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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

FAQ

  • What conditions are being studied in these clinical trials using Diphenhydramine Hydrochloride? The clinical trials are studying various conditions, including allergic rhinitis (hay fever), occasional sleeplessness, and nasal congestion. Some trials also focus on the drug's pharmacokinetics in different age groups.
  • How is Diphenhydramine Hydrochloride administered in these trials? Diphenhydramine Hydrochloride is administered in various forms across the trials, including liquid formulations, tablets, and capsules. The dosage and timing vary depending on the specific study and condition being treated.
  • What age groups are included in these clinical trials? The trials include a wide range of age groups, from children as young as 2 years old to adults. One study specifically focuses on children aged 2 to 12 years and adolescents aged 12 to 18 years.
  • Are there any comparisons made between Diphenhydramine Hydrochloride and other medications? Yes, some trials compare Diphenhydramine Hydrochloride to other medications or placebos. For example, one study compares it to cetirizine hydrochloride in treating acute urticaria, while another compares different formulations of Diphenhydramine Hydrochloride itself.
  • What are the main outcomes being measured in these clinical trials? The main outcomes being measured include pharmacokinetic parameters (such as drug concentration in the blood over time), efficacy in reducing allergy symptoms or improving sleep, and safety assessments including adverse events. Some trials also measure bioequivalence between different formulations.

Ongoing Clinical Trials on Diphenhydramine Hydrochloride

  • Study on the Safety and Efficacy of PF-06835375 and Diphenhydramine Hydrochloride for Adults with Moderate to Severe Primary Immune Thrombocytopenia

    Not recruiting

    1 1 1
    Investigated drugs:
    Czechia Hungary Poland

  • Study Comparing Idecabtagene Vicleucel and Lenalidomide Maintenance Therapy for Adults with Newly Diagnosed Multiple Myeloma After Stem Cell Transplant

    Not recruiting

    1 1 1 1
    Investigated drugs:
    Austria Belgium Czechia Denmark France Germany +6

  • Study on BI-1910 and Pembrolizumab for Patients with Advanced Solid Tumors

    Not recruiting

    1 1 1
    Investigated drugs:
    Denmark Germany Poland Spain Sweden

  • Study of Mosunetuzumab and Polatuzumab Vedotin Combination Treatment in Patients with B-Cell Non-Hodgkin Lymphoma

    Not recruiting

    1 1 1
    Investigated drugs:
    Belgium Spain

  • Study on the Safety and Effects of Ocrelizumab for Children and Adolescents with Relapsing-Remitting Multiple Sclerosis

    Not recruiting

    1 1 1
    Investigated diseases:
    Investigated drugs:
    Italy Poland

  • Study on the Effectiveness and Safety of Ocrelizumab, Methylprednisolone, and Diphenhydramine Hydrochloride in Patients with Multiple Sclerosis

    Not recruiting

    1 1 1 1
    Investigated diseases:
    Investigated drugs:
    Belgium Bulgaria Croatia Denmark France Hungary +8

  • Study of Brexucabtagene Autoleucel in Patients with Relapsed or Refractory Mantle Cell Lymphoma

    Not recruiting

    1 1 1
    Investigated diseases:
    Investigated drugs:
    France Germany The Netherlands Spain

  • Study on the Effectiveness of Imetelstat for Patients with High-Risk Myelodysplastic Syndromes or Acute Myeloid Leukemia After HMA Treatment Failure

    Not recruiting

    1 1 1
    Investigated diseases:
    Investigated drugs:
    France Germany

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