Clinical uses?
Drug class: Direct sympathomimetic
Action: Alpha 1 agonist
Clinical uses: Hypotension (causes vasoconstriction), before ophthalmic procedures (causes pupil dilation), nasal decongestant
Albuterol
Drug class?
Action?
Related drugs?
Clinical uses?
Drug class: Direct sympathomimetic
Action: Beta 2 agonist, transcellular shift of K+ into cell
Related drugs: Salmeterol (longer acting) and terbutaline
Clinical uses: Albuterol for acute asthma and hyperkalemia at high doses, Salmeterol for long term asthma or COPD control, Terbutaline to reduce premature uterine contractions
Amphetamine
Drug class?
Action?
Clinical uses?
Drug class: Indirect sympathomimetic
Action: Indirect general agonist that works as a re-uptake inhibitor and also releases stored catecholamines
Clinical uses: Narcolepsy and ADD/ADHD
Ephedrine
Drug class?
Action?
Clinical uses?
Drug class: Indirect sympathomimetic
Action: Indirect general agonist that causes release of stored catecholamines
Clinical uses: Nasal decongestant, urinary stress incontinence in women, hypotension
Cocaine
Drug class?
Action?
Clinical uses?
Other?
Drug class: Indirect sympathomimetic
Action: Indirect general agonist that works as a re-uptake inhibitor
Clinical uses: Epistaxis (causes vasoconstriction and local anesthesia)
Other: Never give Beta Blockers if cocaine intoxication is suspected as this can cause extreme hypertension from unopposed Alpha 1 activation
Methylphenidate
Action?
Clinical uses?
Action: Derivative of amphetamine that stimulates the release of catecholamines
Clinical uses: Narcolepsy and ADHD
Reserpine
Action?
Clinical uses?
Side effects?
Action: Inhibits neuron’s ability to store NE, Dopamine, and Serotonin leading to a depletion of these neurotransmitters throughout the body
Clinical uses: Treats hypertension
Side effects: Serious depression and parkinsonism (why this drug is rarely used anymore)
Guanethidine
Action?
Clinical uses?
Side effects?
Action: Inhibits NE release from sympathetic neurons
Clinical uses: Treats hypertension
Side effects: May lead to severe orthostatic hypotension and shock
Clonidine
Action?
Clinical uses?
Side effects?
Action: Alpha 2 agonist (decrease CNS sympathetic outflow)
Clinical uses: Hypertensive emergency (does not decrease renal blood flow, so ideal for hypertensive patients in renal disease)
Side effects: CNS depression, hypotension, bradycardia
Methyldopa
Action?
Causes?
Clinical uses?
Side effects?
Action: Alpha 2 agonist
Causes: Decrease CNS sympathetic activity leading to vasodilation
Clinical uses: Hypertension in pregnancy (safe in pregnancy). Hypertension in renal disease patients (does not decrease renal blood flow).
Side effects: Direct Coombs + hemolytic anemia, sedation, dizziness, SLE-like syndrome
Phenoxybenzamine
Action?
Clinical uses?
Action: IRREVERSIBLE Alpha receptor antagonist
Clinical uses: Pheochromocytoma - used preoperatively and given before beta blockade to prevent hypertensive crisis
Phentolamine
Action?
Clinical uses?
Action: Reversible Alpha receptor anatagonist
Clinical uses: Give to patients on MAO inhibitors who eat Tyramine-containing foods (prevents hypertensive crisis)
Alpha 1 Blockers
Drug examples?
Clinical uses?
Drug examples: Prazosin, Terazosin, Tamsulosin, Doxazosin
Clinical uses: Urinary symptoms of BPH, PTSD (Prazosin), and hypertenson
Alpha 2 Blockers
Drug example?
Clinical uses?
Drug example: Mirtazapine
Mechanism: Blocks pre-synaptic autoreceptors resulting in increased release of NE and Serotonin
Beta Blockers
Drug examples?
Drugs that are more Beta 1 selective blockers (and thus act more at heart)?
Drugs that non-selective Beta blockers?
Drugs that are non-selective alpha and beta blockers?
Drug examples: Metoprolol, Acebutolol, Betaxolol, Carvedilol, Esmolol, Atenolol, Nadolol, Timolol, Pindolol, Labetalol
Drugs that are more selective for blocking Beta 1 receptors (and thus act at the heart): Atenolol, Metoprolol, Esmolol, Acebutolol
Drugs that are non-selective beta blockers: Propranolol, Timolol, Nadolol
Non-selective alpha and beta blockers: Carvedilol and Labetalol
Beta blockers
Clinical uses?
Clinical uses:
Angina (to decrease heart rate and contractility)
MI (beta blockers decrease mortality)
SVT (class 2 antiarrhythmic that decreases AV conduction velocity)
Hypertension (decreased cardiac output, decreased renin release via beta 1 receptor blockage on JGA)
CHF (slows progression of chronic failure - likely due to less fluid retention from renin blockade)
Glaucoma (timolol decreases secretion of aqueous humor)
Beta blockers
Side effects?
Side effects: Impotence, bradycardia, AV block, shortness of breath in asthma or COPD patients (secondary to bronchoconstriction from beta 2 blockade), fasting hypoglycemia.
Fenoldopam
Mechanism of action?
Clinical uses?
Mechanism: D1 dopamine receptor agonist
Clinical uses: Produces vasodilation and treats hypertension (especially in kidney failure patients as D1 receptor causes relaxation of renal smooth muscle)
