Antiadrenergic Drugs
• Adrenergic Receptor Antagonists
• Sympatholytics
1
,Introduction
Drugs used to block the actions of endogenous
catecholamine (NA and Adr)
Great clinical value
They occupy adrenergic receptors (alpha and beta)
but do not produce signal transduction – Affinity is
there but without intrinsic activity
Clinically 2 (two) distinct groups – alpha blockers
and beta blockers
2
, Contd.
In clinical therapeutics, nonselective antagonists have
been used in the treatment of pheochromocytoma
(adrenal tumors that secrete catecholamines)
Alpha-1 selective antagonists are used in primary
hypertension and benign prostatic hyperplasia
(BPH)
Beta-receptor antagonist - hypertension, ischemic
heart disease, arrhythmias, endocrinologic and
neurologic disorders, and other conditions
Blockade of central nervous system dopamine receptors
is very important – Antiemetic, Antipsychotic and
tricyclic anti-depressants
pheochromocytoma
3
• Adrenergic Receptor Antagonists
• Sympatholytics
1
,Introduction
Drugs used to block the actions of endogenous
catecholamine (NA and Adr)
Great clinical value
They occupy adrenergic receptors (alpha and beta)
but do not produce signal transduction – Affinity is
there but without intrinsic activity
Clinically 2 (two) distinct groups – alpha blockers
and beta blockers
2
, Contd.
In clinical therapeutics, nonselective antagonists have
been used in the treatment of pheochromocytoma
(adrenal tumors that secrete catecholamines)
Alpha-1 selective antagonists are used in primary
hypertension and benign prostatic hyperplasia
(BPH)
Beta-receptor antagonist - hypertension, ischemic
heart disease, arrhythmias, endocrinologic and
neurologic disorders, and other conditions
Blockade of central nervous system dopamine receptors
is very important – Antiemetic, Antipsychotic and
tricyclic anti-depressants
pheochromocytoma
3
