1. Analgesics Compounds capable of relieving pain without the loss of CONSCIOUSNESS. 2. Antihypertensive Agents Drugs used in the treatment of acute or chronic vascular HYPERTENSION regardless of pharmacological mechanism. Among the antihypertensive agents are DIURETICS. 3. Sympatholytics Drugs that inhibit the actions of the sympathetic nervous system by any mechanism. The most common of these are the ADRENERGIC ANTAGONISTS and drugs that deplete norepinephrine or reduce the release of transmitters from adrenergic postganglionic terminals. Drugs that act in the central nervous system to reduce sympathetic activity are included here. 4. Adrenergic alpha-2 Receptor Agonists Compounds that bind to and activate ADRENERGIC ALPHA-2 RECEPTORS. | 
