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1. diminishing any function or activity; see also depressor.
2. an agent that retards any function, especially a drug that acts on the central nervous system to depress activity at all levels by stabilizing neuronal membranes. Central nervous system depressants such as barbiturates and inhalational anesthetics are used as sedatives, hypnotics, and anesthetics. alcohol is also a depressant, although its first effect is sometimes stimulating.
cardiac depressant an agent that depresses the rate or force of contractions of the heart.
An agent that decreases heart rate and contractility.
See also: depressant