Respirant

Respirant is a historical and pharmacological term used to describe an agent that promotes respiration. The category covers substances that stimulate breathing through two main mechanisms: central action on the respiratory center in the brain, and peripheral action by irritating nasal or airway receptors to trigger a reflex increase in ventilation. Because of these differing modes, respirants can function as mild central stimulants or as local irritants.

Historically, respirants were employed to revive individuals experiencing faintness, mild respiratory depression, or reduced breathing. Classic examples include ammonia-based smelling salts, which emit vapors that irritate the mucosa and induce a quick inhalation response. Other volatile agents such as camphor or certain essential oils have been described as mild respirants in traditional practice. In modern medical terminology, the use of broad “respirant” labels has diminished in favor of more specific categories.

In contemporary medicine, respiratory support tends to rely on targeted interventions such as supplemental oxygen, bronchodilators, ventilatory support, and, when indicated, specific respiratory stimulants with defined indications. The term respirant is now mainly of historical interest or used in discussions of older pharmacopoeias and traditional practices. Related concepts include respiratory stimulants in a more precise pharmacological sense, as well as expectorants and bronchodilators, which have distinct therapeutic roles.

See also: respiratory stimulant, bronchodilator, expectorant.