- High Blood Pressure Slideshow Pictures
- Take the Salt Quiz!
- Lowering Blood Pressure Exercise Tips Pictures
- What is phenylephrine-injection, and how does it work (mechanism of action)?
- What brand names are available for phenylephrine-injection?
- Is phenylephrine-injection available as a generic drug?
- Do I need a prescription for phenylephrine-injection?
- What are the side effects of phenylephrine-injection?
- What is the dosage for phenylephrine-injection?
- Which drugs or supplements interact with phenylephrine-injection?
- Is phenylephrine-injection safe to take if I'm pregnant or breastfeeding?
- What else should I know about phenylephrine-injection?
What is phenylephrine-injection, and how does it work (mechanism of action)?
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.
What are the side effects of phenylephrine-injection?
Side effects of phenylephrine are headache, reflex bradycardia (slow heart beat), excitability, anxiety, restlessness, high blood pressure, and rarely abnormal heart beats.
What is the dosage for phenylephrine-injection?
Injection: 10 mg/mL supplied as a 1 mL single dose vial
Which drugs or supplements interact with phenylephrine-injection?
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.
Is phenylephrine-injection safe to take if I'm pregnant or breastfeeding?
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 else should I know about phenylephrine-injection?
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).
Quick GuideHow to Lower Blood Pressure: Exercise Tips

Summary
Phenylephrine hydrochloride injection (NeoSynephrine, Neofrin) is a prescription drug used for the maintenance of blood pressure during treatment of vascular failure in shock, drug-induced high blood pressure, and PSVT during anesthesia. Side effects, drug interactions, storage, dosage, and pregnancy safety information should be reviewed prior to taking any medication.
Related Disease Conditions
-
High Blood Pressure (Hypertension) Signs, Causes, Diet, and Treatment
High blood pressure (hypertension) is a disease in which pressure within the arteries of the body is elevated. About 75 million...
-
High Blood Pressure Treatment (Natural Home Remedies, Diet, Medications)
High blood pressure (hypertension) means high pressure (tension) in the arteries. Treatment for high blood pressure include...
-
Abnormal Heart Rhythms (Heart Rhythm Disorders)
Heart rhythm disorders vary from minor palpitations, premature atrial contractions (PACs), premature ventricular contractions...
-
Shock (Medical)
Medical shock is a life-threatening medical condition. There are several types of medical shock, including: septic shock,...
-
Paroxysmal Supraventricular Tachycardia (PSVT)
Paroxysmal supraventricular tachycardia (PSVT) is an abnormal conduction of electricity in particular areas of the heart. PSVT...
Treatment & Diagnosis
Medications & Supplements
From 
Heart Health Resources
Featured Centers
Health Solutions From Our Sponsors
Health Solutions From Our Sponsors

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
FDA Prescribing Information.
Medscape. phenylephrine.