Why is this medication prescribed?

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

• Allergic reactions: Diphenhydramine is often prescribed to relieve symptoms of allergic reactions, such as itching, hives, sneezing, runny nose, and itchy or watery eyes. It can be used to manage allergic reactions caused by insect stings or bites, pollen, dust, pet dander, and certain foods.
• Sleep aid: Diphenhydramine is found in many over-the-counter sleep aids, as it has a sedative effect that can help individuals with insomnia or difficulty falling asleep. It is not typically recommended for long-term use as a sleep aid due to potential side effects and reduced effectiveness over time.
• Motion sickness: Diphenhydramine can be used to prevent and alleviate motion sickness, such as nausea, vomiting, and dizziness caused by traveling in a car, plane, or boat.
• Cough and cold symptoms: Some cough and cold medications include diphenhydramine as an ingredient to relieve symptoms like a runny nose, sneezing, and coughing. It is an antihistamine that can help reduce these symptoms.
• Pruritus (itching): Diphenhydramine can be used to alleviate itching associated with various conditions, including allergic reactions, insect bites, and skin disorders like eczema.

How should this medicine be used?

How Diphenhydramine should be used:

• Follow your healthcare provider’s or the product label’s instructions carefully regarding the dosing and administration of diphenhydramine.
• Diphenhydramine is available in various forms, including tablets, capsules, liquid, and topical creams or gels. The appropriate form and dose depend on the specific condition being treated and the individual’s age and weight.
• When using diphenhydramine as a sleep aid, take it 30 minutes to an hour before bedtime, as it may cause drowsiness.
• Do not exceed the recommended dosage, as taking too much diphenhydramine can lead to side effects and potentially harmful effects on your health.
• It is essential to be aware of possible side effects, which may include drowsiness, dizziness, dry mouth, and constipation. Avoid activities that require mental alertness, such as driving, when you are under the influence of diphenhydramine.
• If you are taking other medications or have any preexisting medical conditions, consult with your healthcare provider or pharmacist before using diphenhydramine to avoid potential interactions or complications.
• Diphenhydramine is generally not recommended for use in children under the age of 2, and dosing should be carefully adjusted for pediatric patients.

Always use diphenhydramine as directed by a healthcare professional or as indicated on the product label. If you have any questions or concerns about its use, consult your healthcare provider or pharmacist for guidance.

Other uses for this medicine

Diphenhydramine has several off-label uses and special precautions that you should be aware of:

• Anxiety: In some cases, healthcare providers may prescribe diphenhydramine off-label to help manage anxiety. It has a sedative effect that can help individuals feel calmer, but it is not the first-line treatment for anxiety.
• Parkinson’s Disease: Diphenhydramine is sometimes used in Parkinson’s disease as an adjunct treatment to manage certain symptoms, such as tremors and muscle rigidity.
• Nausea and Vomiting: Diphenhydramine can be used to treat nausea and vomiting caused by various conditions, including chemotherapy-induced nausea and motion sickness.
• Pruritus (itching) associated with other medical conditions: Besides allergies and insect bites, diphenhydramine may be used to alleviate itching related to conditions like chronic urticaria, atopic dermatitis, or eczema.
• Migraines: Some individuals use diphenhydramine to relieve migraines, as it can help with the associated symptoms of nausea and insomnia. However, it is not a primary treatment for migraines, and there are more specific migraine medications available.

What special precautions should I follow?

Special Precautions:

• Allergies: Inform your healthcare provider if you are allergic to diphenhydramine or any other antihistamines. Allergic reactions to medications can be severe.
• Medical Conditions: Before taking diphenhydramine, discuss your medical history with your healthcare provider, especially if you have conditions such as asthma, chronic obstructive pulmonary disease (COPD), glaucoma, prostate problems, or urinary retention. These conditions may be exacerbated by diphenhydramine.
• Pregnancy and Breastfeeding: If you are pregnant or breastfeeding, consult with your healthcare provider before using diphenhydramine. While it is generally considered safe for short-term use during pregnancy, it is essential to discuss its potential risks and benefits.
• Drowsiness: Diphenhydramine can cause drowsiness and impair your ability to perform tasks that require alertness, such as driving. Avoid alcohol and other medications that can increase drowsiness when taking diphenhydramine.
• Interactions: Inform your healthcare provider about all the medications you are taking, including prescription, over-the-counter, and herbal supplements, as diphenhydramine may interact with certain drugs. It is particularly important to avoid taking multiple medications that contain diphenhydramine simultaneously to prevent overdosing.
• Age: Be cautious when using diphenhydramine in older adults, as they may be more sensitive to its side effects, including dizziness, drowsiness, and an increased risk of falls.
• Children: Use diphenhydramine in children only as directed by a healthcare provider, and carefully follow dosing instructions based on the child’s age and weight. Do not use it in children under 2 years old without specific medical guidance.

Always follow your healthcare provider’s advice and read the product label carefully to ensure safe and appropriate use of diphenhydramine. If you experience any adverse effects or have concerns about its use, consult with a healthcare professional.

What special dietary instructions should I follow?

There are no specific dietary instructions for diphenhydramine. However, consider the following tips:

• Food: Diphenhydramine can be taken with or without food. However, taking it with food may help reduce stomach upset.
• Grapefruit Juice: Some medications can interact with grapefruit juice, but diphenhydramine is generally not affected by it. Still, it’s a good practice to ask your healthcare provider or pharmacist if you have concerns about interactions with specific foods.

What should I do if I forget a dose?

If you forget to take a dose of diphenhydramine:

• If it’s close to your next dose: Skip the missed dose and take your next dose at the scheduled time.
• If it’s not close to your next dose: Take the missed dose as soon as you remember. However, if it’s almost time for your next dose, skip the missed dose and continue with your regular dosing schedule.
• Do not double dose: Do not take extra diphenhydramine to make up for the missed dose, as it can increase the risk of side effects.

What side effects can this medication cause?

Diphenhydramine can cause a range of side effects, and the severity and likelihood of these side effects can vary from person to person. Common side effects include:

• Drowsiness: One of the most common side effects of diphenhydramine is drowsiness. This sedative effect is often why it is used as a sleep aid. However, it can also impair your ability to concentrate and perform tasks that require alertness, such as driving or operating heavy machinery.
• Dry Mouth: Diphenhydramine can cause a dry or parched feeling in the mouth. This is because it has anticholinergic properties, which can reduce saliva production.
• Dizziness: Some people may experience dizziness or lightheadedness while taking diphenhydramine, especially when getting up from a sitting or lying position.
• Blurred Vision: Diphenhydramine can cause temporary blurred vision or difficulty focusing, which can affect your ability to see clearly.
• Constipation: It can lead to constipation in some individuals, as it reduces bowel movements by slowing down gut motility.
• Urinary Retention: Diphenhydramine may cause difficulty in passing urine, especially in men with an enlarged prostate gland. This can lead to urinary retention.
• Increased Heart Rate: Some people may experience an increased heart rate (tachycardia) or palpitations while taking diphenhydramine.
• Upset Stomach: Nausea and stomach discomfort can occur as a side effect in some individuals.
• Nervousness or Excitability: In some cases, diphenhydramine can have paradoxical effects, causing nervousness, restlessness, or excitability.
• Skin Reactions: Although rare, some individuals may experience skin reactions, such as rash or itching, as a side effect.
• Allergic Reactions: In rare instances, diphenhydramine can trigger allergic reactions in some people, including hives, itching, swelling of the face, lips, tongue, or throat, and difficulty breathing. Seek immediate medical attention if you experience any signs of an allergic reaction.
• Hallucinations or Confusion: In older adults, especially with high doses or prolonged use, diphenhydramine can lead to confusion, memory problems, and hallucinations.

It’s important to use diphenhydramine as directed by a healthcare provider or according to the product label instructions. If you experience severe or bothersome side effects, consult your healthcare professional. Additionally, be cautious when using diphenhydramine in combination with other medications, as drug interactions can increase the risk of side effects. If you have concerns about potential interactions, consult with a healthcare provider or pharmacist.

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

Storage and disposal of diphenhydramine:

Storage:

• Keep out of Reach of Children: Store diphenhydramine and all medications out of the reach of children and pets to prevent accidental ingestion.
• Storage Conditions: Store diphenhydramine at room temperature, away from excessive heat, moisture, and light. Follow the specific storage instructions provided on the product label.
• Original Container: Keep diphenhydramine in its original container to ensure that it’s properly labeled and identified.

Disposal:

• Safe Disposal: Do not dispose of diphenhydramine or any medications by flushing them down the toilet or pouring them down the drain unless instructed to do so by specific disposal instructions or a healthcare provider.
• Medication Take-Back Programs: Many communities have medication take-back programs or designated collection sites where you can safely dispose of unused or expired medications. Check with your local pharmacy, healthcare facility, or government agency for information on disposal options in your area.
• Household Trash: If a take-back program is not available, you can dispose of diphenhydramine by mixing it with an undesirable substance (like used coffee grounds or kitty litter) in a sealed plastic bag and placing it in your household trash. This helps make the medication less appealing to pets or children who might dig through the trash.

In case of emergency/overdose

• In case of overdose or accidental ingestion, call your local poison control center at 1-800-222-1222 or seek immediate medical attention. Be prepared to provide information about the person’s age, weight, the amount of diphenhydramine ingested, and the time of ingestion.
• Signs of overdose can include severe drowsiness, confusion, hallucinations, rapid heartbeat, flushing, fever, dilated pupils, seizures, and difficulty breathing.
• Do not induce vomiting unless directed to do so by medical professionals. Treatment for diphenhydramine overdose may include activated charcoal to absorb the drug, medications to control symptoms, and supportive care in a hospital setting.

What other information should I know?

• Avoid Alcohol: It is advisable to avoid alcohol while taking diphenhydramine, as it can intensify the sedative effects and increase the risk of side effects.
• Interactions: Inform your healthcare provider about all the medications and supplements you are taking, as diphenhydramine may interact with other drugs, potentially leading to adverse effects.
• Pregnancy and Breastfeeding: If you are pregnant or breastfeeding, consult with your healthcare provider before using diphenhydramine. Discuss the potential risks and benefits of its use during pregnancy or while breastfeeding.
• Allergies: If you are allergic to diphenhydramine or any other antihistamines, inform your healthcare provider before using it.
• Medical Conditions: Share your medical history, especially if you have conditions like glaucoma, asthma, or an enlarged prostate, as these conditions may be affected by diphenhydramine.

Always use diphenhydramine as directed by your healthcare provider or the product label instructions, and if you have any questions or concerns about its use, consult with a healthcare professional or pharmacist.