Diphenhydramine

dye-fen-HYE-dra-meen

Indications for Use

Treats symptoms caused by hay fever, allergies, or the common cold. May be used as a nighttime sleep aid. Belongs to a class of drugs called antihistamines.

Brand Name(s)

Dytan

Benadryl

Benadryl Allergy

Children's Benadryl Allergy Fastmelt

Serabrina LA France

Quenalin

Siladryl Allergy

Allermax

The Medicine Shoppe Medi-Phedryl

Dytuss

Silphen

Benylin Decongestant Cough

Children's Pedia Care

Diphenhydramine HCl

Diphenyl Elixir

There may be other brand names for this medicine.

When You Should Not Take the Medication

You should not use this medicine if you have ever had an allergic reaction to diphenhydramine. This medicine should not be given to newborn infants or women who are breast feeding.

How to Use this Medicine

Capsule, Dissolving Tablet, Tablet, Liquid, Liquid Filled Capsule, Chewable Tablet

Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.

If you are using this medicine without a prescription, follow the instructions on the medicine label.

Measure the oral liquid medicine with a marked measuring spoon, oral syringe, or medicine cup.

Swallow the capsule, tablet, and liquid filled capsule whole. Do not crush, break, or chew it.

The chewable tablet must be chewed completely before you swallow it.

If you are using the disintegrating tablet, make sure your hands are dry before you handle the tablet. Do not open the blister pack that contains the tablet until you are ready to take it. Remove the tablet from the blister pack by peeling back the foil, then taking the tablet out. Do not push the tablet through the foil. Place the tablet in your mouth. It should melt quickly. After the tablet has melted, swallow or take a drink of water.

If a Dose is Missed

If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.

How to Store and Dispose of this Medicine

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Do not freeze the liquid.

Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.

Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

Make sure your doctor knows if you are using an MAO inhibitor (MAOI) such as Eldepryl®, Marplan®, Nardil®, or Parnate®.

Ask your doctor before you use any other products that have diphenhydramine in it. This includes medicines that you use on your skin.

Tell your doctor if you are using any medicines that make you sleepy. These include sleeping pills, cold and allergy medicine, narcotic pain relievers, and sedatives.

Do not drink alcohol while you are using this medicine.

Warnings While Using this Medicine

Make sure your doctor knows if you are pregnant or breast feeding, or if you have an enlarged prostate, or trouble urinating. Tell your doctor if you have glaucoma, or a breathing problem such as emphysema, bronchitis, or asthma. Make sure your doctor knows if you have any other allergies.

This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.

This medicine might contain phenylalanine (aspartame). This is a concern if you have a disorder called phenylketonuria (a problem with amino acids). If you have this condition, talk to your doctor before using this medicine.

Possible Side Effects While Using this Medicine

Call your doctor right away if you notice any of these side effects:

Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing.
Hallucinations (seeing things that are not really there).
Lightheadedness or fainting.
Pain when urinating, or change in how much or how often you urinate.

If you notice these less serious side effects, talk with your doctor:

Clumsiness.
Constipation, nausea, or stomach upset.
Dry nose, mouth, or throat.
Nervousness or excitability, especially in children.
Upset stomach.
Thick mucus in your nose or throat.

If you notice other side effects that you think are caused by this medicine, tell your doctor.