Phenylephrine (Neo-Synephrine) Flashcards

Phenylephrine (Neo-Synephrine) Overview

• Classified as a nasal decongestant, mydriatic agent, and antihypotensive.
• Functions as an adrenergic drug that mimics sympathetic nerve activity.

Administration Routes

• Intranasal: Reduces nasal congestion by constricting small vessels in the nasal mucosa when applied as sprays or drops.
• Topical: Used in ophthalmic examinations to dilate pupils without significant cycloplegia.
• Parenteral: Effective in reversing acute hypotension from spinal anesthesia or vascular shock. Produces fewer cardiac side effects due to lack of beta-adrenergic activity.

Side Effects

• Common side effects include anxiety, restlessness, and tremor due to central nervous system stimulation.
• Less frequent effects with topical and intranasal use; prolonged intranasal usage may induce mucosal burning and rebound congestion.

Administration Alerts

• Parenteral use can cause tissue injury from extravasation.
• Ophthalmic drops may damage soft contact lenses.
• Classified as Pregnancy Category C.

Adverse Effects

• Topical/intranasal: Rare side effects, but prolonged use can lead to burning and narrow-angle glaucoma scenarios.
• Parenteral use can increase blood pressure and cause ventricular tachycardia, especially in patients with cardiovascular issues.

Contraindications

• Not recommended for patients with acute pancreatitis, heart disease, hepatitis, or narrow-angle glaucoma.

Overdose Management

• Managed with phentolamine (Regitine) to decrease blood pressure.

Expected Actions & Uses

• Acts as a selective alpha-adrenergic agonist with various formulations (intranasal, ophthalmic, IM, SQ, IV).
• Its actions are extensions of sympathetic stimulation, targeting similar responses as anticholinergic agents.

Desired Therapeutic Response

• Directly or indirectly stimulates the sympathetic nervous system, leading to various physiological responses associated with this system.

Test your knowledge on Phenylephrine (Neo-Synephrine) with these flashcards. Learn about its therapeutic and pharmacologic classifications, as well as administration methods. Perfect for students studying pharmacology or healthcare practitioners.