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
