Diphenhydramine (By mouth)
Treats hay fever, allergy, and cold symptoms. Also treats insomnia.
Aller-G-Time, Allergy Relief, Allermax, Anti-Hist, Banophen, Benadryl Allergy, Children's Allergy, Children's Benadryl Allergy, Children's Wal-Dryl Allergy, Complete Allergy, Complete Allergy Medicine, Diphen, Diphenhist, Dormin Sleep Aid, Equate Allergy Relief
When This Medicine Should Not Be Used
How to Use This Medicine
Capsule, Thin Sheet, Dissolving Tablet, Tablet, Liquid, Liquid Filled Capsule, Chewable Tablet
- Your doctor will tell you how much medicine to use. Do not use more than directed.
- Follow the instructions on the medicine label if you are using this medicine without a prescription.
- 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.
- Make sure your hands are dry before you handle the disintegrating tablet. Peel back the foil from the blister pack, then remove the tablet. Do not push the tablet through the foil. Place the tablet in your mouth. After it has melted, swallow or take a drink of water.
If a dose is missed:
- Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take 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- Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.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 out of the reach of children. 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 use anything else that makes you sleepy. Some examples are allergy medicine, narcotic pain medicine, and alcohol.
- 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 breastfeeding, 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:
- 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
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
- Last reviewed on 12/12/2016
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