diphenhydramine and phenylephrine

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Pronunciation: DYE fen HYE dra meenand FEN il EFF rin

Brand: Aldex-CT, Benadryl-D Children's Allergy & Sinus, Children's Triacting Night Time, Dimetapp Nighttime Cold & Congestion, Dytan-D, PediaCare Children's Allergy & Cold, Robitussin Night Time Cough & Cold

What is the most important information I should know about diphenhydramine and phenylephrine?

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, rasagiline, selegiline, tranylcypromine, and others.

What is diphenhydramine and phenylephrine?

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

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

Diphenhydramine and phenylephrine is a combination medicine used to treat symptoms of the common cold or seasonal allergies, including sneezing, runny or stuffy nose, and itchy, watery eyes.

Diphenhydramine and phenylephrine may also be used for purposes not listed in this medication guide.

What should I discuss with my healthcare provider before taking diphenhydramine and phenylephrine?

You should not use this medication if you are allergic to diphenhydramine or phenylephrine.

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, rasagiline, selegiline, tranylcypromine, and others.

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

  • asthma or COPD, cough with mucus, or cough caused by smoking, emphysema, or chronic bronchitis;
  • a blockage in your stomach or intestines;
  • kidney or liver disease;
  • high blood pressure, heart disease, coronary artery disease, or recent heart attack;
  • enlarged prostate or urination problems;
  • glaucoma;
  • diabetes;
  • epilepsy or other seizure disorder;
  • pheochromocytoma (an adrenal gland tumor);
  • overactive thyroid; 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 diphenhydramine and phenylephrine will harm an unborn baby. Do not use this medicine without your doctor's advice if you are pregnant.

It is not known whether diphenhydramine and phenylephrine passes into breast milk or if it could harm a nursing baby. Antihistamines and decongestants may also slow breast milk production. Do not use this medicine without your doctor's advice if you are breast-feeding a baby.

Older adults may be more likely to have side effects from this medicine.

Artificially sweetened liquid cold medicine may contain phenylalanine. If you have phenylketonuria (PKU), check the medication label to see if the product contains phenylalanine.

How should I take diphenhydramine and phenylephrine?

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. Cold medicine 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.

The chewable tablet must be chewed before you swallow it.

You make need to shake the liquid medicine well just before you measure a dose.

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.

Call your doctor if your symptoms do not improve after 7 days of treatment, or if you have a fever with a headache, cough, or skin rash.

If you need surgery, tell the surgeon ahead of time if you have taken a cold medicine within the past few days.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Since cold medicine is taken as 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.

What should I avoid while taking diphenhydramine and phenylephrine?

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Drinking alcohol can increase certain side effects of diphenhydramine and phenylephrine.

Ask a doctor or pharmacist before using any other cold, allergy, or sleep medicine. Diphenhydramine and phenylephrine 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 or decongestant.

What are the possible side effects of diphenhydramine and phenylephrine?

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

Stop using this medicine and call your doctor at once if you have:

  • a light-headed feeling, like you might pass out;
  • pounding heartbeats or fluttering in your chest;
  • easy bruising, unusual or bleeding, pale or yellowed skin, dark colored urine;
  • sudden weakness or ill feeling, fever, chills, red or swollen gums, confusion or weakness;
  • seizure (convulsions);
  • confusion, feelings of extreme happiness;
  • painful or difficult urination;
  • little or no urinating; or
  • dangerously high blood pressure (severe headache, buzzing in your ears, anxiety, shortness of breath).

Common side effects may include:

  • dizziness, drowsiness, loss of coordination;
  • feeling nervous, excited, or irritable;
  • sleep problems (insomnia);
  • increased sweating, numbness or tingly feeling;
  • blurred vision, dry mouth; or
  • nausea, vomiting, constipation, loss of appetite.

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 diphenhydramine and phenylephrine?

Ask a doctor or pharmacist before using this medicine if you are also using any other drugs, including prescription and over-the-counter medicines, vitamins, and herbal products. Some medicines can cause unwanted or dangerous effects when used together. Not all possible interactions are listed in this medication guide.

Taking this medicine with other drugs that make you sleepy or slow your breathing can worsen these effects. Ask your doctor before taking diphenhydramine and phenylephrine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Where can I get more information?

Your pharmacist can provide more information about diphenhydramine and phenylephrine.

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.

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