Benadryl Anthistamine

Antihistamines are a class of drugs primarily used to treat symptoms associated with allergies and other conditions related to the release of histamine in the body. Histamine is a naturally occurring compound produced by certain cells in response to an allergen. It's part of the body's defense mechanism, helping to remove allergens by increasing blood flow and attracting other immune system cells to the affected area. While this reaction is beneficial in protecting the body, it can also cause symptoms that many people recognize as allergic reactions, such as itching, swelling, runny nose, and watery eyes. These medications work by blocking the action of histamine, thus alleviating or preventing the symptoms associated with its release. They bind to the receptors in the body that histamine would typically attach to, preventing it from exerting its effects.

The top 5 Antihistamines

Product name Image Rating Pros Cons Best Price More information

Benadryl (Diphenhydramine)

Benadryl Anthistamine 5 star review
  • Quick relief from allergy symptoms
  • Can also be used as a sleep aid due to its sedative properties
  • Over-the-counter availability
  • Can cause drowsiness
  • Not suitable for prolonged use
  • Might cause dry mouth or other anticholinergic side effects
Coming Soon!

Claritin (Loratadine)

Claritin Antihistamine
  • Non-drowsy formula
  • Once-a-day dosing
  • Long-lasting relief from allergy symptoms
  • Not as potent as some other antihistamines
  • Can still cause drowsiness in a minority of users
  • Occasionally, users might experience headaches
Coming Soon!

Zyrtec (Cetirizine)

Zyrtec (Cetirizine)
  • Rapid onset of action
  • Effective for treating various allergy symptoms
  • Once-a-day dosing
  • Some users might experience drowsiness
  • Not recommended for those with severe kidney problems
  • Might cause dry mouth or stomach pain in some users
Coming Soon!

HealthCareAisle Allergy Relief (Fexofenadine)

HealthCareAisle Allergy Relief
  • Non-drowsy formula
  • Effective for treating a wide range of allergy symptoms
  • Super affordable
  • Should be taken on an empty stomach for best absorption.
  • Rarely, can cause headaches or stomach upset
Coming Soon!

Pepcid (Famotidine)

Pepcid (Famotidine) 5 star review
  • While primarily an acid reducer, it has antihistamine properties beneficial for certain allergic reactions
  • Can be used in combination with other antihistamines for comprehensive allergy relief
  • Over-the-counter availability
  • Not primarily designed for general allergy symptoms
  • Might interact with certain other medications
  • Some users might experience gastrointestinal side effects
Coming Soon!

Additional Reading

There are various types of antihistamines, and they're used to treat a range of conditions beyond just allergic reactions. The most common uses include:
  • Allergic Rhinitis This is a reaction to allergens in the air, commonly known as hay fever. Symptoms include sneezing, runny or stuffy nose, itchy or watery eyes, and an itchy throat or mouth.
  • Allergic Conjunctivitis An allergic reaction affecting the eyes, causing red, itchy, and watery eyes.
  • Chronic Urticaria A condition where red, itchy hives or welts appear on the skin without a clear cause.
  • Allergic Dermatitis A skin reaction following contact with an allergen, leading to itchy, inflamed skin.
  • Insect Bites and Stings Antihistamines can help alleviate itching and swelling caused by insect bites and stings.
  • Food Allergies While they can't treat the allergy itself, antihistamines can help alleviate some of the symptoms. However, for severe reactions, more potent treatments like epinephrine might be necessary.
  • Medication Allergies Similar to food allergies, antihistamines can help manage symptoms but aren't the primary treatment for severe reactions.
Some antihistamines can also be used for other conditions unrelated to allergies. For instance, certain antihistamines can be used to treat insomnia due to their sedative effects. Others might be used in combination with other medications to alleviate symptoms of the common cold.

The History of Antihistamines

The history of antihistamines is a fascinating journey through medical innovation. The development began in the early 20th century, driven by the discovery of histamine and its role in allergic reactions. The first antihistamine, synthesized in the 1930s, marked a breakthrough in treating allergies. Over the following decades, the focus shifted towards improving efficacy and reducing side effects. This led to the development of second-generation antihistamines in the 1980s, which offered greater effectiveness with fewer drowsiness side effects. Today, antihistamines are widely used worldwide, continually evolving to offer better relief for allergy sufferers.

Ingredients of Antihistamines

Antihistamines typically include active ingredients that fall into two categories: first-generation and second-generation. First-generation antihistamines, often known for their sedative properties, include ingredients such as diphenhydramine, chlorpheniramine, and promethazine. Second-generation antihistamines, which are usually less sedating, contain active ingredients like cetirizine, loratadine, and fexofenadine. These medications may also contain various other components like stabilizers and preservatives, which help in maintaining the effectiveness and shelf life of the product.

Who should take Antihistamines

Antihistamines are commonly used by individuals suffering from allergic reactions, such as hay fever, hives, and other allergies. They are effective in relieving symptoms like sneezing, itching, runny nose, and watery eyes. People experiencing allergic skin reactions, such as those caused by insect bites or stings, might also find relief using antihistamines. Additionally, they can be used to alleviate symptoms of motion sickness and to aid sleep, due to their sedative properties, particularly in the case of first-generation antihistamines. However, it's important for individuals to consult healthcare professionals before using antihistamines, especially if they have underlying health conditions or are taking other medications.

What Antihistamines are NOT intended for

Antihistamines may not be suitable for certain individuals. Those with pre-existing conditions like glaucoma, enlarged prostate, heart disease, high blood pressure, or kidney or liver disorders should use them cautiously. Pregnant or breastfeeding women are also advised to consult a healthcare provider before using antihistamines. Additionally, older adults may be more susceptible to side effects such as drowsiness or confusion, especially with first-generation antihistamines. It's always best to consult a healthcare professional before starting any new medication, including antihistamines.

Pros and Cons of Antihistamines


  • Relief from Allergy Symptoms: Effective in reducing symptoms like sneezing, itching, and runny nose.
  • Versatility: Useful for various allergies, including hay fever, pet allergies, and dust mites.
  • Additional Uses: Can help with motion sickness and aid in occasional sleep disturbances.
  • Rapid Action: Often works quickly to relieve symptoms, sometimes in as little as an hour.
  • Accessible: Available over-the-counter, making them easily accessible for most people.
  • Long-Acting Options: Second-generation antihistamines offer longer-lasting relief without frequent dosing.
  • Minimal Sedation in Newer Forms: Second-generation antihistamines have less sedative effect compared to older ones.
  • Skin Allergy Relief: Helpful in treating skin allergies and reactions like hives or contact dermatitis.


  • Heart Rate Changes: Some can cause palpitations or an increase in heart rate.
  • Interactions with Other Medications: Can interact with other drugs, leading to potential health risks.
  • Not Suitable for Everyone: Not recommended for people with certain medical conditions like glaucoma or prostate enlargement.
  • Adaptation: The body can become tolerant to antihistamines, reducing their effectiveness over time.
  • Dependency Issues: Potential for dependency when used as a sleep aid.
  • Restrictions During Pregnancy and Breastfeeding: May not be safe for use during pregnancy or breastfeeding without medical advice.
  • Age Restrictions: Not always suitable for very young children or the elderly without medical consultation.

Studies regarding the benefits of Antihistamines

Title - The therapeutic versatility of antihistamines: A comprehensive review This study provides an extensive review of the various therapeutic applications of antihistamines.

Title - Antihistamines: ABC for the pediatricians Focuses on the use of antihistamines in pediatric care, discussing their safety and efficacy for children.

Title- Antihistamines for treating rhinosinusitis: systematic review and meta-analysis of randomized controlled studies A detailed analysis of the effectiveness of antihistamines in treating rhinosinusitis.

Title - An evidence-based review of the efficacy of topical antihistamines in the relief of pruritus This review assesses the effectiveness of topical antihistamines in alleviating itching.

Title - Analysis of the Cochrane Review: Antihistamines for the Common Cold A critical examination of a Cochrane Review, focusing on the role of antihistamines in treating the common cold.

Title - The effectiveness of modern antihistamines for treatment of allergic rhinitis - an IPD meta-analysis of 140,853 patients A comprehensive meta-analysis on the effectiveness of modern antihistamines in treating allergic rhinitis.

Title - Antihistamines may improve immunotherapy responses, study finds A study exploring how antihistamines might influence the response to immunotherapy treatments.

Frequently Asked Questions about Antihistamines

What are antihistamines and how do they work?

Antihistamines are medications used to relieve symptoms of allergies, such as hay fever, hives, and other types of allergic reactions. They work by blocking the action of histamine, a substance in the body that causes allergic symptoms. Histamine binds to H1 receptors on cells in the body, leading to symptoms like itching, swelling, and vasodilation. Antihistamines prevent histamine from binding to these receptors, thereby reducing or eliminating these symptoms.

What are the different types of antihistamines?

There are two main types of antihistamines:

  • First-Generation Antihistamines: These are older antihistamines that can cross the blood-brain barrier, often causing drowsiness. Examples include diphenhydramine (Benadryl) and chlorpheniramine.
  • Second-Generation Antihistamines: These are newer antihistamines that do not easily cross the blood-brain barrier, causing less drowsiness. Examples include loratadine (Claritin), cetirizine (Zyrtec), and fexofenadine (Allegra).

What are the common uses of antihistamines?

Antihistamines are commonly used to treat:

  • Allergic Rhinitis: Symptoms include sneezing, runny nose, and itchy eyes.
  • Urticaria (Hives): Red, itchy welts on the skin.
  • Allergic Conjunctivitis: Itchy, red, and watery eyes.
  • Common Cold Symptoms: Though not always recommended, they can help relieve symptoms like a runny nose and sneezing.
  • Motion Sickness and Nausea: Some first-generation antihistamines are used for these purposes.

What are the potential side effects of antihistamines?

Side effects vary depending on the type of antihistamine:

  • First-Generation Antihistamines: Drowsiness, dry mouth, dizziness, urinary retention, and blurred vision.
  • Second-Generation Antihistamines: Generally fewer side effects, but may include headache, dry mouth, and mild drowsiness in some individuals.

It’s important to read the label and consult with a healthcare provider if you have concerns about side effects.

Can I take antihistamines with other medications?

Antihistamines can interact with other medications, so it’s important to consult with a healthcare provider before combining them. Potential interactions include:

  • Sedatives or Alcohol: Can increase drowsiness and impair coordination.
  • Antidepressants: Certain types can increase side effects.
  • Other Antihistamines: Taking multiple antihistamines can increase the risk of side effects.

Are antihistamines safe for children?

Some antihistamines are safe for children, but it’s important to use them as directed by a healthcare provider. Dosage will vary based on the child’s age and weight. Second-generation antihistamines are generally preferred for children due to their lower risk of sedation and fewer side effects.

Can antihistamines be used long-term?

Antihistamines can be used long-term under the guidance of a healthcare provider, especially for chronic conditions like allergic rhinitis. However, it’s important to:

  • Monitor for Side Effects: Long-term use can sometimes lead to side effects like dry mouth or tolerance.
  • Follow Dosage Instructions: Stick to recommended dosages to avoid potential risks.

Regular check-ins with a healthcare provider can help manage long-term use effectively.

Are there any natural alternatives to antihistamines?

Some natural remedies may help alleviate allergy symptoms, including:

  • Quercetin: A flavonoid found in fruits and vegetables that may have antihistamine effects.
  • Butterbur: An herb that has been shown to reduce allergy symptoms.
  • Stinging Nettle: Another herb that may help reduce histamine levels.
  • Vitamin C: Acts as a natural antihistamine and supports the immune system.

It’s important to consult with a healthcare provider before using natural alternatives, especially if you are taking other medications.

How quickly do antihistamines work?

The onset of action varies by type:

  • First-Generation Antihistamines: Typically begin to work within 15-30 minutes.
  • Second-Generation Antihistamines: Generally take 1-2 hours to start working.

Full effects can be seen within a few hours, and they usually last for 4-6 hours (first-generation) or up to 24 hours (second-generation).

Can I use antihistamines if I am pregnant or breastfeeding?

Some antihistamines are considered safe during pregnancy and breastfeeding, but it’s crucial to consult with a healthcare provider before using them. Generally:

  • Loratadine (Claritin) and Cetirizine (Zyrtec): Often considered safe during pregnancy.
  • Diphenhydramine (Benadryl): Sometimes used, but should be discussed with a healthcare provider.