Pseudoephedrine belongs to a group of medications called decongestants. It is used to temporarily relieve symptoms of nasal or sinus congestion that occur with allergies, sinusitis, ear infections, and the common cold. Pseudoephedrine works by causing the blood vessels in the sinuses to tighten, decreasing the swelling of the sinuses and making it easier to breathe.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

Decongestant 12-hour caplets: The usual recommended dose for adults and children 12 years of age and older is one tablet every 12 hours. Do not take more than 2 doses per day.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is important to take this medication exactly as prescribed by your doctor. Do not use higher doses than those recommended by your doctor.

If you are using this medication regularly and you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not take this medication if you:

• are allergic to pseudoephedrine or any ingredients of this medication
• have taken monoamine oxidase (MAO) inhibitors within 14 days or intend to take such a medication in the next 14 days
• have severe high blood pressure, or severe coronary artery disease

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 this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. 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.

• confusion
• difficulty passing urine
• dizziness or lightheadedness
• dry mouth
• fast pounding heartbeat (palpitations)
• hand tremor
• headache
• increased wakefulness
• muscle weakness
• nausea or vomiting
• nervousness
• restlessness
• tightness in the chest
• 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 seek medical attention.

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

• convulsions
• hallucinations
• irregular fast or slow heartbeat
• shortness of breath or troubled breathing
• skin eruptions (e.g., rash or hives)

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 this medication.

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 this medication.

Liver or kidney disease: If you have kidney or liver disease you may need a lower dose of this medication.

Other medical conditions: Decongestants such as pseudoephedrine should be used with caution if you have:

• diabetes
• enlarged prostate
• glaucoma
• heart disease
• high blood pressure
• high intraocular (inside the eye) pressure
• overactive thyroid
• kidney disease
• stomach ulcers

Pregnancy and breast-feeding: It is not known whether this medication is safe to use during pregnancy and breast-feeding. It should not be used during pregnancy or breast-feeding unless the benefits outweigh the risks.

Seniors: Seniors should use this medication with caution, as they are more likely to experience side effects.

There may be an interaction between pseudoephedrine and any of the following:

• appetite suppressants
• blood pressure medications
• certain antidepressants
• MAO inhibitors (e.g., phenelzine, tranylcypromine)
• other decongestants
• stimulants (e.g., methylphenidate, dextroamphetamine)

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 this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications 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.