| OCA | Oral contraceptives agents |
|---|---|
| OHA | Oral hypoglycaemic agents |
| anticarcinogenic agents | Agents that reduce the frequency or rate of spontaneous or induced tumours independently of the mechanism involved. They differ from antineoplastic agent in that they prevent neoplasms from forming. The anticarcinogenic substances can be divided into three categories. The first consists of compounds that prevent the formation of carcinogens from precursor substances. The second group consists of "blocking agents" which inhibit carcinogenesis by preventing carcinogenic agents from reaching or reacting with critical target sites in the tissues. The third group is the "suppressor agents" which act by suppression of expression of neoplasia in cells previously exposed to carcinogens that would otherwise cause neoplasms. (12 Dec 1998) |
|---|---|
| anticestodal agents | Agents used to treat tapeworm infestations in man or animals. (12 Dec 1998) |
| anticholesteraemic agents | Substances that promote a reduction of blood cholesterol levels. (12 Dec 1998) |
| anti-coagulant agents | Medications, like heparin, used as blood-thinners to prevent blood clots and to maintain open blood vesssels. (12 Dec 1998) |
| antidepressive agents | Mood-stimulating drugs used primarily in the treatment of affective disorders and related conditions. Several monoamine oxidase inhibitors are useful as antidepressants apparently as a long-term consequence of their modulation of catecholamine levels. The tricyclic compounds useful as antidepressive agents (antidepressive agents, tricyclic) also appear to act through brain catecholamine systems. A third group (antidepressive agents, second-generation) is a diverse group of drugs including some that act specifically on serotonergic systems. (12 Dec 1998) |
| antidepressive agents, second-generation | A structurally and mechanistically diverse group of drugs that are not tricyclics or monoamine oxidase inhibitors. The most clinically important appear to act selectively on serotonergic systems, especially by inhibiting serotonin reuptake. (12 Dec 1998) |
| antidepressive agents, tricyclic | Substances that contain a fused three-ring moiety and are used in the treatment of depression. These drugs block the uptake of norepinephrine and serotonin into axon terminals and may block some subtypes of serotonin, adrenergic, and histamine receptors. However the mechanism of their antidepressant effects is not clear because the therapeutic effects usually take weeks to develop and may reflect compensatory changes in the central nervous system. (12 Dec 1998) |
| anti-dyskinesia agents | Drugs used in the treatment of movement disorders. most of these act centrally on dopaminergic or cholinergic systems. Among the most important clinically are those used for the treatment of parkinson disease (antiparkinson agents) and those for the tardive dyskinesias. (12 Dec 1998) |
| antifoaming agents | Agents used to prevent the formation of foam or to treat flatulence or bloat. (12 Dec 1998) |
| antifungal agents | Agents destructive to fungi, suppressing their growth or reproduction, and effective against fungal infections. They differ from fungicides, industrial in that antifungal agents are restricted to action against fungi present in human or animal tissues. (12 Dec 1998) |
| anti-HIV agents | Agents used to treat aids and/or stop the spread of the HIV infection. These do not include drugs used to treat symptoms or opportunistic infections associated with aids. (12 Dec 1998) |
| antihypertensive agents | Drugs used in the treatment of acute or chronic hypertension regardless of pharmacological mechanism. Among the antihypertensive agents are diuretics (especially diuretics, thiazide), adrenergic beta-antagonists, adrenergic alpha-antagonists, angiotensin-converting enzyme inhibitors, calcium channel blockers, ganglionic blockers, and vasodilator agents. (12 Dec 1998) |
| anti-infective agents, local | Substances used on humans and other animals that destroy harmful microorganisms or inhibit their activity. They are distinguished from disinfectants, which are used on inanimate objects. (12 Dec 1998) |
| anti-infective agents, quinolone | A group of synthetic antimicrobial agents which usually contain a 4-quinolinone ring structure. A few compounds belonging to this group have related nitrogen heterocyclic ring structures such as naphthyridine or phthalazine groups. All compounds in this group are substituted with an oxo group at the 4-position. The second-generation quinolones are also substituted with a 1-piperazinyl group at the 7-position and a fluorine moiety at the 6-position. The quinolones inhibit the a subunit of DNA gyrase and thus interfere with the ability of the enzyme to repair bacterial DNA breaks during replication. The compounds have a broad spectrum of activity against a variety of aerobic bacteria. (12 Dec 1998) |
| anti-infective agents, urinary | Substances capable of killing agents causing urinary tract infections or of preventing them from spreading. (12 Dec 1998) |