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A-Tan 12X Side Effects

Generic name: guaifenesin / phenylephrine / pyrilamine

Note: This document contains side effect information about guaifenesin / phenylephrine / pyrilamine. Some dosage forms listed on this page may not apply to the brand name A-Tan 12X.

Applies to guaifenesin/phenylephrine/pyrilamine: oral suspension, oral tablet.


Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Tell your doctor if you regularly use other medicines that make you sleepy (such as pain medication, sleeping pills, muscle relaxers, and medicine for seizures, depression or anxiety). They can add to sleepiness caused by pyrilamine.

Avoid drinking alcohol while you are taking this medication. Alcohol can add to drowsiness caused by an antihistamine.

Avoid taking diet pills, caffeine pills, or other stimulants (such as ADHD medications) without your doctor's advice. Taking a stimulant together with a decongestant can increase your risk of unpleasant side effects.

Do not use any other over-the-counter cough, cold, allergy, or sleep medication without first asking your doctor or pharmacist. If you take certain products together you may accidentally take too much of one or more types of medicine. Read the label of any other medicine you are using to see if it contains guaifenesin, phenylephrine, or pyrilamine.

Get emergency medical help if you have any of these signs of an allergic reaction while taking guaifenesin / phenylephrine / pyrilamine: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using this medication and call your doctor at once if you have any of these serious side effects:

Less serious side effects of guaifenesin / phenylephrine / pyrilamine may include:

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

For Healthcare Professionals

Applies to guaifenesin / phenylephrine / pyrilamine: oral suspension, oral tablet.

Nervous system

Nervous system side effects have included nervousness, restlessness, headache, drowsiness, and sedation.[Ref]


Gastrointestinal side effects have included nausea and vomiting.[Ref]


Dermatologic side effects have included rash, in addition to urticaria.[Ref]


General side effects have included dryness of mucous membranes.[Ref]

More about A-Tan 12X (guaifenesin / phenylephrine / pyrilamine)

Related treatment guides


1. Product Information. Ryna-12X (guaifenesin / phenylephrine / pyrilamine). Meda AB. 2003.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.