Alahist DM

Generic name: brompheniramine, dextromethorphan, and phenylephrine [ brome-fen-IR-a-meen, dex-troe-meth-OR-fan, fen-il-EFF-rin ]
Brand names: Alahist DM, BP Allergy DM, Bromatan-DM, Children''s Cold & Cough DM, Cold & Cough Childrens, ... show all 12 brands Dimaphen DM, Dimetapp Cold & Cough, Dimetapp DM Cold & Cough, DuraTan DM, Rynex DM, TL-Hist DM, Tussi-Pres B
Drug class: Upper respiratory combinations

Medically reviewed by Drugs.com on May 27, 2022. Written by Cerner Multum.

What is Alahist DM?

Brompheniramine is an antihistamine that reduces the effects of the natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.

Dextromethorphan is a cough suppressant. It affects the signals in the brain that trigger cough reflex.

Phenylephrine is a decongestant that shrinks blood vessels in the nasal passages. Dilated blood vessels can cause nasal congestion (stuffy nose).

The combination of brompheniramine, dextromethorphan, and phenylephrine is used to treat runny or stuffy nose, sneezing, itching, watery eyes, cough, and sinus congestion caused by allergies, the common cold, or the flu.

Alahist DM will not treat a cough that is caused by smoking, asthma, or emphysema.

Alahist DM may also be used for purposes not listed in this medication guide.

Warnings

Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

You should not use this medication if you have severe constipation, a blockage in your stomach or intestines, or if you are unable to urinate.

Do not use this medication if you have untreated or uncontrolled diseases such as glaucoma, asthma or COPD, high blood pressure, heart disease, coronary artery disease, or overactive thyroid.

Do not use this medication if you have used an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.

Before taking this medicine

Do not use this medication if you have used an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.

You should not use Alahist DM if you have severe constipation, a blockage in your stomach or intestines, or if you are unable to urinate.

Do not use this medication if you have untreated or uncontrolled diseases such as glaucoma, asthma or COPD, high blood pressure, heart disease, coronary artery disease, or overactive thyroid.

Ask a doctor or pharmacist if it is safe for you to take this medication if you have:

• a colostomy or ileostomy;

• diabetes;

• liver or kidney disease;

• epilepsy or other seizure disorder;

• cough with mucus, or cough caused by emphysema or chronic bronchitis;

• enlarged prostate or urination problems;

• low blood pressure;

• pheochromocytoma (an adrenal gland tumor); or

• if you take potassium (Cytra, Epiklor, K-Lyte, K-Phos, Kaon, Klor-Con, Polycitra, Urocit-K).

FDA pregnancy category C. It is not known whether this medication will harm an unborn baby. Do not use Alahist DM without medical advice if you are pregnant.

This medicine may pass into breast milk and may harm a nursing baby. Antihistamines and decongestants may also slow breast milk production. Do not use this medicine without medical advice if you are breast-feeding a baby.

How should I take Alahist DM?

Use exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended. This medication is usually taken only for a short time until your symptoms clear up.

Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Do not take for longer than 7 days in a row. Talk with your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache or skin rash.

Measure liquid medicine with a special dose-measuring spoon or medicine cup, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist for one.

If you need surgery or medical tests, tell the surgeon or doctor ahead of time if you have taken a this medication within the past few days.

Store at room temperature away from moisture and heat. Do not freeze.

What happens if I miss a dose?

Since this medication is taken when needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

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

Overdose symptoms may include severe forms of some of the side effects listed in this medication guide.

What should I avoid while taking Alahist DM?

Alahist DM may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Drinking alcohol can increase certain side effects of this medication.

Ask a doctor or pharmacist before using any other cold, allergy, cough, or sleep medicine. Antihistamines, cough suppressants, and decongestants are contained in many combination medicines. Taking certain products together can cause you to get too much of a certain drug. Check the label to see if a medicine contains an antihistamine, cough suppressant, or decongestant.

Avoid taking this medication if you also take diet pills, caffeine pills, or other stimulants (such as ADHD medications). Taking a stimulant together with a decongestant can increase your risk of unpleasant side effects.

Avoid becoming overheated or dehydrated during exercise and in hot weather. This medication can decrease sweating and you may be more prone to heat stroke.

Alahist DM side effects

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

Stop using this medicine and call your doctor at once if you have a serious side effect such as:

• fast, slow, or uneven heart rate;

• severe headache, mood changes, hallucinations;

• severe dizziness or anxiety, feeling like you might pass out;

• tremor, seizure (convulsions);

• easy bruising or bleeding, unusual weakness;

• fever;

• urinating less than usual or not at all;

• feeling short of breath; or

• dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, uneven heartbeats, seizure).

Less serious side effects may include:

• mild headache;

• mild dizziness, drowsiness;

• dry mouth, nose, or throat;

• nausea, diarrhea, constipation, upset stomach;

• feeling nervous, restless, or irritable;

• blurred vision; or

• sleep problems (insomnia).

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 FDA at 1-800-FDA-1088.

What other drugs will affect Alahist DM?

Ask a doctor or pharmacist before using Alahist DM if you regularly use other medicines that make you sleepy (such as narcotic pain medication, sedatives, sleeping pills, muscle relaxers, and medicine for seizures, depression or anxiety). They can add to sleepiness caused by brompheniramine or dextromethorphan.

Ask a doctor or pharmacist if it is safe for you to take this medication if you are also using any of the following drugs:

• atropine (Atreza, Sal-Tropine);

• benztropine (Cogentin);

• topiramate (Topamax);

• zonisamide (Zonegran);

• an antidepressant such as citalopram (Celexa), duloxetine (Cymbalta), escitalopram (Lexapro), fluoxetine (Prozac, Sarafem, Symbyax), paroxetine (Paxil, Pexeva), sertraline (Zoloft), venlafaxine (Effexor), and others;

• anti-nausea medications such as belladonna (Donnatal), dimenhydrinate (Dramamine), droperidol (Inapsine), methscopolamine (Pamine), or scopolamine (Transderm Scop);

• bladder or urinary medications such as darifenacin (Enablex), flavoxate (Urispas), oxybutynin (Ditropan, Oxytrol), solifenacin (Vesicare), tolterodine (Detrol), or Urogesic Blue;

• bronchodilators such as ipratropium (Atrovent) or tiotropium (Spiriva);

• irritable bowel medications such as dicyclomine (Bentyl), hyoscyamine (Hyomax), or propantheline (Pro Banthine); or

• ulcer medicine such as glycopyrrolate (Robinul) or mepenzolate (Cantil).

This list is not complete and other drugs may interact with Alahist DM. Tell your doctor about all medications you use. This includes prescription, over-the-counter, vitamin, and herbal products. Do not start a new medication without telling your doctor.

Where can I get more information?

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

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