What’s the Difference Between Codeine and Promethazine Cough Syrup?

Promethazine and promethazine with codeine are cough suppressants that help to reduce or stop coughing due to allergies or colds. Please continue reading to get answers to some frequently asked questions about these medications, including dosage, possible side effects, and risks. We will also list some tips on the safe use of promethazine/codeine.

What is promethazine?

Promethazine (proe-meth-ah-zeen) belongs to a group of medications called phenothiazines. It is used to treat symptoms of the common cold, allergic reactions, and allergic conjunctivitis, such as a runny nose, sneezing, cough, and watery eyes. This medicine is also used to treat allergic skin reactions, provide sedation in patients undergoing surgical procedures, prevent and control nausea/vomiting after surgery, and prevent or treat motion sickness. Brand names for promethazine in the U.S. include Phenergan and Promacot.

Learn the difference between Spring Allergies Vs. A Cold.

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Is promethazine effective for cough?

Promethazine effectively reduces the frequency of or eliminates coughs due to colds and allergies. However, this medicine is used for symptomatic relief and will not treat infections. 

Is promethazine for dry or wet cough?

Promethazine with codeine is mainly used to treat dry cough. It is not generally used for cough with mucus (a form of “productive cough”), which is considered beneficial in infectious scenarios. 

Learn more: Wet Cough vs Dry Cough: What to Know

Is promethazine a narcotic?

Promethazine is not a narcotic. It is a phenothiazine and a type of antihistamine. Promethazine works by preventing the effects of histamine, a natural substance in the body created by immune cells that causes symptoms like sneezing, runny nose, coughing, and watery eyes. 

Does promethazine contain codeine?

As stated earlier, promethazine and codeine are separate medications. A combination of promethazine and codeine is available in syrup form. Common brand names of this liquid solution include Phenergan with Codeine and Pentazine with Codeine. This combination of two medications is a very effective cough suppressant. Promethazine is a phenothiazine that blocks the effects of histamine in the body to relieve cold and allergy symptoms, while codeine is an opioid medication used to relieve pain and suppress cough at certain dosages. 

How much codeine is in promethazine and codeine?

A 5 mL dose (1 teaspoonful) of promethazine/codeine syrup contains promethazine hydrochloride 6.25 mg and codeine phosphate 10 mg in a flavored syrup.

The dose of promethazine/codeine cough syrup for adults and children 12 years old and older is 5 mL (1 teaspoonful) every 4-6 hours as needed. Read the prescription label carefully and take this medicine exactly as directed. 

Do not take a higher dose or more frequent doses of promethazine/codeine than prescribed. You can take this medicine as needed rather than on a regular dosing schedule. Keep in mind that the maximum dose of promethazine/codeine is 30 mL (6 x 5 mL doses) in 24 hours. In case of a missed dose, take the next dose when needed.

Use a dose-measuring device such as a syringe or medication spoon to measure the dose of liquid medicine accurately. Using a household spoon is not recommended.

Promethazine/codeine is contraindicated for children younger than 12 years of age. This cough syrup is also contraindicated in children younger than 18 years of age following tonsillectomy or adenoidectomy. For adolescents 12 to 18 years of age, this codeine-containing cough syrup must also be avoided for those with existing risk factors that may increase the chance of respiratory depression. The best practice is always to consult your healthcare provider before giving this cough syrup to anyone 18 years old and younger. 

Read Next: What is a Safe Cough Medicine for Babies?

Can I take promethazine/codeine long-term?

Promethazine/codeine is not intended for long-term use. This medicine can be habit-forming with prolonged use and can cause serious side effects. If this promethazine/codeine syrup does not relieve the cough after 5 days, talk to your doctor. Do not take this medicine for longer than your doctor tells you to.

How long does it take for promethazine with codeine to start working?

Promethazine with codeine starts working within 30 minutes of taking a dose. The full effects of this medicine can be seen 1-2 hours after it is consumed. 

What are the side effects of promethazine with codeine cough syrup?

Possible side effects of promethazine with codeine include drowsiness, dizziness, difficulty concentrating, dry mouth, headache, nausea, vomiting, constipation, and sweating.

Other side effects of this medicine can be more serious. Contact your health care professional without delay if you notice any of the following symptoms while taking promethazine/codeine: 

• An unusual or allergic reaction

• Respiratory depression (decreased breathing)

• Difficulty breathing (short of breath) 

• Irregular heartbeat

• Fever

• Muscle stiffness

• Tremors

• Increased sweating

• Seizures

• Jaundice (yellowing of the skin and/or eyes) 

In case of an overdose, call your doctor immediately; if your doctor is not available right away, you should go to the nearest emergency room. The poison control center is a good resource for overdose symptoms, along with other useful information in case of an overdose. 

Check out Common Questions About Cough Medicine Safety and Side Effects.

What are the risks of taking promethazine and codeine cough syrup? 

Here are some of the risks of taking promethazine/codeine and some tips on the safe use of this medicine.

Habit-Forming and Risk of Overdose

Promethazine with codeine contains codeine, which is a narcotic (opioid) drug. It is designated as a Schedule V controlled substance and can be habit-forming with long-term use. This can happen even if you are taking the medicine at the prescribed doses. There is also a risk of opioid overdose and death. To reduce your risk, take promethazine with codeine at the dosage and duration recommended by your doctor.

Drug Misuse and Abuse

Codeine and promethazine cough syrup is sometimes abused by mixing it with Sprite or alcohol. This mixture has been popularly referred to as "purple drank" or "lean" and is popularized for its euphoric and tranquilizing effects. Never abuse or misuse prescription drugs, as this can put you at risk of very serious side effects. 

Breathing Problems

Promethazine/codeine affects breathing and can lead to potentially life-threatening respiratory depression. The risk is higher if you are taking other central nervous system (CNS) depressants like sleeping pills or have health conditions like sleep apnea or lung disease. Tell your doctor if you develop any difficulty breathing while on this medication.

Drowsiness and Dizziness

Taking promethazine/codeine can also cause extreme drowsiness and dizziness. These effects occur with greater intensity if you are taking other medicines that cause these effects, like benzodiazepines (Valium, Xanax). Drinking alcohol while on this medication can also worsen side effects. Tell your doctor if you experience any unusual or increased sleepiness while on this medicine. Do not drive, operate machinery, or do anything that requires your full concentration until you know how this medicine affects you.

Drug Interactions

Interactions between promethazine/codeine and certain medicines can lead to very serious side effects. Give your doctor and pharmacist a complete list of your medications, including prescription drugs, over-the-counter medications, herbal products, and dietary supplements, to reduce the risk of drug interactions. 

Pregnant Women

Promethazine/codeine is not safe for use during pregnancy. This medication can cause withdrawal symptoms in newborn babies because it contains an opioid (codeine). Talk to your doctor about safer treatment options for cough if you are pregnant or breastfeeding.

Neuroleptic Malignant Syndrome

In a small number of people, promethazine with codeine can cause a rare but life-threatening condition called neuroleptic malignant syndrome (NMS). Taking other drugs, specifically antipsychotic medications, can increase the risk of developing this complication. Symptoms of NMS include high fever, confusion, muscle stiffness, excessive sweating, and abnormal heart rate and blood pressure. Give your healthcare provider a complete list of your medications before starting promethazine/codeine. Seek immediate medical help if you experience any of the above symptoms.

Extrapyramidal Symptoms

Very rarely, taking promethazine/codeine can cause extrapyramidal symptoms (EPS), which are uncontrolled movements like tremors and jerks of the face, tongue, and other parts of the body. Tell your doctor or seek medical attention right away if you notice any unusual movements.

Other Medical Conditions

Promethazine/codeine should be used with caution or avoided in people with a history of certain medical conditions. Tell your doctor if you have a medical problem such as low blood pressure, heart problems, Addison’s disease (adrenal insufficiency), seizures, or low white blood cell count (for example, after undergoing chemotherapy).