Antitussive/antihistamine/decongestant/expectorant (By mouth)


Treats cough and congestion.

Brand Name(s)

G-P-Tuss DXP

When This Medicine Should Not Be Used

How to Use This Medicine

Liquid, Tablet, Capsule, Long Acting Tablet

  • Your doctor will tell you how much medicine to use. Do not use more than directed.
  • Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.
  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.
  • This medicine is not for long-term use.

If a dose is missed:

  • Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep all medicine out of the reach of children. Never share your medicine with anyone.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Tell your doctor if you use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.
  • Make sure your doctor knows if you are using indomethacin (Indocin®) or methyldopa (Aldomet®). Tell your doctor if you are using a beta-blocker medicine such as atenolol, metoprolol (Toprol®), or propranolol (Inderal®). Beta-blocker medicines are often used to treat migraines, heart problems, or high blood pressure.
  • Make sure your doctor knows if you are using medicine to treat depression, such as amitriptyline, doxepin, or nortriptyline. Tell your doctor if you are taking phenothiazine medicine such as prochlorperazine (Compazine®), Mellaril®, Phenergan®, or Thorazine®. Phenothiazine medicine may be used to treat severe vomiting, psychiatric problems, or other conditions.
  • There are many other drugs that may interact with this type of medicine. Make sure your doctor knows about all other medicines you are using.
  • Do not drink alcohol while you are using this medicine.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breast feeding.
  • Make sure your doctor knows if you have diabetes, thyroid problems, high blood pressure, heart disease, or heart rhythm problems. Tell your doctor if you have a history of allergies, kidney problems, liver problems, Addison's disease, asthma, or serious lung disease such as emphysema (COPD). Tell your doctor if you have a brain tumor, recent head injury, or a medical condition that causes increased pressure in your head (such as hydrocephalus). Make sure your doctor knows if you have prostate problems, or a narrowing or blockage of your digestive tract or urinary tract.
  • Make sure your doctor knows if you have had an allergic reaction to phenylephrine, brompheniramine, dextromethorphan, chlorpheniramine (Chlor-Trimeton®), guiafenesin, or to any antihistamine, cough medicine, cold or allergy medicine, or decongestant. Tell your doctor if you cannot use medicine that contains alcohol.
  • This medicine may contain phenylalanine. Make sure your doctor knows if you have phenylketonuria (PKU).
  • This medicine may hide the warning signs of certain serious medical conditions. Do not use this medicine for a chronic (long-term) cough unless your doctor tells you to.
  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Confusion, hallucinations (seeing things that are not there), seizures, or fainting.
  • Heartbeat that is pounding or uneven.
  • New or worsening fever.
  • Sudden or severe headache.
  • Trouble urinating, or feeling like you have a full bladder even after you urinate.
  • Unusual bleeding, bruising, or weakness.

If you notice these less serious side effects, talk with your doctor:

  • Anxiety, trouble sleeping, or other mood changes that are bothersome to you.
  • Lightheadedness, blurred vision, or eyes sensitive to light.
  • Cough that lasts more than one week, that comes back often, or that happens with a fever, rash, or headache.
  • Nausea that does not go away after you lie down.
  • Tremors (shaking) or problems with balance or coordination.
  • Vomiting, stomach upset, dry mouth, or constipation.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 10/4/2017

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