Calcium channel blockers Flashcards
What is a calcium channel?
A Voltage gated channel that lies on the cell membrane and regulate Ca flow
What are some bodily processes that require Calcium ions?
(L-type of long lasting calcium channel)-
Cardiac tissue contraction - SAN, AVN
The excitation-contraction coupling in skeletal, smooth and cardiac muscle
Production of aldosterone. (Fluid retention > elevation of BP)
Whats the importance of L-type long lasting calcium channels?
They manage the electrical signalling of cells, by allowing the selective diffusion of calcium ions.
This is in response to changes in cellular membrane potential
What are some of the therapeutic indications for calcium channel blockers?
Hypertension (CCBs reduce BP)
Angina
Cardiac Arrythmia
Vascular spasm
What effect does CCB produce in vascular smooth muscle?
The inhibition of Ca into the cell causes a reduction of vascular contraction
What are dihydropyridines?
A class of calcium channel blockers, they are; Vasodilators, reduce arterial pressure and reduce vascular resistance
Give examples of ccb for vascular smooth muscle.
Amlodpine
Nifedipine
Felodipine
What are the possible side effects of CCBs? (for vascular smooth muscle)
Vasodilatation - flushing, headaches
What is the equation to calculate blood pressure?
Cardiac output x Peripheral resistance
How do CCBs work for angina (coronary artery spasm)?
They relieve symptoms of angina by causing vasodilation.
What is an arrhythmia?
Abnormal heart rhythm - failure of SAN to maintain beat
What are some symptoms of an arrhythmia?
Palpitations
Breathless
Weakness/fatigue
What are non-dihydropyridines?
They are less effective vasodilators, they have additional effects on the heart which can control a rapid heart beat.
State two CCBs effective on the myocardium
Verapamil
Diltiazem
What is angina?
Angina is chest pain due to a reduced blood flow to the heart due to narrowing of the arteries.
The heart muscles are not getting enough oxygen.
