Androgenetic Drugz Flashcards
Phenylephrine
Causes vasoconstriction: a1 effect.
USES
* Nasal decongestant. Given orally or topically.
* Mydriatic.
Clonidine
Partial a2 agonist.
* Centrally-acting antihypertensive.
* Activates central presynaptic 2-adrenoceptors.
* Reduces sympathetic outflow → reduces blood pressure.
Isoproterenol
Activates B1 and B2 adrenergic receptors.
* CVS effects
* B1 effect → Increases heart rate, force of contraction and cardiac
output
* B2 effect → Dilates arterioles of skeletal muscle → decrease in
peripheral vascular resistance.
* Diastolic pressure falls. Systolic blood pressure may remain
unchanged or rise.
* Mean arterial pressure typically falls.
* Causes bronchodilation (B2 effect).
* Isoproterenol may be used in emergencies to stimulate heart rate in
patients with bradycardia or heart block.
Dobutamine
Predominantly a B1 agonist. Given IV.
* Potent inotrope, with comparatively mild chronotropic effects.
* Produces less increase in HR and less decrease in PVR than
isoproterenol.
* Causes mild vasodilation.
* Increases myocardial O2 consumption→ basis of the dobutamine
stress echocardiogram.
Management of acute heart failure.
* Management of cardiogenic shock
Albuterol
Causes bronchodilation (B2 effect).
* Used with ICS in asthma
* DOC for acute asthma attacks
Amphetamine
Has central stimulatory action.
* Can increase blood pressure by -agonist action on vasculature as
well as a-stimulatory effects on heart.
USES
* ADHD
* Narcolepsy
Tyramine
Found in fermented foods such as ripe
cheese and Chianti wine.
* Normally oxidized by MAO.
* If the patient is taking MAO inhibitors, it
can precipitate serious vasopressor
episodes.
* MAO inhibitors are used as
antidepressants.
(Consume wine or cheese? You’re making it worse._
Cocaine
Blocks monoamine reuptake.
* Monoamines accumulate in synaptic space.
* This results in potentiation and prolongation of their central and
peripheral actions.
Ephedrine
Not acatecholamine 🡑 poor substrate for COMT and MAO 🡑 long
duration.
* Penetrates the CNS.
USES
* Usedas a pressor agent, particularly during spinal anesthesia
Pseudoephedrine
One of four ephedrine enantiomers.
* Available over the counter as a component of many decongestant
mixtures.
Phenoxybenzamine
Irreversible antagonist at a1 and a2 receptors
* Unsuccessful for hypertension
Uses:
* Pheochromocytoma- Prior to surgical removal of a tumor- Chronic management of inoperable tumors
Phentolamine
Reversibly blocks a1 and a2 receptors
Uses:* Pheochromocytoma: control of hypertension during
preoperative preparation and surgical excision- Diagnosis of pheochromocytoma: phentolamine blocking test
* Prevention of dermal necrosis after extravasation of
norepinephrine
*Cocaine-induced acute coronary syndrome: to reverse coronary
artery vasoconstriction
* Hypertensive crisis due to:- Stimulant drug overdose- Sudden withdrawal of sympatholytic antihypertensive drugs
(eg: clonidine)-Interaction between MAOIs and tyramine or other
sympathomimetic amines
Prazosin, Terazosin, Doxazosin, Tamsulosin
Selective blockers of the a1-receptor
Uses: *Treatment of hypertension (not drugs of choice)
* Treatment of Benign Prostatic Hyperplasia (BPH)- Drug of choice for symptom relief- Relaxes smooth muscle in the bladder neck, prostate
capsule and prostatic urethra, improving urinary flow
CVEffects
* Lowers arterial blood pressure by relaxing both arterial and
venous smooth muscle
*First dose produces an exaggerated hypotensive response that
can result in syncope (fainting)
* The first does must be 1/4 or 1/3 of normal dose
Prazosin
(prototype) analogs with longer half-life
Terazosin
Doxazosin
Treatment of hypertension and BPH
Tamsulosin
Three subtypes of the α1-receptor: α1A, α1B, α1D
* The α1A-receptorpredominates in GU smooth muscle
* Selective for α1A-receptors
* Approved for BPH
* Little effect on blood pressure
* Less likely to cause orthostatic hypotension
Atenolol
Metoprolol
Useful in hypertensive patients with impaired pulmonary function
Useful in diabetic hypertensive patients who are receiving
insulin or oral hypoglycemic agents
Esmolol
Ultra-short acting
* Half-life ~10 minutes
* IV administration
* Used for rapid control of ventricular rate in patients with
atrial fibrillation or atrial flutter
Pindolol
Maybe preferred in individuals with diminished cardiac reserve
or a propensity to bradycardia
Labetalol
Competitive antagonist at B and A1 receptors
* Substantially more potent as a B-antagonist than as an α-antagonist
* Used in hypertension
Carvedilol
Similar to Labetalol
* Antioxidant properties
* Used in hypertension and CHF
