Why is this medication prescribed?

Diphenhydramine is prescribed for several reasons, primarily due to its antihistamine properties. It is commonly used for the following purposes:

• Allergies and Hay Fever: Diphenhydramine is used to relieve symptoms such as sneezing, itching, watery eyes, and runny nose caused by allergies or hay fever.
• Common Cold: It may be used to alleviate symptoms associated with the common cold, such as a runny nose and sneezing.
• Itching and Skin Conditions: Diphenhydramine can be prescribed or recommended for the relief of itching and discomfort associated with skin conditions like hives, eczema, and insect bites.
• Motion Sickness: It is sometimes used to prevent and treat symptoms of motion sickness, including nausea and vomiting.
• Insomnia (Off-Label): While not a primary indication, diphenhydramine’s sedative effects can be used to aid sleep. It is found in many over-the-counter sleep aids.

It’s important to note that diphenhydramine is available over-the-counter in various forms, including oral tablets, capsules, and liquid formulations. It’s essential to use the medication according to the recommended dosage and guidelines provided on the product packaging or as directed by a healthcare professional.

How should this medicine be used?

Diphenhydramine is typically taken orally, and the dosage may vary depending on the specific condition being treated, the formulation of the medication, and the individual’s age. It’s important to follow the dosing instructions provided on the product packaging or as directed by a healthcare professional. Here are some general guidelines:

• Allergies, Hay Fever, Itching, Rash, and Hives:
  • Adults and children over 12 years old: The usual dose is 25 to 50 mg every 4 to 6 hours.
  • Children 6 to 12 years old: The usual dose is 12.5 to 25 mg every 4 to 6 hours.
• Insomnia (as a sleep aid):
  • Adults: The usual dose is 50 mg taken 30 minutes before bedtime.
  • It’s important to note that diphenhydramine should not be used for more than a few days in a row for insomnia, as its effectiveness may diminish with prolonged use.
• Motion Sickness:
  • The recommended dose varies based on age, and it is typically taken 30 minutes before travel.

Always use the lowest effective dose to manage symptoms and avoid exceeding the recommended dosage. If you have any questions or concerns about how to use diphenhydramine, consult with a healthcare professional.

Other uses for this medicine

Apart from the primary uses mentioned above, diphenhydramine may be used off-label for:

• Insomnia: Due to its sedative effects, it’s included in some over-the-counter sleep aids.
• Anaphylaxis: In emergency situations, diphenhydramine may be part of the treatment for severe allergic reactions.

What special precautions should I follow?

Special precautions to consider when using diphenhydramine include:

• Sedation: Diphenhydramine can cause drowsiness and impair alertness. Individuals taking this medication should be cautious when engaging in activities that require mental alertness, such as driving or operating heavy machinery.
• Avoid Alcohol: Consuming alcohol while taking diphenhydramine can enhance the sedative effects and increase the risk of drowsiness. It’s generally recommended to avoid alcohol during treatment.
• Medical Conditions: Individuals with certain medical conditions, such as glaucoma, asthma, enlarged prostate, urinary retention, high blood pressure, or cardiovascular disease, should use diphenhydramine with caution and under the guidance of a healthcare professional.
• Pregnancy and Breastfeeding: Pregnant or breastfeeding individuals should consult their healthcare provider before using diphenhydramine to weigh the potential risks and benefits.
• Interactions with Other Medications: Diphenhydramine can interact with other medications, including sedatives, tranquilizers, and monoamine oxidase inhibitors (MAOIs). Inform your healthcare provider about all the medications you are taking.

Always follow the specific instructions provided by your healthcare provider or on the product packaging. If you have any concerns or experience adverse effects, seek medical advice promptly.

What special dietary instructions should I follow?

There are generally no specific dietary restrictions associated with diphenhydramine. However, taking it with food or a glass of milk can help minimize stomach upset.

What should I do if I forget a dose?

If you miss a dose of diphenhydramine, take it as soon as you remember. However, if it’s almost time for your next scheduled dose, skip the missed dose and continue with your regular dosing schedule. Do not double up on doses to make up for a missed one.

What side effects can this medication cause?

Diphenhydramine can cause various side effects, and individuals may react differently to the medication. It’s essential to be aware of potential side effects and to seek medical attention if you experience any concerning symptoms. Here are some common side effects associated with diphenhydramine:

Common Side Effects:

• Drowsiness
• Dry mouth
• Blurred vision
• Constipation
• Urinary retention (difficulty urinating)
• Confusion, especially in older adults
• Dizziness

Less Common Side Effects:

• Nausea and vomiting
• Headache
• Upset stomach
• Changes in appetite
• Excitability, especially in children

Serious Side Effects (Rare, but may occur):

• Allergic reactions (rash, itching, swelling, severe dizziness, difficulty breathing)
• Severe drowsiness or difficulty waking up
• Rapid or irregular heartbeat
• Tremors or seizures
• Problems with coordination
• Hallucinations
• Trouble urinating

If you experience any severe or persistent side effects, seek medical attention immediately. In the case of an allergic reaction, such as difficulty breathing or swelling of the face, lips, or tongue, seek emergency medical help.

It’s important to note that diphenhydramine can interact with other medications, and certain medical conditions may increase the risk of side effects. Inform your healthcare provider about all medications you are taking and any existing health conditions before using diphenhydramine.

Additionally, long-term or frequent use of diphenhydramine for sleep aid purposes is not recommended, as it may lead to tolerance and reduced effectiveness. If you have concerns about side effects or the use of diphenhydramine, consult with your healthcare professional.

What should I know about storage and disposal of this medication?

Storage:

• Store diphenhydramine at room temperature, away from light and moisture.
• Keep it out of reach of children and pets.
• Follow any specific storage instructions provided on the product packaging.

Disposal:

• Dispose of expired or unused diphenhydramine properly.
• Follow local regulations for medication disposal. Do not flush medications down the toilet unless instructed to do so.

In case of emergency/overdose

• In case of an overdose or emergency, call your local emergency services (such as 911 in the United States) immediately.
• Symptoms of overdose may include extreme drowsiness, seizures, confusion, hallucinations, and a rapid or irregular heartbeat.
• If possible, provide information about the amount of diphenhydramine taken.

What other information should I know?

• Inform your healthcare provider about all medications you are taking, including over-the-counter drugs and herbal supplements.
• Avoid alcohol while taking diphenhydramine, as it can enhance the sedative effects.
• Inform your healthcare provider about any existing medical conditions, including asthma, glaucoma, high blood pressure, and urinary problems.
• Be cautious when engaging in activities that require mental alertness, as diphenhydramine can cause drowsiness.
• If you are pregnant, breastfeeding, or planning to become pregnant, consult with your healthcare provider before using diphenhydramine.

Always follow the specific instructions provided by your healthcare provider or on the product packaging. If you have any concerns, experience adverse effects, or have questions about the medication, consult with your healthcare professional. In case of an emergency or overdose, seek medical attention promptly.