Clinical Pharmacology
Verapamil has a pronounecd antiarrhythmic action particularly in supraventricular cardiac arrhythmias.it prolongs impulse condition in the AV node and thereby depending on the type of arrhythmia restores the sinus rhythm and/or normalises the ventricular rate.
The calcium antagonist verapamil reduces myocardial oxygen consumption directly by intervening in the energy consuming metabolic processes of the myocardial cell and indirectly by diminishing the peripheral resistance (afterload).
The decrease of the vascular smooth muscle tone moreover prevents coronary spasms and lowers raised blood pressure.
Indication for Used
For the treatment of hypertension, angina, and cluster headache prophylaxis.
Mechanism of action
Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known.
Used in Pregnancy ( Category C )
verapamil carries the potential to produce hypocia associated with maternal hypotnsion.
Verapamil side effects
serious side effects:
Less serious verapamil side effects may include:
Half life
2.8-7.4 hours
Dosage of Verapamil
Adult (usual):
Angina: (extended-release) initial: 180 mg po qd at bedtime. Titrate up to 480 mg at bedtime- maximum 540 mg at bedtime. (immediate release) initial: 80 mg po tid - may titrate at daily or weekly intervals to 360 mg daily.
Arrhythmias, supraventricular: (immediate-release) initial: 240-320 mg po daily in 3-4 divided doses. Non-digitalized patients may require up to 480 mg daily in 3-4 divided doses. Arrhythmias, supraventricular: 5-10 mg IV (0.075-0.15 mg/kg) IV bolus over 2 min. May give additional 10 mg after 30 minutes if no response.
Hypertension: (extended-release) initial, 180 mg tablet po qd at bedtime OR 200 mg capsule po qd at bedtime. Maintenance: titrate up to 480 mg TAB qd at hs or 400 mg capsule po qd at hs.
Hypertension: (immediate-release) initial- 80 mg po tid. May titrate at daily or weekly intervals to 360-480 mg daily. Hypertension: (sustained-release) initial: 240 mg orally once daily in the morning. Maintenance (based on response): titrate up to 240 mg bid (tablet) or 480 mg (capsule) once a day in the morning.
Migraine headache, prophylaxis: 80 mg po 3-4 times daily.
Verapamil has a pronounecd antiarrhythmic action particularly in supraventricular cardiac arrhythmias.it prolongs impulse condition in the AV node and thereby depending on the type of arrhythmia restores the sinus rhythm and/or normalises the ventricular rate.
The calcium antagonist verapamil reduces myocardial oxygen consumption directly by intervening in the energy consuming metabolic processes of the myocardial cell and indirectly by diminishing the peripheral resistance (afterload).
The decrease of the vascular smooth muscle tone moreover prevents coronary spasms and lowers raised blood pressure.
Indication for Used
For the treatment of hypertension, angina, and cluster headache prophylaxis.
Mechanism of action
Verapamil inhibits voltage-dependent calcium channels. Specifically, its effect on L-type calcium channels in the heart causes a reduction in ionotropy and chronotropy, thuis reducing heart rate and blood pressure. Verapamil's mechanism of effect in cluster headache is thought to be linked to its calcium-channel blocker effect, but which channel subtypes are involved is presently not known.
Used in Pregnancy ( Category C )
verapamil carries the potential to produce hypocia associated with maternal hypotnsion.
Verapamil side effects
serious side effects:
- fast or slow heartbeats;
- feeling like you might pass out;
- fever, sore throat, and headache with a severe blistering, peeling, and red skin rash;
- feeling short of breath, even with mild exertion;
- swelling, rapid weight gain; or
- nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).
Less serious verapamil side effects may include:
- constipation, nausea;
- skin rash or itching;
- dizziness, headache, tired feeling; or
- warmth, itching, redness, or tingly feeling under your skin.
Half life
2.8-7.4 hours
Dosage of Verapamil
Adult (usual):
Angina: (extended-release) initial: 180 mg po qd at bedtime. Titrate up to 480 mg at bedtime- maximum 540 mg at bedtime. (immediate release) initial: 80 mg po tid - may titrate at daily or weekly intervals to 360 mg daily.
Arrhythmias, supraventricular: (immediate-release) initial: 240-320 mg po daily in 3-4 divided doses. Non-digitalized patients may require up to 480 mg daily in 3-4 divided doses. Arrhythmias, supraventricular: 5-10 mg IV (0.075-0.15 mg/kg) IV bolus over 2 min. May give additional 10 mg after 30 minutes if no response.
Hypertension: (extended-release) initial, 180 mg tablet po qd at bedtime OR 200 mg capsule po qd at bedtime. Maintenance: titrate up to 480 mg TAB qd at hs or 400 mg capsule po qd at hs.
Hypertension: (immediate-release) initial- 80 mg po tid. May titrate at daily or weekly intervals to 360-480 mg daily. Hypertension: (sustained-release) initial: 240 mg orally once daily in the morning. Maintenance (based on response): titrate up to 240 mg bid (tablet) or 480 mg (capsule) once a day in the morning.
Migraine headache, prophylaxis: 80 mg po 3-4 times daily.
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Ditulis oleh:
Unknown - Saturday, 14 May 2011
