MECHANISM OF ACTION –
Prazosin acts by inhibiting the postsynaptic alpha(1)-adrenoceptors on vascular smooth muscle. This inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
PHARMACOLOGICAL ACTION –
1- Prazosin is a selective inhibitor of the alpha1 subtype of alpha adrenergic receptors.
2- In the human prostate, Prazosin antagonizes phenylephrine (alpha1 agonist)-induced contractions, in vitro and binds with high affinity to the alpha1c adrenoreceptor, which is thought to be the predominant functional type in the prostate.
3- The antihypertensive effect of Prazosin results from a decrease in systemic vascular resistance and the parent compound Prazosin is primarily responsible for the antihypertensive activity.
USES –
1. Used to treat hypertension.
2. It has also been used to decrease urinary obstruction and relieve symptoms associated with symptomatic benign prostatic hyperplasia. a1-Receptors mediate contraction and hypertrophic growth of smooth muscle cells. Antagonism of these receptors leads to smooth muscle relaxation in the peripheral vasculature and prostate gland.
3. Prazosin has also been used in conjunction with cardiac glycosides and diuretics in the management of severe congestive heart failure.
4. It has also been used alone or in combination with ß-blockers in the preoperative management of signs and symptoms of pheochromocytoma.
SIDE EFFECTS –
1-Dizziness or lightheadednessfainting (sudden)
2-Loss of bladder control
3-pounding heartbeat
4-swelling of the feet or lower legs
5-Chest pain
6-trouble breathing
DRUG-DRUG INTERACTION –
1-Prazosin + Acebutolol = may increase the orthostatic hypotensive activities of Prazosin.
2-Prazosin +Alfuzosin = may increase the antihypertensive activities of Alfuzosin.
3-Prazosin + Atenolol = may increase the orthostatic hypotensive activities of Prazosin.
REFERENCE-
Tripathi K.D,"Essentials of medical pharmacology",7th edition,page no.127
Prazosin acts by inhibiting the postsynaptic alpha(1)-adrenoceptors on vascular smooth muscle. This inhibits the vasoconstrictor effect of circulating and locally released catecholamines (epinephrine and norepinephrine), resulting in peripheral vasodilation.
PHARMACOLOGICAL ACTION –
1- Prazosin is a selective inhibitor of the alpha1 subtype of alpha adrenergic receptors.
2- In the human prostate, Prazosin antagonizes phenylephrine (alpha1 agonist)-induced contractions, in vitro and binds with high affinity to the alpha1c adrenoreceptor, which is thought to be the predominant functional type in the prostate.
3- The antihypertensive effect of Prazosin results from a decrease in systemic vascular resistance and the parent compound Prazosin is primarily responsible for the antihypertensive activity.
USES –
1. Used to treat hypertension.
2. It has also been used to decrease urinary obstruction and relieve symptoms associated with symptomatic benign prostatic hyperplasia. a1-Receptors mediate contraction and hypertrophic growth of smooth muscle cells. Antagonism of these receptors leads to smooth muscle relaxation in the peripheral vasculature and prostate gland.
3. Prazosin has also been used in conjunction with cardiac glycosides and diuretics in the management of severe congestive heart failure.
4. It has also been used alone or in combination with ß-blockers in the preoperative management of signs and symptoms of pheochromocytoma.
SIDE EFFECTS –
1-Dizziness or lightheadednessfainting (sudden)
2-Loss of bladder control
3-pounding heartbeat
4-swelling of the feet or lower legs
5-Chest pain
6-trouble breathing
DRUG-DRUG INTERACTION –
1-Prazosin + Acebutolol = may increase the orthostatic hypotensive activities of Prazosin.
2-Prazosin +Alfuzosin = may increase the antihypertensive activities of Alfuzosin.
3-Prazosin + Atenolol = may increase the orthostatic hypotensive activities of Prazosin.
REFERENCE-
Tripathi K.D,"Essentials of medical pharmacology",7th edition,page no.127
No comments:
Post a Comment