Inhalative

Inhalative refers to the administration or action of substances via inhalation, delivering agents through the respiratory tract by breathing in air or a prepared gas, vapor, or aerosol. This route is used in medicine, toxicology, and occupational health and contrasts with oral, intravenous, or other routes.

Mechanism and pharmacokinetics: Inhalative delivery relies on the alveolar surface to rapidly absorb volatile or aerosolized substances into the pulmonary circulation. The onset of action is often rapid due to large surface area and high perfusion. For volatile inhalative anesthetics (for example isoflurane, sevoflurane, desflurane), the onset and offset depend on the blood–gas partition coefficient; low solubility yields faster induction and recovery. Elimination is largely via exhalation, and metabolism may play a minor role for some agents.

Applications: Inhalative anesthesia uses volatile agents for general anesthesia. Inhaled bronchodilators (beta-agonists like salbutamol) and inhaled corticosteroids are inhalative therapies for asthma and COPD, delivered by inhalers or nebulizers to improve lung deposition and reduce systemic exposure.

Safety and limitations: Potential airway irritation and coughing can occur; systemic effects depend on the agent and dose. Environmental impact is a consideration for volatile anesthetics, which can contribute to greenhouse gas emissions. Proper dosing, monitoring, and device-appropriate administration (inhalers, nebulizers, ventilators) are essential. Not all substances are suitable for inhalative use; some may be toxic to the lungs if inhaled inappropriately.

History and terminology: The term inhalative derives from Latin inhalare and is used in various languages, including German. In English, “inhalational” is more common, but “inhalative” appears in pharmacology and toxicology literature to denote the route of administration.