Sympatholytic

A sympatholytic drug is a medication which inhibits the postganglionic functioning of the sympathetic nervous system (SNS). Though some are indicated for various functions, they can all be used as antihypertensives.

Antiadrenergic

Antiadrenergic agents inhibit the signals of epinephrine and norepinephrine. They are primarily adrenergic antagonists, inhibiting adrenergic receptors, but there are exceptions: clonidine is an adrenergic agonist on the α2 receptor, since this receptor is located presynaptically to inhibit further release of adrenaline and noradrenaline.

Other ways of inhibiting adrenergic signaling is by catecholamine synthesis blocking, e.g. by methyltyrosine. Reserpine works by inhibiting transport into synaptic vesicles of noradrenaline by inhibiting the VMAT transporter.

In hypertension

Many antiadrenergic agents used as antihypertensives include:

• centrally acting:
• Clonidine (α2 agonist)
• Guanfacine (α2 agonist)
• Methyldopa (α2 agonist)
• Moxonidine (imidazoline receptor agonist)
• Rescinnamine (ACE inhibitor)
• Reserpine (VMAT inhibitor)
• Rilmenidine (imidazoline receptor agonist)
• ganglion-blocking
• Mecamylamine (α3β4 nicotinic receptor inhibitor)
• Trimethaphan (ganglion type receptor inhibitor)
• peripherally acting
• Prazosin (α1 antagonist)
• Guanethidine (Magnesium-ATPase inhibitor)
• Indoramin (α1 antagonist)
• Doxazosin (alpha blocker)

References

External links