Note: This document contains side effect information about oxymetazoline nasal. Some dosage forms listed on this page may not apply to the brand name Neo-Synephrine 12 Hour.

Applies to oxymetazoline nasal: nasal spray.

Serious side effects

Along with its needed effects, oxymetazoline nasal (the active ingredient contained in Neo-Synephrine 12 Hour) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking oxymetazoline nasal:

• Blurred vision
• fast, irregular, or pounding heartbeat
• headache, dizziness, drowsiness, or lightheadedness
• high blood pressure
• increase in runny or stuffy nose
• nervousness
• trembling
• trouble in sleeping
• weakness

Other side effects

Some side effects of oxymetazoline nasal may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

• Burning, dryness, or stinging inside of nose
• sneezing

For Healthcare Professionals

Applies to oxymetazoline nasal: nasal solution, nasal spray.

Cardiovascular

Very rare (less than 0.01%): Tachycardia, palpitations, increased blood pressure^[Ref]

Gastrointestinal

Very rare (less than 0.01%): Nausea^[Ref]

General

The most commonly reported side effects were discomfort or irritation in the nose, mouth or throat, and sneezing.^[Ref]

Nervous system

Very rare (less than 0.01%): Insomnia, nervousness, tremor, anxiety, restlessness, irritability, headache^[Ref]

Ocular

Rare (less than 0.1%): Eye irritation, dryness, discomfort/redness^[Ref]

Respiratory

Rare (less than 0.1%): Discomfort or irritation in the nose, mouth or throat, sneezing

Frequency not reported: Rhinitis medicamentosa (after prolonged or heavy use)^[Ref]