A-23. Drugs used for hypertension II. Ca2+-channel blockers and other vasodilators Flashcards
What are the dihydropyridine calcium channel blockers (10)
Nifedipine Nitrendipine Nimodipine Nicardipine Nisoldipine Clevidipine Felodipine Amlodipine Lacidipine Isradipine
What is the phenylalkylamines calcium channel blockers
Verapamil
What are the Benzothiazepine calcium channel blockers?
Diltiazem
Mode of action of calcium channel blockers?
Inhibition of L-type calcium channel
Where do CCB have their effect?
They cause vasodilation and reduces BP in the smooth muscle, including bronchiolar, GI, and uterine SM
(Makes them good meds for COPD since they relax the bronchi SM)
And in some cases (Verapamil, Diltiazem) affect cardiac muscle as well
Which CCB are coronary specific
Nicardipine and nisoldipine (50x more affinity)
Which CCB is cerebral vessel specific
Nimodipine
The CCB that act on cardiac muscle specifically causes?
act on L type calcium channel causing decreased pacemaker activity, AV conduction, and contractility
Indications of CCB listed
- ) Hypertension
- ) Angina
- ) Arrhythmias
- ) Atherosclerosis
- ) Raunaud’s phenomenon
- ) Peripheral vasoconstriction
- ) Migraine prophylaxis
- ) GI spasms
- ) Subarachnoid hemorrhage prevention
Which CCB is used in pregnancy? In combination of what?
In the 1st and 2nd trimester nifedipine is used in combo with alpha-methyldopa
What is used in hypertensive emergencies? Chronic?
Sublingual/mouth spray nifedipine (5 min onset) or IV nifedipine/clevidipine
For chronic treatment use longer release CCB
How does CCB work for Angina and which drugs?
Used for Prinzmetal Angina?
Effort Angina?
1.)They increase peripheral vasodilation decreasing afterload
2.)Coronary vasodilation (such as Nifedipine and nicardipine)
3.)Cardio-depressant effects and tissue protective effects via decreased Ca levels causes decreased oxidation
Prinzmetal angina is treated with any CCB as first line treatment (usually nifedipine)
Effort angina treated with verapamil or diltiazem, decreased inotropy causes decreased load on heart and longer time in diastole phase (more oxygen)
Unstable angina contraindications?
Nifedipine is contraindicated due to coronary steal syndrome and reflex tachycardia
Drugs used in Supraventricular tachycardias like A Fib
Verapamil and Diltiazem
CCBs used in atherosclerosis
Lacidipine and isradipine
Lacidipine mechanism of action
high affinity for cholesterol rich tissues, so atherosclerotic plaque, and slowly diffuses out to receptor like depot
Isradipine MOA
Improves lipid profile and increases HDL
Nimodipine used for?
subarachnoid hemorrhage prevention in patients with berry aneurysms or prevent vasospasms following an SAH
Which drug is used for Migraine
Verapamil
Which drug is used for GI spasms
Pinacerine
Kinetics of of CCBs
Good oral absorption, high pass effect, high plasma protein binding, and extensive metabolism
Short acting (2-7 hours) CCBs
Verapamil, Diltiazem, Nicardipine, Nimodipine, and Nifedipine (the shortest acting one lasting 2 hours)