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 Taken

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.

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, use 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 use 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.

• Benadryl may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol or certain medicines. Use Benadryl with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
• Do not drink alcohol or use medicines that may cause drowsiness (e.g., sleep aids, muscle relaxers) while you are using Benadryl; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
• Benadryl may cause dizziness, lightheadedness, or fainting; alcohol, hot weather, exercise, or fever may increase these effects. To prevent them, sit up or stand slowly, especially in the morning. Sit or lie down at the first sign of any of these effects.
• Do not become overheated in hot weather or while you are being active; heatstroke may occur.
• Benadryl may cause you to become sunburned more easily. Avoid the sun, sunlamps, or tanning booths until you know how you react to Benadryl. Use a sunscreen or wear protective clothing if you must be outside for more than a short time.
• Benadryl has diphenhydramine in it. Before you start any new medicine, check the label to see if it has diphenhydramine in it too. If it does or if you are not sure, check with your doctor or pharmacist.
• Do not use Benadryl for a cough with a lot of mucous. Do not use it for a long-term cough (eg, caused by asthma, emphysema, smoking). However, you may use it for these conditions if your doctor tells you to.
• If your symptoms persist for more than 1 week or if you develop a fever, contact your health care provider.
• Use Benadryl with caution in the elderly; they may be more sensitive to its effects, especially dizziness, sedation, and lightheadedness upon standing.
• Different brands of Benadryl may have different dosing instructions for children. Follow the dosing instructions on the package labeling. If your doctor has given you instructions, follow those. If you are unsure of the dose to give a child, check with your doctor or pharmacist.
• Pregnancy and breast-feeding: If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Benadryl while you are pregnant. Benadryl is found in breast milk. Do not breast-feed while 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.

• 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.