ED A-Hist DM
ED A-Hist DM is a combination medication that contains chlorpheniramine (an antihistamine), dextromethorphan (a cough suppressant), and phenylephrine (a decongestant). It's an over-the-counter medication for adults and children to help treat allergy and common cold symptoms, like cough, stuffy or runny nose, and itchy or watery eyes. ED A-Hist DM is available as a tablet or liquid that's taken by mouth every 4 hours for symptom relief. This combination medication can also be found under several different brand names (for example, NoHist DM). Possible side effects include making you feel sleepy, restless, or dizzy and dry mouth.
What is ED A-Hist DM?
What is ED A-Hist DM used for?
Short-term relief of symptoms from allergies and the common cold:
Runny nose
Sneezing
Itchy nose or throat
Itchy, watery eyes
Cough from throat and lung irritation
Stuffy nose (nasal congestion)
How ED A-Hist DM works
ED A-Hist DM is a combination of three medications that work together to relieve symptoms caused by the common cold and allergies.
Chlorpheniramine is an antihistamine. It blocks histamine, a natural substance in your body that normally causes common cold and allergy symptoms. By blocking histamine, chlorpheniramine lowers inflammation (swelling) and relieves runny or itchy nose, sneezing, and watery eyes.
Dextromethorphan is a cough suppressant. It works in the brain to lower your urge to cough.
Phenylephrine is a decongestant that clears your sinuses to relieve sinus pressure.
Drug Facts
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What are the side effects of ED A-Hist DM?
Common Side Effects
- Sleepiness
- Restlessness
- Dizziness
- Dry mouth
Other Side Effects
- Headache
- Blurry vision
- Trouble urinating
Serious Side Effects
- Serotonin syndrome: fast heart rate, sweating, muscle stiffness or spasms, high fever, confusion
Source:Â DailyMed
The following side effects have also been reported
Side effects that you should report to your care team as soon as possible:
- Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
- Heart palpitations—rapid, pounding, or irregular heartbeat
- Increase in blood pressure
- Sudden eye pain or change in vision such as blurry vision, seeing halos around lights, vision loss
- Trouble passing urine
Side effects that usually do not require medical attention (report these to your care team if they continue or are bothersome):
- Anxiety, nervousness
- Confusion
- Constipation
- Dizziness
- Drowsiness
- Dry mouth
- Fatigue
Pros and cons of ED A-Hist DM
Pros
Can treat a wide variety of common cold or allergy symptoms
Conveniently combines three medications into one product
Available over the counter
Available as a tablets and an oral liquid
Cons
Might need to take as often as every 4 hours to relieve symptoms
More difficult to customize the dose since it's a fixed combination of three medications
Might not be the best choice for people over 65 years old; people with glaucoma; or people with heart, breathing, or urinary problems
Pharmacist tips for ED A-Hist DM
You can take ED A-Hist DM with or without food. If it upsets your stomach, try taking the medication with food.
If you're using a liquid form of ED A-Hist DM, use a medication dose cup or an oral syringe to measure your dose. Don't use household spoons because they aren't accurate and using them might cause you to take the wrong dose.
ED A-Hist DM can make you sleepy or dizzy, which can affect your ability to focus, think, or react. Don't drive until you know how the medication affects you. Taking the least amount of medication possible before bed can help lessen sleepiness and its effect on concentration during the daytime.
Limit or avoid alcohol while you're taking ED A-Hist DM. Alcohol can worsen side effects like sleepiness and dizziness.
It's possible for children who use ED A-Hist DM to become overly excited or energetic. Stop ED A-Hist DM and speak to a pediatrician if this happens to your child.
You can use ED A-Hist DM to temporarily relieve cold or allergy symptoms. But let your healthcare team know if your symptoms worsen or last longer than a week. Also tell them if you start to have a fever, rash, or headache. These might be signs that you need more medical attention.
Stop taking ED A-Hist DM and contact your healthcare team if you experience dizziness, nervousness, or trouble sleeping. These might be side effects from certain ingredients in ED A-Hist DM, such as phenylephrine. Depending on how bothersome these side effects are, your care team might recommend taking a lower dose of ED A-Hist DM or using a different option to relieve your symptoms.
Talk to a healthcare professional first before starting any new medications — especially other antihistamines, cough suppressants, or decongestants — while you're taking ED A-Hist DM. Taking certain medications with ED A-Hist DM can raise your risk for severe side effects, including seizures, hallucinations (seeing things that aren't real), high blood pressure, and fast heart rate.
Don't take ED A-Hist DM if you're currently taking or have taken a monoamine oxidase inhibitor (MAOI), such as selegiline or phenelzine (Nardil), in the last 2 weeks. This combination can raise your risk for severe side effects like serotonin syndrome and high blood pressure. Contact your primary care provider or pharmacist for other options to relieve your cough, congestion, and allergy symptoms.
Frequently asked questions about ED A-Hist DM
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What are the risks and warnings for ED A-Hist DM?
ED A-Hist DM can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
Sleepiness
Risk factors: Taking with alcohol | Taking other medications that cause drowsiness | 65 years or older
ED A-Hist DM commonly causes drowsiness. This can affect your ability to focus, think, and react. This side effect is more likely to happen or be more intense if you're over 65 years old. Drinking alcohol or taking ED A-Hist DM with other medications that cause drowsiness (e.g., opioids, benzodiazepines, sleep medications) can also worsen drowsiness. Be careful and avoid activities that require you to be alert, such as driving a car or operating machinery, until you know how ED A-Hist DM affects you.
Serotonin syndrome
Risk factors: Taking monoamine oxidase inhibitors (MAOI) 14 days before starting ED A-Hist DM | Taking other medications that raise serotonin levels in your brain
The dextromethorphan in ED A-Hist DM can raise your risk for serotonin syndrome. This is a rare, but potentially life-threatening side effect that happens when there's too much serotonin in the brain. Your risk is higher if you're also taking other medications that affect serotonin levels, such as certain antidepressants, MAOIs, and certain migraine medications.
Make sure your healthcare team knows about all the medications you take or plan to take (including over-the-counter medications and supplements) before starting ED A-Hist DM. Get medical help right away if you have any symptoms of serotonin syndrome, such as fast heart rate, sweating, muscle stiffness or spasms, high fever, and confusion.
Accidentally taking too much medication
ED A-Hist DM contains an antihistamine (chlorpheniramine), cough suppressant (dextromethorphan), and a decongestant (phenylephrine). These ingredients can be found in many other over-the-counter products for allergy, cough, and cold.
The risk of accidentally taking too much medication is higher if you use more than one product containing the same or similar ingredients. Tell your primary care provider or pharmacist about the medications you take before starting ED A-Hist DM. And don't start any new medications without talking to them first. Be sure to carefully read the package labels for its active ingredient list and dosing. Ask your pharmacist if you're not sure whether a product has any similar ingredients and whether it's safe for you.
Early signs that you might've accidentally taken too much medication can include confusion, not being aware of your surroundings, flushed or very warm skin, and vision changes. It can lead to serious side effects, such as anxiety or other behavior changes, high blood pressure, and trouble breathing. Get medical help right away or contact a Poison Control Center at 1-800-222-1222 if you or your loved one accidentally took too much medication.
Worsening of certain medical conditions
Risk factors: Heart disease or high blood pressure | Thyroid problems | High blood sugar (diabetes) | Glaucoma | Mucus-producing cough | Breathing problems (e.g., emphysema, long-term bronchitis) | Urinary conditions
Let your primary care provider and pharmacist know about all the medical conditions you have before you start taking ED A-Hist DM. Ask them whether this medication is safe for you to take.
ED A-Hist DM might worsen certain medical conditions, like heart disease, high blood pressure, glaucoma, and urination problems. There also might be a better option to treat your symptoms if you have a long-lasting cough with or without mucus, other breathing problems, thyroid problems, or diabetes.
ED A-Hist DM dosage forms
Typical dosing for ED A-Hist DM
Note: There are several manufacturers that make combination products containing chlorpheniramine, dextromethorphan, and phenylephrine. They each can have different amounts of medication and slightly different dosages. Check the medication label for the specific instructions for your product.
ED A-Hist DM tablets: Each tablet contains 4 mg of chlorpheniramine, 10 mg of dextromethorphan, and 10 mg of phenylephrine.
Adults and children 12 years or older: The typical dose is 1 tablet by mouth every 4 hours when you have symptoms. Don't take more than 6 tablets in a 24-hour period.
Children age 6 years to under 12 years old: The typical dose is one-half tablet by mouth every 4 hours when your child has symptoms. Don't take more than 3 tablets in a 24-hour period.
Children under 6 years old: Ask your child's pediatrician.
ED A-Hist DM liquid or NoHist DM liquid: Each 5 mL (1 teaspoonful) contains 4 mg of chlorpheniramine, 15 mg of dextromethorphan, and 10 mg of phenylephrine.
Adults and children 12 years or older: The typical dose is 1 teaspoonful (5 mL) by mouth every 4 hours when you have symptoms. Don't take more than 6 doses (30 mL) in a 24-hour period.
Children age 6 years to under 12 years old: The typical dose is one-half teaspoonful (2.5 mL) by mouth every 4 hours when your child has symptoms. Don't take more than 6 doses (15 mL) in a 24-hour period.
Children under 6 years old: Ask your child's pediatrician.
How much does ED A-Hist DM cost?
ED A-Hist DM contraindications
Currently take or have taken a monoamine oxidase inhibitor (MAOI) in the last 2 weeks
What are alternatives to ED A-Hist DM?
Short-term relief of symptoms from allergies and the common cold:
Runny nose
Sneezing
Itchy nose or throat
Itchy, watery eyes
Cough from throat and lung irritation
Stuffy nose (nasal congestion)
Cough from throat and lung irritation
Runny nose
Sneezing
Itchy or watery eyes
Itching of the nose or throat
Stuffy nose (nasal congestion)
Cough from throat and lung irritation
Runny nose
Sneezing
Itchy or watery eyes
Itching of the nose or throat
Stuffy nose (nasal congestion)
ED A-Hist DM images
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References
Best studies we foundBroderick, E. D., et al. (2023). Anticholinergic toxicity. StatPearls.
Edwards Pharmaceuticals, Inc. (2024). ED A-Hist DM- chlorpheniramine maleate, dextromethorphan hydrobromide, and phenylephrine hydrochloride tablet, coated [package insert]. DailyMed.
Edwards Pharmaceuticals, Inc. (2024). ED A-Hist DM- dextromethorphan hydrobromide, chlorpheniramine maleate, and phenylephrine hydrochloride liquid [package insert]. DailyMed.
Gelotte, C. K., et al. (2015). Pharmacokinetics, safety, and cardiovascular tolerability of phenylephrine HCl 10, 20, and 30 mg after a single oral administration in healthy volunteers. Clinical Drug Investigation.
Hoeft, D., et al. (2014). An overview of clinically significant drug interactions between medications used to treat psychiatric and medical conditions. Mental Health Clinician.
Larken Laboratories, Inc. (2023). Nohist DM- chlorpheniramine maleate, dextromethorphan hydrobromide and phenylephrine hydrochloride liquid [package insert]. DailyMed.
Oh, S., et al. (2023). Dextromethorphan. StatPearls.
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