Generic Name: Diphenhydramine Brand Name(s): Generics only. No brands available.

Uses

What is diphenhydramine used for?

Diphenhydramine is commonly used for symptomatic relief of cough, alleviation of nasal and bronchial congestion.

Diphenhydramine may also be used for other purposes, ask your doctor for more information.

How should I take diphenhydramine?

For orally taken form, you should:

  • Take diphenhydramine by mouth as directed by your doctor concerning: dose, schedule.
  • Read the label carefully before using diphenhydramine.
  • Consult your doctor for any information on the label that you do not clearly understand.

How do I store diphenhydramine?

Diphenhydramine is best stored at room temperature away from direct light and moisture. To prevent drug damage, you should not store diphenhydramine in the bathroom or the freezer. There may be different brands of diphenhydramine that may have different storage needs. It is important to always check the product package for instructions on storage, or ask your pharmacist. For safety, you should keep all medicines away from children and pets.

You should not flush diphenhydramine down the toilet or pour them into a drain unless instructed to do so. It is important to properly discard this product when it is expired or no longer needed. Consult your pharmacist for more details about how to safely discard your product.

Precautions & warnings

What should I know before using diphenhydramine?

Before using diphenhydramine, tell your doctor if you have:

  • Allergic reaction to excipients using for dosage form containing diphenhydramine.
  • Allergic reaction to any other medicines, foods, dyes, preservatives, or animals.
  • Used any other health conditions, drugs that have a risk of interaction with diphenhydramine as listed below: narrow-angle glaucoma, bronchial asthma, hyperthyroidism, CV disease, prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, bladder neck obstruction, glucose-6-phosphate deficiency.

Is it safe during pregnancy or breastfeeding?

There isn’t enough information about the safety of using diphenhydramine during pregnancy and breastfeeding. Please always consult with your doctor to weigh the potential benefits and risks before taking diphenhydramine.

Side effects

What side effects can occur from diphenhydramine?

As taking others medicines, taking diphenhydramine can cause some side effects. Most of them are rarely occurring and do not need any supplementary treatment. However, it is always important for you to consult your doctor if you have any problem after taking this medicine.

Some of side effects are listed below:

  • Sedation
  • Dizziness
  • Hypotension
  • Muscular weakness
  • Incoordination
  • GI disturbance
  • Headache
  • Blurred vision
  • Tinnitus
  • Elation or depression
  • Irritability
  • Nightmares
  • Anorexia
  • Difficulty in micturition
  • Dry mouth
  • Tightness of chest
  • Tingling
  • Heaviness and weakness of hands

Not everyone experiences these side effects. There may be some side effects not listed above. If you have any concerns about a side-effect, please consult your doctor or pharmacist.

Interactions

What drugs may interact with diphenhydramine?

Diphenhydramine may interact with other drugs that you are currently taking, which can change how your drug works or increase your risk for serious side effects. To avoid any potential drug interactions, you should keep a list of all the drugs you are using (including prescription drugs, nonprescription drugs, and herbal products) and share it with your doctor and pharmacist. For your safety, do not start, stop, or change the dosage of any drugs without your doctor’s approval.

Products may interact with this drug, such as:

  • Hypnotics
  • Sedatives
  • Tranquilizers
  • MAOIs
  • Aminoglycosides
  • Antimuscarinics

Does food or alcohol interact with diphenhydramine?

Diphenhydramine may interact with food or alcohol by altering the way the drug works or increase the risk for serious side effects. Please discuss with your doctor or pharmacist any potential food or alcohol interactions before using this drug.

What health conditions may interact with diphenhydramine?

Diphenhydramine may interact with your health condition. This interaction may worsen your health condition or alter the way the drug works. It is important to always let your doctor and pharmacist know all the health conditions you currently have.

These health conditions are:

  • Narrow-angle glaucoma
  • Bronchial asthma
  • Hyperthyroidism
  • CV disease
  • Prostatic hypertrophy
  • Stenosing peptic ulcer
  • Pyloroduodenal obstruction
  • Bladder neck obstruction
  • Glucose-6-phosphate deficiency

Dosage

The information provided is not a substitute for any medical advice. You should ALWAYS consult with your doctor or pharmacist before using diphenhydramine.

What is the dose of diphenhydramine for an adult?

Consult your doctor for information about the dose of diphenhydramine.

Recommended doses in some cases are listed below:

  • Allergic reaction: 25-50 mg PO q6-8hr; not to exceed 300 mg/day.
  • Insomnia: 50 mg PO 30 minutes before bedtime.
  • Cough: 25-50 mg PO q4hr PRN (syrup preferred); not to exceed 150 mg/d.
  • Motion sickness: treatment or prophylaxis: 25-50 mg PO q6-8 hr. Alternatively, 10-50 mg/dose for treatment; may use up to 100 mg if needed; not to exceed 400 mg.
  • Parkinsonism: 25 mg PO q8hr initially, then 50 mg PO q6hr; not to exceed 300 mg/day.

What is the dose of diphenhydramine for a child?

Consult your doctor for information about the dose of diphenhydramine.

Recommended doses in some cases are listed below:

Allergic reaction

  • 2-6 years: 6.25 mg q4-6hr; not to exceed 37.5 mg/day.
  • 6-12 years: 12.5-25 mg PO q4-6hr; not to exceed 150 mg/day.
  • >12 years: 25-50 mg PO q4-6hr; not to exceed 300 mg/day.

Occasional insomnia

  • < 12 years (off-label): 1 mg/kg; not to exceed 50 mg; 30 min before bedtime.
  • >12 years: 50 mg PO 30 minutes before bedtime.

Cough

  • <12 years: Safety and efficacy not established.
  • >12 years: 25-50 mg PO q4-6hr; not to exceed 300 mg/day.

Motion sickness

  • Administer 30 min before motion.
  • 5-25 mg PO q6-8hr or 150 mg/m²; not to exceed 300 mg/day.

The dosage has not been established in pediatric patients. It may be unsafe for your child. It is always important to fully understand the safety of the drug before using. Please consult with your doctor or pharmacist for more information.

How is diphenhydramine available?

Diphenhydramine is available in the following dosage forms and strengths:

  • Caplet 25 mg

What should I do in case of an emergency or overdose?

In case of an emergency or an overdose, call your local emergency services or go to your nearest emergency room.

What should I do if I miss a dose?

If you miss a dose of diphenhydramine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and take your regular dose as scheduled. Do not take a double dose.

Hello Health Group does not provide medical advice, diagnosis or treatment.

 

Sources

Review Date: January 7, 2017 | Last Modified: January 7, 2017