Smooth Muscle Pharm. Flashcards
What are the applications for drug induced smooth muscle relaxation? (3 items)
Vasodilation - Cardiovascular
Uterine relaxation - Obstetric
Bonchodilation - Pulmonary
What is the MOA of organic nitrates?
RNO2 enters smooth muscle –> becomes s-nitroso-thiol –> becomes NO –> increases cGMP –> smooth muscle relaxation
Is the relaxation by organic nitrates venous or arterial dominant?
venous dominant
What are three examples of organic nitrates?
Nitroglycerin
Isosorbide dinitrate
Isosorbide-5-mononitrate
How is sodium Nitroprusside different in MOA than organic nitrates?
It enters smooth muscle cell as NO instead of NO2
Does Nitroprusside affect venous or arterial smooth muscle?
Both
What is the primary use for Nitroprusside?
Hypertensive emergencies
What is the mechanism for Hydralazine?
Directly increases cGMP –> direct vasodilation
Does Hydralazine cause arterial or venous dilation?
arterial
Oral Hyrdalazine is combined with what medication for heart failure?
Isosorbide dinitrate
What type of medication is Minoxidil?
Direct vasodilator
<p>What is the mechanism for Minoxidil?</p>
<p>K+ ATP sensitive channel opener--> resulting in efflux of K+ --> resulting in arterial smooth muscle relaxation</p>
What is the major side effect for Minoxidil?
What is given with Minoxidil to combat this?
Fluid retention/Peripheral edema
Combine with diuretics
What type of medication is Diazoxide?
K+ channel opening vasodilator
Why can Diazoxide be used to treat hypoglycemia?
It inhibits insulin release from pancreas
What is the mechanism for Diazoxide in lowering blood pressure?
Opens K+ channels which causes net efflux of K+ and closes Ca+ channels preventing influx of Ca+ ultimately resulting in decreased vascular tone.
What is the mechanism for Phosphodiesterase inhibitors (PDE3/PDE5 inhibitors)? (2 locations)
In cardiac muscle, PDE3 inhibitors prevents the degradation of cAMP to AMP increasing its relative concentration and increasing cardiac muscle contraction.
In vascular smooth muscle, PDE5 inhibitors prevents the degradation of cGMP to GMP resulting in a relative increase in cGMP concentration resulting in relaxation of smooth muscle.
What are three examples of Phosphodiesterase (PDE3) inhibitors?
Milrinone
Inamrinone
Cilostazol
What is the primary therapeutic use for PDE3 inhibitors?
Heart Failure
What are two examples of PDE5 inhibitors?
Sildenafil
Tadalafil
What is the primary therapeutic use for PDE5 inhibitors?
Erectile dysfunction
What is a miscellaneous Vasodilator the uses the B2 receptor? Does it affect arterial or venous smooth muscle?
Bradykinin
It affects both arterial and venous circulation
What is a miscellaneous vasodilator that utilizes the D1 receptor?
Does it affect arterial or venous circulation?
Fenoldopam
It affects arteries and veins
What is Fenoldopam’s primary effect?
Increased renal blood flow & Na excretion
What is a miscellaneous vasodilator that blocks alpha-adrenergic receptors?
Prazosin
What is the prototype TOcolytic drug for this course?
What type of action does it have?
aTOsiban
Nonapeptide oxytocin antagonism
What is the therapeutic use for Atosiban?
Prevention of preterm labor and inhibition of uterine contractions
What are some examples of B2 agonist bronchodilators? (5 options)
Albuterol Pirbuterol Terbutaline Salmeterol Formoterol
What is the MOA for B2 adrenergic agonists?
Agonism of B2 increases concentrations of cAMP and PKA which promote bronchial smooth muscle relaxation.
What cardiac effect can elevated/toxic doses create?
Tachycardia
What are two examples of anti-cholinergic respiratory medications?
Ipratropium
Tiotropium
How does Methylxanthine work and to what effect?
Adenosine Receptor Antagonism
Bronchodilation
