Font Size

Medications and Drugs

Brand Names: Maxiphen CD, Maxiphen CDX

Generic Name: codeine, guaifenesin, and phenylephrine (Pronunciation: KOE deen, gwye FEN e sin, FEN il EFF rin)

What is codeine, guaifenesin, and phenylephrine (Maxiphen CD, Maxiphen CDX)?

Codeine is in a group of drugs called narcotics. It is a cough suppressant that affects the signals in the brain that trigger cough reflex.

Guaifenesin is an expectorant. It helps loosen mucus congestion in your chest and throat, making it easier to cough out through your mouth.

Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

The combination of codeine, guaifenesin, and phenylephrine is used to treat cough, nasal, and sinus congestion, and to reduce chest congestion caused by upper respiratory infections or the common cold.

Codeine, guaifenesin, and phenylephrine may also be used for purposes other than those listed in this medication guide.

What are the possible side effects of codeine, guaifenesin, and phenylephrine (Maxiphen CD, Maxiphen CDX)?

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

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

  • severe dizziness, anxiety, restless feeling, or nervousness, tremors;
  • confusion, hallucinations, unusual thoughts or behavior;
  • seizure (convulsions);
  • fast, pounding, or uneven heartbeat;
  • slow heart rate, weak pulse, fainting, weak or shallow breathing; or
  • increased blood pressure (severe headache, blurred vision, trouble concentrating, chest pain, numbness, seizure).

Less serious side effects include:

  • dizziness, drowsiness, headache;
  • nausea, vomiting;
  • constipation;
  • feeling excited or restless;
  • sleep problems (insomnia);
  • warmth, tingling, or redness under your skin; or
  • skin rash or itching.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about codeine, guaifenesin, and phenylephrine (Maxiphen CD, Maxiphen CDX)?

Do not take this medication if you have used an MAO inhibitor such as isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam), or tranylcypromine (Parnate) within the past 14 days. Serious, life-threatening side effects can occur if you take cough or cold medicine before the MAO inhibitor has cleared from your body.

Do not use any other over-the-counter cough or cold 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 or phenylephrine.

Codeine may be habit-forming and should be used only by the person it was prescribed for. This medication should never be shared with another person, especially someone who has a history of drug abuse or addiction. Keep the medication in a secure place where others cannot get to it.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Pill Identifier Tool

Need help identifying pills and medications?
Use the pill finder tool on RxList.