Around 60% of all people with asthma have allergic asthma.
It discusses side effects, drug interactions, and other concerns.
To Treat Allergies
Antihistamines are not a first-line treatment for allergic asthma.
Illustration by Zoe Hansen for Verywell Health
That’s because histamine is not the only chemical involved in asthma symptoms.
Therefore, people use antihistamines for allergy symptoms with a limited expectation for improving allergic asthma.
But they don’t treat acute asthma symptoms and should never be taken for an asthma attack.
They’ll want to consider the specific symptoms you experience and how often they occur.
Tests
A healthcare provider may want to do ablood or skin testto confirm you have an allergy.
That way, you will know which things to avoid, if possible.
They also may want to measure your lung function withspirometry.
This test estimates your degree of airway constriction before and after using an inhaler.
Once the tests are complete, your asthma will be classified based on severity.
This classification will influence your treatment plan and the combination of medications your doctor prescribes.
Allergy Treatment
The best allergy treatment is prevention.
You may prevent symptoms by steering clear of the allergen involved, but this can be challenging.
Talk to your healthcare provider about all medications, supplements, and vitamins you currently take.
Some drugs may pose minor to severe interaction risks.
Inhalers
Aninhaleris a prescription medication that you breathe directly into the lungs.
They are essential for asthma treatment and may be short-acting or long-acting.
These medications include inhaled corticosteroids and leukotriene modifiers.
Precautions and Contraindications
Antihistamines are generally considered safe.
Who Shouldnt Take Antihistamines?
Some people shouldn’t take antihistamines.
For example, people with known allergies or hypersensitivities to antihistamines should avoid them.
Certain medical conditions can make taking OTC or prescription antihistamines risky.
In addition, you should not take Xyzal if you have end-stage renal disease or are undergoing dialysis.
Doctors typically prescribe a lower antihistamine dose to those with any stage of kidney impairment or liver disease.
That’s because of an increased risk of toxicity.
Warning: Combination Allergy Medications
Antihistamines are available in combination allergy products withdecongestants, such as pseudoephedrine.
However, these medications can interact with other drugs and raise the risk of side effects.
So, consult a healthcare provider before taking a combination product.
Anticholinergics Risks
First-generation antihistamines (e.g., Benadryl, Ala-Hist IR) are considered anticholinergic drugs.
Anticholinergics can worsen certain conditions or lead to severe complications.
Dosage
Antihistamine dosage depends on the medication and may vary depending on your overall treatment plan.
OTC antihistamines commonly come in tablet, chewable, dissolvable, and syrup preparations.
Prescription medications, like Clarinex and Xyzal, typically come in tablets or syrup.
That’s because you may not clear antihistamines as efficiently, increasing the risk of toxicity.
Older adults are more likely to have impaired liver or kidney function and may benefit from lowered dosages.
People generally take second-generation antihistamines in the morning.
You should store most antihistamines at room temperature.
Read the product label for exact ranges to ensure they don’t get too warm or cold.
Side Effects
Antihistamines are typically well-tolerated.
However, they do carry the risk of side effects, especially first-generation antihistamines.
Side effects are also more likely when you take high doses of antihistamines.
Asthma medications, especially rescue inhalers, may also cause dizziness and amplify this antihistamine side effect.
Tell your healthcare provider if you feel dizzy after taking an antihistamine.
Your medication may need to be adjusted or changed if you have allergic asthma.
Sleepiness is more likely with first-generation than second-generation antihistamines for people of all ages.
Of course, it’s always worth consulting with your pharmacist about this as well.
Never assume that your doctor or pharmacist knows about the medications you take.
Summary
People use antihistamines to treat allergy symptoms.
They are not a first-line treatment for asthma, but they can help relieve allergy symptoms that trigger asthma.
In addition, antihistamines are sometimes combined with other medications to treat allergic asthma.
A doctor will need to assess your situation to determine if antihistamines fit into your asthma treatment plan.
First, they will determine which allergens trigger your asthma.
Then, they will help you avoid those allergens.
Antihistamines are generally safe, but they aren’t suitable for everyone.
If you have a known allergy to the drug, you should avoid taking it.
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