Diphenhydramine Hydrochloride

This article examines various clinical trials investigating the use of Diphenhydramine Hydrochloride, a common antihistamine medication. These studies explore its effectiveness in treating conditions such as allergies, sleeplessness, and its pharmacokinetic properties in different age groups. The trials also compare Diphenhydramine Hydrochloride with other medications and formulations, providing valuable insights into its efficacy and safety profile.

Table of Contents

What is Diphenhydramine Hydrochloride?

Diphenhydramine Hydrochloride is a medication that belongs to a class of drugs called antihistamines. It’s commonly known by its brand name Benadryl[1]. This medication works by blocking the effects of histamine, a substance in the body that causes allergic symptoms[2].

Medical Uses

Diphenhydramine Hydrochloride is used to treat various conditions, including:

  • Allergies: It helps relieve symptoms of hay fever and other upper respiratory allergies, such as sneezing, runny nose, and itchy eyes[1].
  • Insomnia: Due to its sedating effects, it’s also used as a sleep aid to treat occasional sleeplessness[3].
  • Motion Sickness: It can help prevent and treat nausea, vomiting, and dizziness associated with motion sickness[2].
  • Common Cold Symptoms: It may be used to relieve some symptoms of the common cold, such as runny nose and sneezing[1].

Available Formulations

Diphenhydramine Hydrochloride is available in various forms, including:

  • Tablets (e.g., ULTRATAB tablets, KAPSEALS capsules)[2]
  • Liquid formulations (e.g., Children’s Benadryl Allergy Liquid)[1]
  • Combination products (e.g., with pain relievers like ibuprofen)[5]

Dosage and Administration

The dosage of Diphenhydramine Hydrochloride varies depending on the condition being treated, the patient’s age, and the specific formulation. Here are some general guidelines:

  • For adults and children 12 years and older: Typically 25-50 mg every 4-6 hours[2]
  • For children 2 to under 12 years: Dosage is usually based on the child’s weight and age. Always follow the instructions provided by your healthcare provider or on the product label[1]
  • For sleep: Adults may take 50 mg at bedtime[3]

It’s important to note that you should not exceed the recommended dosage, and if symptoms persist, consult your healthcare provider.

How Diphenhydramine Works in Your Body

When you take Diphenhydramine Hydrochloride, it gets absorbed into your bloodstream and starts working within about 15-30 minutes. Its effects can last for several hours. The medication reaches its peak concentration in your body (Cmax) after about 2-3 hours[2].

Your body processes and eliminates Diphenhydramine Hydrochloride over time. The half-life (the time it takes for half of the drug to be eliminated from your body) is approximately 8-9 hours in adults[4].

Side Effects and Safety Considerations

Like all medications, Diphenhydramine Hydrochloride can cause side effects. Common side effects include:

  • Drowsiness
  • Dizziness
  • Dry mouth
  • Blurred vision
  • Constipation

More serious side effects are rare but can occur. If you experience any unusual symptoms, contact your healthcare provider immediately[3].

It’s important to note that Diphenhydramine can cause next-day drowsiness and may affect your ability to drive or operate machinery. In one study, it was found to impact simulated driving performance even 7.25 hours after taking the medication[4].

Ongoing Research

Researchers continue to study Diphenhydramine Hydrochloride to better understand its effects and potential uses. Some recent studies have focused on:

  • Its use in combination with other medications for treating migraines[6]
  • Comparing its effectiveness to other formulations and dosages[5]
  • Investigating its pharmacokinetics (how the body processes the drug) in different age groups[1]

These ongoing studies help healthcare providers better understand how to use Diphenhydramine Hydrochloride safely and effectively for various conditions.

Aspect Details
Conditions Studied Allergic rhinitis, occasional sleeplessness, nasal congestion
Age Groups Children (2-12 years), adolescents (12-18 years), adults
Formulations Liquid, tablets, capsules
Comparisons Placebo, cetirizine hydrochloride, different Diphenhydramine HCl formulations
Main Outcomes Pharmacokinetics, efficacy in symptom reduction, safety, bioequivalence
Key Measurements Drug concentration, sleep onset time, allergy symptom scores, adverse events

Ongoing Clinical Trials on Diphenhydramine Hydrochloride

  • A Study of Linvoseltamab in Adult Patients with High-Risk Monoclonal Gammopathy of Undetermined Significance or Non-High-Risk Smoldering Multiple Myeloma

    Recruiting

    1 1 1
    Belgium France Ireland Italy Poland Spain
  • Study on Esketamine and Diphenhydramine for Treating Depression and Negative Symptoms in Schizophrenia Patients

    Recruiting

    1 1 1 1
    Austria
  • Study of Linvoseltamab in Adults with Relapsed or Refractory Multiple Myeloma

    Recruiting

    1 1
    Belgium Spain
  • Study on the Safety and Effectiveness of Linvoseltamab, Sarilumab, and Dexamethasone in Adults with Relapsed or Refractory AL Amyloidosis

    Recruiting

    1 1 1
    Greece Spain
  • Study on Long-Term Safety of mRNA-3705 for Patients with Methylmalonic Acidemia (MMA)

    Recruiting

    1 1 1
    France The Netherlands Spain
  • Study on the Effectiveness and Safety of Dapirolizumab Pegol for Patients with Moderate to Severe Systemic Lupus Erythematosus

    Recruiting

    1 1 1
    Belgium Denmark France Germany Greece Italy +3
  • Study on the Long-Term Safety of Dapirolizumab Pegol for Patients with Systemic Lupus Erythematosus

    Recruiting

    1 1 1 1
    Belgium Bulgaria Czechia Denmark France Germany +7
  • Study on Gene Therapy with AAV9.LAMP2B for Male Patients with Danon Disease

    Recruiting

    1 1 1
    Germany Italy
  • Zanidatamab, tucatinib, capecitabine or eribulin mesylate in HER2-positive advanced breast cancer in adults

    Not yet recruiting

    1 1 1
    Spain
  • A Study of Linvoseltamab Alone and Linvoseltamab with Carfilzomib Compared to Standard Treatment in Adults with Relapsed or Refractory Multiple Myeloma

    Not yet recruiting

    1 1 1 1
    Austria Belgium Czechia France Germany Greece +4

Glossary

  • Pharmacokinetics: The study of how a drug moves through the body, including its absorption, distribution, metabolism, and excretion. This helps understand how the body processes the medication.
  • Bioequivalence: A comparison of the biological equivalence of two preparations of a drug. It's used to show that two formulations of the same drug have the same effect in the body.
  • Allergic Rhinitis: An allergic reaction that causes inflammation in the nose, often referred to as hay fever. Symptoms include sneezing, runny nose, and itchy eyes.
  • Occasional Sleeplessness: Difficulty falling asleep or staying asleep that occurs from time to time, not on a regular basis.
  • Placebo: A substance with no active therapeutic effect, used as a control in testing new drugs. It helps determine the effectiveness of the actual medication being studied.
  • Adverse Events: Any unfavorable and unintended sign, symptom, or disease that occurs during the use of a medical treatment, whether or not it is caused by the treatment.
  • Cmax: The maximum concentration of a drug in the blood, plasma, or serum after administration. It's an important measure in pharmacokinetic studies.
  • AUC (Area Under the Curve): A measure of the total exposure to a drug over time. It represents the total amount of drug in the bloodstream after a dose is administered.

References

  1. https://clinicaltrials.gov/study/NCT00762749
  2. https://clinicaltrials.gov/study/NCT00662337
  3. https://clinicaltrials.gov/study/NCT02578186
  4. https://clinicaltrials.gov/study/NCT01888497
  5. https://clinicaltrials.gov/study/NCT05729555
  6. https://clinicaltrials.gov/study/NCT03877718