diphenhydramine and pseudoephedrine

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Pronunciation: DYE fen HYE dra meen and SOO doe ee FED rin

Brand: Tavist NightTime Allergy

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

Do not use diphenhydramine and pseudoephedrine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

You should not use antihistamine medication to make a child sleepy.

What is diphenhydramine and pseudoephedrine?

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

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

Diphenhydramine and pseudoephedrine is a combination medicine used to treat sneezing, cough, runny or stuffy nose, itchy or watery eyes, hives, skin rash, itching, and other symptoms of allergies and the common cold.

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

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

Do not use diphenhydramine and pseudoephedrine if you have taken an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, phenelzine, rasagiline, selegiline, and tranylcypromine.

Ask a doctor or pharmacist if it is safe for you to take diphenhydramine and pseudoephedrine if you have:

  • kidney disease;
  • diabetes;
  • glaucoma;
  • heart disease or high blood pressure;
  • a thyroid disorder;
  • an enlarged prostate; or
  • problems with urination.

It is not known whether diphenhydramine and pseudoephedrine will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

This medication 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 your doctor's advice if you are breast-feeding a baby.

Artificially sweetened liquid cough or 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 pseudoephedrine?

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.

You should not use antihistamine medication to make a child sleepy.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. 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.

This medication can cause unusual results with allergy skin tests. Tell any doctor who treats you that you are taking an antihistamine.

Store the medication at room temperature away from moisture and heat.

What happens if I miss a dose?

Since cold or allergy medicine 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.

What should I avoid while taking diphenhydramine and pseudoephedrine?

This medication 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 with this medicine can cause side effects.

Ask a doctor or pharmacist before using any other cold, allergy, or sleep medicine. Many combination medicines contain diphenhydramine or pseudoephedrine. Taking certain products together can cause you to get too much of this medicine. Check the label to see if a medicine contains an antihistamine or decongestant.

What are the possible side effects of diphenhydramine and pseudoephedrine?

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

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

  • pounding heartbeats or fluttering in your chest;
  • confusion, hallucinations, unusual thoughts or behavior;
  • severe dizziness, anxiety, or nervousness;
  • little or no urination: or
  • high blood pressure (severe headache, blurred vision, pounding in your neck or ears).

Common side effects may include:

  • dizziness, drowsiness;
  • blurred vision;
  • dry mouth;
  • nausea, constipation;
  • loss of appetite; or
  • feeling restless or excited (especially in children).

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 pseudoephedrine?

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 pseudoephedrine 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 pseudoephedrine.


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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