Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes Sinex (Oxymetazoline-nasal). If you are concerned about side effects, discuss the risks and benefits of Sinex (Oxymetazoline-nasal) with your doctor.

The following side effects have been reported by at least 1% of people taking Sinex (Oxymetazoline-nasal). Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• burning and stinging of the nose
• dryness of the nose
• headache
• increased nasal discharge
• sneezing
• trouble sleeping

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• blurred vision
• dizziness or lightheadedness
• drowsiness
• high blood pressure
• nervousness
• palpitations (heartbeat that is fast, irregular, or pounding)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of too much medication (CNS Depression; e.g., slurred speech, unclear thinking, blurred vision, decreased coordination, decreased sensitivity to pain, or sleepiness)
• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking Sinex (Oxymetazoline-nasal).

Sinex (Oxymetazoline-nasal) is available as a nasal spray.

Do not use Sinex (Oxymetazoline-nasal) if you:

• are allergic to oxymetazoline or any ingredients of Sinex (Oxymetazoline-nasal)
• are currently taking monoamine oxidase (MAO) inhibitors (e.g., Phenelzine, Tranylcypromine)
• are sensitive (i.e., experience trouble sleeping, dizziness, lightheadedness, weakness, tremor, or abnormal heart rhythms) to other related medications (e.g., Epinephrine, phenylephrine, Pseudoephedrine)
• have narrow-angle Glaucoma
• have rhinitis sicca (a chronic type of rhinitis with very little or no nasal discharge)

There may be an interaction between oxymetazoline nasal spray and any of the following:

• alpha blockers (e.g., Alfuzosin, Doxazosin, Tamsulosin)
• amphetamines (e.g., Dextroamphetamine, Lisdexamfetamine)
• Atomoxetine
• Bromocriptine
• caffeine
• cannabis
• dipivefrin
• dobutamine
• dopamine
• dronabinol
• epinephrine
• ergot alkaloids (e.g., Dihydroergotamine, ergonovine, ergotamine, methylergonovine)
• fast-acting bronchodilators (e.g., salbutamol, terbutaline)
• Fentanyl
• Linezolid
• long-acting bronchodilators (e.g., formoterol, salmeterol)
• Methylphenidate
• monoamine oxidase inhibitors (M.O.S. e.g., Moclobemide, phenelzine, Rasagiline, Selegiline, tranylcypromine)
• Nabilone
• norepinephrine
• other decongestant cold medications (e.g., phenylephrine, pseudoephedrine)
• other decongestant eye drops and nose sprays (e.g., naphazoline, xylometazoline)
• theophyllines  (e.g., Aminophylline, Oxtriphylline, Theophylline)
• tricyclic antidepressants (e.g., Amitriptyline, Nortriptyline, Desipramine)

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with Sinex (Oxymetazoline-nasal). Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the Nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use Sinex (Oxymetazoline-nasal).

Medical conditions: If you have difficulty urinating because of an enlarged prostate, heart disease, high blood pressure, glaucoma, overactive Thyroid, advanced hardening of the arteries, or Diabetes, discuss with your doctor how Sinex (Oxymetazoline-nasal) may affect your medical condition, how your medical condition may affect the dosing and effectiveness of Sinex (Oxymetazoline-nasal), and whether any special monitoring is needed.

Prolonged or excessive use: Do not use Sinex (Oxymetazoline-nasal) for more than 3 days. Using Sinex (Oxymetazoline-nasal) for longer than 3 days may cause your congestion to worsen when you stop using the medication. Do not use more than the recommended dose. Excessive use can increase the risk of side effects, especially for children.

Spread of infection: Use of this nasal spray by more than one person may cause spread of infection.

Pregnancy: Sinex (Oxymetazoline-nasal) should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking Sinex (Oxymetazoline-nasal), contact your doctor immediately.

Breast-feeding: It is not known if oxymetazoline passes into breast milk. If you are a breast-feeding mother and are using this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using Sinex (Oxymetazoline-nasal) have not been established for children under 12 years of age.