Drug Name
Benadryl (Diphenhydramine)

Drug Uses
Benadryl is used for preventing or treating symptoms of hay fever and other upper respiratory allergies or the common cold, such as runny nose, sneezing, itching of the nose and throat, and itchy, watery eyes, and relieving cough.

It may also relieve itching of the skin and allergic skin reactions. It is also used to treat and prevent motion sickness. It may also be used for other conditions as determined by your doctor.

How to use
Use Benadryl as directed by your doctor.

• Take Benadryl by mouth with or without food.
• Use Benadryl exactly as directed on the package, unless instructed differently by your doctor. If you are taking Benadryl without a prescription, follow any warnings and precautions on the label.
• For prevention of motion sickness: Take at least 30 minutes before activity or travel.

Ask your health care provider any questions you may have about how to use Benadryl.

Drug Class and Mechanism
Benadryl is an antihistamine and anticholinergic. It works by blocking the action of histamine, reducing the symptoms of an allergic reaction. It also works in the brain to cause sedation.

Missed Dose
If you miss a dose of Benadryl and you are taking it regularly, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Storage
Store Benadryl at room temperature between 68 and 77 degrees F (20 and 25 degrees C) in a tightly closed container. Brief periods at temperatures of 59 to 86 degrees F (15 to 30 degrees C) are permitted. Store away from heat, moisture, and light. Do not store in the bathroom. Keep Benadryl out of the reach of children and away from pets.

Warnings/Precautions
Do NOT use Benadryl if:

• you are allergic to any ingredient in this medicine or other similar medicines
• you are taking sodium oxybate (GHB)
• you are currently taking or have taken a monoamine oxidase (MAO) inhibitor (eg, phenelzine) in the past 14 days
• you are breast-feeding
  
  Contact your doctor or health care provider right away if any of these apply to you.
  
  Some medical conditions may interact with Benadryl. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:
  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you have asthma, chronic obstructive pulmonary disease (COPD), chronic bronchitis, emphysema, lung disease, shortness of breath, or sleep apnea
  • if you have blockage of the stomach, intestine, or urinary tract; difficulty urinating; diabetes; ulcers; enlargement of the prostate; glaucoma; heart disease; high blood pressure; porphyria; or thyroid disease
  
  
  Some MEDICINES MAY INTERACT with Benadryl. Tell your health care provider if you are taking any other medicines, especially any of the following:
  • Sodium oxybate (GHB) because an increase in sleep duration and a decrease in the ability to breathe are likely to occur
  • MAO inhibitors (eg, phenelzine) because they can cause serious, sometimes fatal, reactions. Do NOT take MAO inhibitors within 2 weeks of taking Benadryl.
  
  

Possible Side Effects
Check with your doctor if any of these most common side effects persist or become bothersome:

• dizziness; drowsiness; dry mouth, throat, and nose; excitability; thickening of mucus in nose or throat.

Seek medical attention right away if any of these severe side effects occur:

• severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); convulsions; fast heartbeat or pounding in the chest; decreased alertness; hallucinations; tremor; wheezing.

More Information
Benadryl is to be used only by the patient for whom it is prescribed. Do not share it with other people.
If your symptoms do not improve or if they become worse, check with your doctor.