A-Tan 12X Side Effects

Generic Name: guaifenesin / phenylephrine / pyrilamine

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

Not all side effects for A-Tan 12X may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

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

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:

  • fast, pounding, or uneven heartbeat;

  • severe dizziness, anxiety, restless feeling, or nervousness;

  • easy bruising or bleeding, unusual weakness, fever, chills, body aches, flu symptoms;

  • increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure); or

  • nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

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

  • blurred vision;

  • dry mouth;

  • dizziness, drowsiness, headache;

  • problems with memory or concentration;

  • ringing in your ears;

  • restless or excitability (especially in children);

  • warmth, tingling, or redness under your skin;

  • sleep problems (insomnia);

  • skin rash or itching; or

  • mild nausea, stomach pain, constipation.

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.


Gastrointestinal side effects have included nausea and vomiting.


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


General side effects have included dryness of mucous membranes.

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

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