Dextromethorphan and promethazine

Dextromethorphan is a medicine that helps stop coughing. Promethazine is a medicine that helps with allergy symptoms.

Dextromethorphan and promethazine is a combination medicine used to treat cough, stuffy nose, runny nose, and sneezing caused by colds or allergies.

Dextromethorphan and promethazine can be used by adults and children who are at least 2 years old.

Dextromethorphan and promethazine may also be used for other reasons that are not mentioned in this medication guide.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Do not use dextromethorphan and promethazine in a child younger than 2 years old, and carefully follow all dosing directions for a child 2 years or older. Promethazine can slow the breathing, which has caused death in very young children.

Measure liquid medicine with the supplied syringe or a dose-measuring device (not a kitchen spoon).

This medicine can affect the results of certain medical tests and may cause false results on a pregnancy test. Tell the doctor or laboratory staff if you have taken dextromethorphan and promethazine in the past few days.

Call your doctor if your symptoms do not improve or if they get worse.

Store at room temperature away from moisture and heat. Keep the bottle tightly closed when not in use.

Promethazine can slow down breathing, which has led to death in very young children. Do not use dextromethorphan and promethazine in a child younger than 2 years old. Follow all instructions when giving the medicine to a child aged 2 years or older.

Do not use dextromethorphan and promethazine if you have taken an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.

You should not use this medicine if you are allergic to dextromethorphan or promethazine, or if you have:

• asthma or other breathing problems; or
• an allergy to medicines similar to promethazine (chlorpromazine, fluphenazine, prochlorperazine, thioridazine, and others).

Do not use this medicine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, tranylcypromine, and others.

Tell your doctor if you have ever had:

• chronic obstructive pulmonary disease (COPD), sleep apnea, or other breathing disorder;
• a seizure;
• eczema;
• bone marrow depression;
• glaucoma;
• a stomach ulcer;
• blockage in your stomach or intestines;
• a bladder obstruction or other urination problems;
• an enlarged prostate;
• liver disease;
• heart problems; or
• if you are on bed rest or otherwise debilitated.

Tell your doctor if you are pregnant or breastfeeding.

Taking this medicine during the last 2 weeks of pregnancy may increase the risk of bleeding in the newborn baby.

Ask a doctor before giving this medicine to a child younger than 12 years old.

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

This medicine may cause serious side effects. Stop using this medicine and call your doctor right away if you experience:

• weak or shallow breathing, or if your breathing stops during sleep;
• unusual restlessness or excitement;
• uncontrolled muscle movements in your neck, tongue, or eyes;
• fast, slow, or uneven heart rate;
• hallucinations or ringing in your ears;
• a seizure;
• fever, chills, or weakness;
• easy bruising or unusual bleeding;
• yellowing of your skin or eyes; or
• a severe nervous system reaction, which includes very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, or feeling faint.

Common side effects of dextromethorphan and promethazine may include:

• drowsiness or dizziness;
• dry mouth, nose, or throat;
• blurred vision;
• nausea or vomiting; or
• loss of coordination.

This is not a complete list of side effects, and others may occur. Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Dextromethorphan and promethazine is used as needed. If you have a dosing schedule and miss a dose, skip it. Do not take two doses at once.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include overactive reflexes, feeling restless or confused, slow breathing, dilated pupils, or fainting.

Avoid driving, riding a bike, or any other hazardous activity until you know how dextromethorphan and promethazine will affect you. Your reactions could be impaired.

Ask a doctor or pharmacist before using other cough or cold medicines that may contain dextromethorphan.

Avoid drinking alcohol.

Avoid sunlight, and wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Using dextromethorphan and promethazine with other medicines that make you sleepy can increase this effect. Talk to your doctor before using opioid medication, a sleeping pill, a muscle relaxer, or medicine for anxiety or seizures.

Inform your doctor about all your other medicines, especially:

• an antidepressant;
• a barbiturate like phenobarbital;
• bronchodilator asthma medication;
• cold or allergy medicine (like Benadryl);
• medicine for Parkinson's disease;
• medicine for overactive bladder; or
• medicine for stomach issues, motion sickness, or irritable bowel syndrome.

This list is not complete. Other drugs may affect dextromethorphan and promethazine, including both prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are included here.