intranasally

Intranasally describes a route of administration in which a substance is delivered through the nasal passages to the nasal mucosa. This can produce local effects in the nose, such as relief from allergic rhinitis, or systemic effects when the substance is absorbed into the bloodstream. It is used for medicines, vaccines, analgesics, and emergency treatments delivered as nasal sprays.

Advantages of intranasal administration include a relatively rapid onset of action, non-invasiveness, and avoidance of first-pass metabolism in the liver, which can improve bioavailability for certain compounds. It can be convenient for patients who have difficulty swallowing or require quick action. Some agents may also be explored for nose-to-brain delivery, though this is variable and not relied upon for routine therapies.

Forms and devices used for intranasal delivery typically include solutions or suspensions delivered with nasal sprays, droppers, or nebulizers. Dose accuracy depends on device design and user technique. Local tolerability is a consideration, as some formulations can cause nasal irritation, dryness, or sneezing.

Limitations and safety considerations include variability in absorption due to nasal mucosa condition, mucociliary clearance, and individual differences. Not all drugs are suitable for intranasal delivery, and formulations must be stable in nasal fluids and compatible with the mucosa. Potential adverse effects include nasal irritation or bleeding. Examples of intranasal use include naloxone nasal spray for overdose, intranasal corticosteroids for allergies, intranasal vaccines such as live attenuated influenza vaccines, and certain pain or emergency medications.