Phenylephrine is a man-made drug that stimulates receptors (alpha1 receptors) on blood vessels and cause blood vessels to constrict (vasoconstriction). It is a vasoconstrictor medication, structurally similar to epinephrine and ephedrine. Vasoconstriction increases blood pressure. Phenylephrine increases blood pressure and heart rate without affecting heart rhythm.

NeoSynephrine, Neofrin

GENERIC AVAILABLE: Yes

Yes

Side effects of phenylephrine are headache, reflex bradycardia (slow heart beat), excitability, anxiety, restlessness, high blood pressure, and rarely abnormal heart beats.

Injection: 10 mg/mL supplied as a 1 mL single dose vial

Phenylephrine should be used cautiously with MAO inhibitors like selegiline (Eldepryl, Zelapar), phenelzine (Nardil), isocarboxazid (Marplan), because they can also increase blood pressure and can cause a serious hypertensive episode. A similar reaction occurs when phenylephrine is combined with amphetamine and related drugs.

Phenylephrine should be used with caution with antidepressants like amitriptyline (Elavil, Endep), nortriptyline (Pamelor, Aventyl), doxepin (Sinequan, Adapin), and trazodone (Deyrel). Such anti-depressants may increase blood pressure if used together with phenylephrine.

There are no adequate studies done on phenylephrine to determine safe and effective use in pregnant women.

It is not known whether phenylephrine enters breast milk; therefore, it is best to be cautious before using it in nursing mothers.

What preparations of phenylephrine-injection are available?

Injection: 10 mg/ml

How should I keep phenylephrine-injection stored?

Store phenylephrine injections between 15 C to 30 C (59 to 86 F).