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Guaifenesin / hydrocodone / phenylephrine Side Effects

Applies to guaifenesin / hydrocodone / phenylephrine: oral elixir, oral liquid, oral syrup

MISUSE OF THIS MEDICINE CAN CAUSE ADDICTION, OVERDOSE, OR DEATH. Keep the medication in a place where others cannot get to it.

Fatal side effects can occur if you use this medicine with alcohol, or with other drugs that cause drowsiness or slow your breathing.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

This medicine can slow or stop your breathing, and death may occur. A person caring for you should seek emergency medical attention if you have slow breathing with long pauses, blue colored lips, or if you are hard to wake up.

Stop taking this medicine and call your doctor at once if you have:

  • noisy breathing, sighing, shallow breathing;

  • extreme drowsiness, confusion, feeling weak or limp;

  • a seizure;

  • a light-headed feeling, like you might pass out;

  • severe constipation;

  • little or no urination; or

  • adrenal gland problems--nausea, vomiting, loss of appetite, dizziness, worsening tiredness or weakness.

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Serious side effects may be more likely in older adults and those who are overweight, malnourished, or debilitated.

Long-term use of opioid medication may affect fertility (ability to have children) in men or women. It is not known whether opioid effects on fertility are permanent.

Common side effects may include:

  • drowsiness, dizziness;

  • lack of energy, coordination problems;

  • headache, confusion;

  • dry mouth, nausea, vomiting, constipation;

  • tremors, fast or irregular heart rate; or

  • feeling anxious, restless, nervous, or irritable.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

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.

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