Calcium-Channel Blockers
nifedipine
machanism of action
The mechanism by which nifedipine reduces arterial blood pressure involves peripheral arterial vasodilatation and, consequently, a reduction in peripheral vascular resistance. The increased peripheral vascular resistance, an underlying cause of hypertension, results from an increase in active tension in the vascular smooth muscle. Studies have demonstrated that the increase in active tension reflects an increase in cytosolic free calcium
Contraindications
in patients with a known hypersensitivity to any component of the tablet.
must not be used in cases of cardiogenic shock.
SIDE EFFECTS
Dizziness, flushing, weakness, swelling ankles/feet, constipation, and headache may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.
INDICATIONS
Adalat CC is indicated for the treatment of hypertension. It may be used alone or in combination with other antihypertensive agents.
Storage
store in the room condition away from light and keep reach out of children
Route of administration
oral(Initially, 30 to 60 mg PO once daily. Titrate upwards as necessary. Maximum dosage is 90 mg/day PO.)
verapamil
INDICATIONS
for oral use is indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure reduces the risk of fatal and nonfatal cardiovascular events, primarily stokes and myocardial infarctions.
Route of administration
Administer Verelan PM once daily at bedtime. Clinical trials studied doses of 100 mg, 200 mg, 300 mg and 400 mg. The usual daily dose of extended-release Verelan PM in clinical trials has been 200 mg given by mouth once daily at bedtime
Storage
Store at 25°C (77°F); excursions permitted to 15-30°C. Protect from moisture.
Dispense in tight, light-resistant container
SIDE EFFECTS
Dizziness, slow heartbeat, constipation, stomach upset, nausea, headache, or tiredness may occur.
Mechanism Of Action
CONTRAINDICATIONS
Severe left ventricular dysfunction
Hypotension (less than 90 mm Hg systolic pressure) or cardiogenic shock.
Sick sinus syndrome (except in patients with a functioning artificial ventricular pacemaker).
Second- or third-degree AV block (except in patients with a functioning artificial ventricular pacemaker).
Verapamil is a calcium ion influx inhibitor (L-type calcium channel blocker or calcium channel antagonist). Verapamil exerts its pharmacologic effects by selectively inhibiting the transmembrane influx of ionic calcium into arterial smooth muscle as well as in conductile and contractile myocardial cells without altering serum calcium concentrations. Verapamil binding is voltage-dependent with affinity increasing as the vascular smooth muscle membrane potential is reduced. In addition, verapamil binding is frequency dependent and apparent affinity increases with increased frequency of depolarizing stimulus.