Who Cannot Take Claritin? Essential Safety Information

October 5, 2025 •

4 min read

According to a study in StatPearls, while loratadine, the active ingredient in Claritin, is a safe and effective allergy medication for many, certain individuals must exercise caution or avoid it entirely due to pre-existing conditions, specific drug interactions, or age. It is crucial to understand who cannot take Claritin to ensure safe and effective use.

Quick Summary

Certain individuals with specific health conditions, such as severe kidney or liver disease, and those on interacting medications should avoid or modify Claritin use. Claritin-D, a different formulation, has more restrictions.

Key Points

Known Allergy to Loratadine: Individuals with a documented allergy or hypersensitivity to loratadine or its components should not take Claritin under any circumstances.
Severe Liver or Kidney Disease: Patients with severe liver or kidney impairment should consult a doctor, as they may require a reduced dosage or be advised to avoid the medication due to impaired drug clearance.
Claritin-D Specific Conditions: The combination product Claritin-D (containing pseudoephedrine) is not suitable for people with severe high blood pressure, coronary artery disease, narrow-angle glaucoma, or those taking MAOIs.
Children Under 2: Children under the age of 2 should not be given Claritin without a doctor's recommendation.
Drug Interactions: Exercise caution when taking Claritin with alcohol, other antihistamines, or CNS depressants due to increased drowsiness. Some antibiotics and antifungals can also interfere with loratadine metabolism.
Phenylketonuria (PKU): Certain formulations, like orally disintegrating tablets, contain phenylalanine and should be avoided by individuals with PKU.
Pregnancy and Breastfeeding: While generally safe, pregnant and breastfeeding individuals should consult a healthcare provider before using Claritin, and be aware that Claritin-D can affect milk supply.

Before starting any new medication, including over-the-counter options like Claritin, it is crucial to consult with a healthcare provider. While Claritin (loratadine) is generally considered a safe and non-drowsy antihistamine for most people, certain health conditions, ages, and co-administered substances can make its use risky or require modification. Understanding these specific situations is essential for your safety.

Absolute Contraindications: Allergies and Age

Certain groups should not take Claritin under any circumstances due to the risk of severe reactions:

Hypersensitivity: Anyone with a documented allergy or hypersensitivity to loratadine or desloratadine (an active metabolite of loratadine) should not take Claritin. An allergic reaction could manifest as a rash, hives, or swelling of the face, tongue, or throat.
Children Under 2: Claritin should not be given to children under the age of 2 without consulting a doctor. The manufacturer's instructions for Children's Claritin specify usage for ages 2 and up, with varying dosages for different age ranges.
Phenylketonuria (PKU): People with PKU must be aware that some orally disintegrating tablet (ODT) formulations of Claritin contain phenylalanine. PKU patients should always discuss medication options with their doctor before use.

Medical Conditions Requiring Caution or Dose Adjustment

Individuals with certain health conditions need to speak with a healthcare provider before using Claritin, as the medication is processed by the liver and kidneys. This is particularly important for patients with:

Liver Disease: For individuals with liver impairment, the body may not be able to clear loratadine as efficiently, which can lead to a buildup of the drug and increased risk of side effects. A doctor may recommend a reduced dose, such as taking the medication every other day, in cases of severe liver disease.
Kidney Disease: Similar to liver disease, those with decreased kidney function (creatinine clearance less than 30 mL/min) have a reduced clearance of loratadine. A doctor may adjust the dosage, as recommended by manufacturers, to prevent adverse effects from accumulation.
Asthma/COPD: Patients with asthma or chronic obstructive pulmonary disease (COPD) should use loratadine with caution due to its mild anticholinergic effects, which could potentially cause a flare-up.

Important Drug and Substance Interactions

Taking Claritin with other substances or medications can increase the risk of side effects. It is vital to consider all drugs and supplements you are taking.

Alcohol and CNS Depressants: Combining Claritin with alcohol or other central nervous system (CNS) depressants, including opioids, sleeping pills, or sedatives, can significantly increase drowsiness and dizziness.
Other Oral Antihistamines: Using Claritin with other oral antihistamines like Benadryl (diphenhydramine) is not recommended as it increases the risk of side effects like dry mouth, constipation, and excessive drowsiness.
Certain Antibiotics and Antifungals: Medications like erythromycin and ketoconazole can inhibit the body's ability to eliminate loratadine, leading to higher concentrations of the drug in the blood and increased potential for side effects.
Herbal Supplements and Other Drugs: Blood levels of loratadine can also be affected by supplements like St. John's Wort and other medications such as cimetidine, carbamazepine, and rifampin.

Claritin-D: Specific Health Concerns

The combination product Claritin-D contains both the antihistamine loratadine and the decongestant pseudoephedrine. The presence of pseudoephedrine adds a significant list of contraindications and warnings.

Claritin vs. Claritin-D: Contraindications at a Glance


Condition / Factor	Regular Claritin (Loratadine)	Claritin-D (Loratadine + Pseudoephedrine)
Allergy to Ingredients	Contraindicated	Contraindicated
Severe Liver Disease	Dose adjustment advised	Avoid use
Severe Kidney Disease	Dose adjustment advised	Use with caution, dose adjustment needed
Hypertension (High Blood Pressure)	Generally safe	Contraindicated for severe cases; caution for others
Severe Heart Disease	Generally safe	Contraindicated for severe cases; caution for ischemic heart disease
Glaucoma (Narrow-Angle)	Generally safe	Contraindicated
Urinary Retention	Generally safe	Contraindicated
MAOI Therapy	Safe to use	Contraindicated during and within 14 days of MAOI therapy
Pregnancy	Generally safe, but consult doctor	Avoid during certain stages; consult doctor
Breastfeeding	Generally safe, but monitor infant; may pass into milk	May reduce milk supply; use with caution
Children Under 12	Consult a doctor for ages 2-6; safe for 6+	Safety and efficacy not established

Special Considerations for Specific Populations

The Elderly: Seniors may be more sensitive to the side effects of medications, even non-drowsy antihistamines. Side effects such as dizziness, confusion, and urinary issues can be more pronounced in older adults, increasing the risk of falls. For older adults, non-drowsy antihistamines like Claritin are typically preferred over older generations like Benadryl.
Pregnancy and Breastfeeding: While Claritin is generally considered safe during pregnancy, and studies show no increased risk of congenital abnormalities, it is still best to discuss with a healthcare provider. For breastfeeding mothers, a small amount of loratadine passes into breast milk. While typically safe for the infant, it's wise to use minimal doses for short periods and to watch for any infant drowsiness or irritability. Claritin-D, however, should be used with extreme caution or avoided, as the pseudoephedrine component can reduce milk supply.

Conclusion

Claritin is an effective allergy medication for many, but it is not universally safe. Individuals with documented hypersensitivity to its components should not take it. Furthermore, certain underlying health issues like severe liver or kidney disease necessitate medical consultation and possible dose adjustments. The combined formula, Claritin-D, has additional restrictions related to its decongestant ingredient, making it unsuitable for those with high blood pressure, heart disease, or glaucoma. For special populations such as children under 2, the elderly, and those pregnant or breastfeeding, a doctor's guidance is essential. Acknowledging these limitations and consulting a healthcare professional are vital steps for ensuring safety and efficacy when using Claritin.

Frequently Asked Questions

It is not recommended to take Claritin with other oral antihistamines, especially older, sedating ones like Benadryl, to avoid heightened side effects such as drowsiness and dry mouth. If you are taking a combination product, like a "nighttime" cold medicine, check the label to ensure it doesn't contain an antihistamine.

Regular Claritin (loratadine) is not typically known to increase blood pressure and is often a safer option for those with hypertension. However, Claritin-D, which contains the decongestant pseudoephedrine, can cause an increase in blood pressure and is contraindicated in severe cases.

If you take more than the recommended dose, you may experience increased side effects like fatigue or headaches. In case of a suspected overdose, it's best to contact a poison control center immediately or seek emergency medical help if serious symptoms occur.

Claritin is generally safer for older adults than first-generation antihistamines like Benadryl because it is less likely to cause side effects such as confusion, dizziness, and sedation. However, seniors should still use caution and consult a healthcare provider, as they may be more sensitive to medication side effects.

Alcohol can increase the risk of drowsiness when combined with Claritin. Some sources also suggest that taking antihistamines on an empty stomach might improve absorption, but unlike Allegra, Claritin is not significantly affected by grapefruit juice.

Yes, regular Claritin is generally considered safe for breastfeeding mothers, as only a small amount passes into breast milk. However, a healthcare provider should be consulted. Importantly, Claritin-D should be used with caution as its decongestant component may reduce milk supply.

Yes, antihistamines can interfere with the results of an allergy skin test. You may need to stop taking Claritin for several days before the test; always follow your doctor's instructions.