Promethazine DM is a combination medication containing the drugs promethazine and dextromethorphan. It is used to treat coughs caused by the common cold, allergies, or respiratory infections. Promethazine is an antihistamine that helps reduce symptoms like runny nose, sneezing, and watery eyes. Dextromethorphan is a cough suppressant that helps control coughing. Promethazine DM is available over-the-counter without a prescription. When used as directed, it can provide quick relief for annoying cough symptoms.
What are the ingredients in Promethazine DM?
Promethazine DM contains two active ingredients:
- Promethazine: This is an antihistamine that blocks the effects of histamine, a chemical in the body that causes allergy symptoms. It can help relieve runny nose, sneezing, watery eyes, and other allergy or cold symptoms.
- Dextromethorphan (DM): This is a cough suppressant that works in the brain to block the cough reflex. It can provide temporary relief for coughing caused by minor throat and bronchial irritation.
In addition to the active ingredients, Promethazine DM also contains inactive ingredients like flavorings, preservatives, and dyes. The specific inactive ingredients may vary between products and brands.
How does Promethazine DM work?
Promethazine DM relieves coughs through the combined effects of its active ingredients:
- Promethazine blocks histamine receptors and prevents histamine from binding to cells. This stops allergy symptoms like runny nose, sneezing, and watery eyes from occurring.
- Dextromethorphan acts on cough receptors in the brain and spinal cord. It prevents nerve signals from triggering the cough reflex.
Together, these medications target the underlying causes of cough – allergies and overactive cough reflexes. Promethazine controls allergy symptoms while dextromethorphan suppresses the urge to cough. This provides more complete cough relief.
What is Promethazine DM used for?
Promethazine DM is approved for use in adults and children over 6 years old. It can be used to treat coughs caused by:
- Colds
- Allergies
- Flu
- Sinus infections
- Bronchitis
Promethazine DM is intended for temporary relief of annoying but not severe coughs. It will not treat infections or medical conditions causing chronic coughs. But it can control coughing episodes so that the underlying condition has time to improve.
What are the benefits of Promethazine DM for cough?
Some key benefits of using Promethazine DM for cough relief include:
- Combination medication – Contains an antihistamine and a cough suppressant for more complete relief.
- Works quickly – Starts relieving coughs within 30 minutes.
- Long-lasting – Effects can last up to 12 hours with one dose.
- Convenient dosing – Typically taken every 12 hours as needed.
- Over-the-counter – Available without a prescription.
- Low risk of drowsiness – Unlike some OTC cough medicines.
For annoying coughs that disrupt sleep or daily activities, Promethazine DM can provide fast-acting and long-lasting relief without sedative side effects.
How do you take Promethazine DM?
Promethazine DM comes as tablets, capsules, or liquid forms. The recommended dosage depends on age:
| Age | Dosage |
|---|---|
| Adults and children over 12 | 1 tablet, capsule, or 10mL of liquid every 12 hours |
| Children 6-12 years | 1/2 tablet, capsule, or 5mL of liquid every 12 hours |
Promethazine DM should be taken every 12 hours as needed for cough. It is not intended for continuous daily use. Follow dosage directions carefully and do not take more than prescribed amounts.
Promethazine DM can be taken with or without food. Drink plenty of fluids when taking it to help thin mucus and avoid dehydration. Avoid alcohol while taking Promethazine DM as it can increase drowsiness.
How long does Promethazine DM take to work?
Promethazine DM typically begins working within 30 minutes after taking a dose. You may notice cough suppression and relief from allergy symptoms like runny nose and sneezing during this time.
The maximum effects occur after about 2-3 hours. Relief can last up to 12 hours with one dose. If cough symptoms return, another dose can be taken after 12 hours.
You may need to take Promethazine DM for a few days in a row until the underlying cause of the cough improves. Continue taking it as directed for lasting relief.
What are the side effects of Promethazine DM?
Possible side effects of Promethazine DM include:
- Drowsiness
- Dizziness
- Dry mouth
- Nausea
- Constipation
- Blurry vision
These tend to be mild and short-lived. Drowsiness is less common than with some other cough and cold medications. Seek medical help if you experience severe or concerning side effects.
Who should not take Promethazine DM?
People who should avoid Promethazine DM include:
- Children under 6 years old
- Those with severe coughs like pneumonia, bronchitis, or asthma
- People taking antidepressants called MAO inhibitors
- Those allergic or sensitive to promethazine, dextromethorphan, or similar drugs
- People with difficulty urinating due to prostate enlargement
- Women who are pregnant or breastfeeding
Talk to your doctor before taking Promethazine DM if you have glaucoma, heart disease, high blood pressure, liver or kidney disease, seizures, sleep apnea, or breathing issues.
Is Promethazine DM safe during pregnancy and breastfeeding?
Promethazine DM has not been proven safe for use during pregnancy or breastfeeding. Promethazine can cross the placenta and enter breastmilk. The effects on unborn babies and nursing infants are unknown.
Pregnant and breastfeeding women should always consult their doctor first before taking any medications, including over-the-counter cough remedies. Safer alternative treatments may be recommended instead.
Can you take Promethazine DM with other medications?
Promethazine DM can interact with other drugs, including:
- Antidepressants like MAO inhibitors
- Pain medicines like codeine
- Anxiety/sleep medications
- Other antihistamines
The combination can increase side effects like drowsiness, dizziness, and breathing problems in some cases. Tell your doctor about all medications you take before starting Promethazine DM.
How long is Promethazine DM effective for coughs?
Promethazine DM is intended for temporary relief of coughs caused by colds, allergies, and other respiratory illnesses. It can suppress coughing for up to 12 hours with each dose.
However, it does not treat the underlying infection or illness causing the cough. It should not be used for more than a few days in a row. Talk to your doctor if cough persists more than one week or returns after stopping Promethazine DM.
What are alternatives to Promethazine DM for cough?
Some over-the-counter alternatives for cough relief include:
- Cough syrups with dextromethorphan or guaifenesin
- Cough drops or lozenges
- Humidifier to moisten airways
- Salt water gargles
- Honey or peppermint tea
- Nasal saline spray for congestion
For chronic coughs, prescription medications may be required. Talk to your doctor if OTC remedies do not provide enough relief.
What if Promethazine DM is not working for cough?
If Promethazine DM is not effective for cough relief, possible reasons include:
- Incorrect condition – It won’t help coughs from COPD, bronchitis, pneumonia, etc.
- Insufficient dose – Make sure to take the recommended amount.
- Severe cough – May need prescription medication for very bad coughs.
- Other medical issue – See a doctor to check for underlying illness.
- Drug interactions – Other medications may affect how it works.
Talk to a doctor if your cough persists more than one week while taking Promethazine DM as directed. An undiagnosed medical problem could require different treatment.
Can you overdose on Promethazine DM?
Yes, it is possible to overdose on Promethazine DM by exceeding the recommended dosages. Overdose can result in severe drowsiness, confusion, irritability, muscle twitching, ringing in the ears, nausea, vomiting, and breathing problems.
Never take more Promethazine DM than prescribed or double up doses. An overdose requires emergency medical treatment. Call 911 or poison control if you suspect an overdose.
How long does a dose of Promethazine DM last?
A dose of Promethazine DM typically provides cough relief for about 12 hours. You may begin feeling effects within 30 minutes that peak after 2-3 hours. The cough-suppressing and antihistamine effects diminish over the 12 hour period.
Take Promethazine DM every 12 hours as needed, but do not exceed dosing recommendations. Taking it too often can cause side effects or overdose. Follow your doctor’s instructions carefully.
Conclusion
Promethazine DM is an effective over-the-counter remedy for temporarily relieving coughs caused by colds, allergies, and other respiratory tract infections. The combination of promethazine and dextromethorphan works to control allergy symptoms and suppress the urge to cough. When used as directed, Promethazine DM can provide fast-acting, long-lasting cough relief without sedative side effects.
However, Promethazine DM only treats the symptom of coughing itself, not any underlying illnesses. Seek medical advice if coughs persist more than one week or return shortly after stopping. With proper use for appropriate conditions, Promethazine DM can be a helpful option for quieting annoying but not chronic coughs.
