Certain drugs, such as monoamine oxidase inhibitors, blood pressure medications, or ketoconazole, may interact with Claritin-D. Interactions with these medicines could increase the level of Claritin-D in your blood and increase your risk of developing side effects. Since drug interactions with Claritin-D are usually due to the pseudoephedrine component of the medication, regular Claritin (which does not contain pseudoephedrine) may be a better choice.
The following sections explain in detail the potentially negative interactions that can occur when Claritin-D is combined with any of the drugs listed above.
Blood Pressure Medications
Claritin-D may make blood pressure medications less effective, possibly causing high blood pressure (hypertension). This is due to the pseudoephedrine component of Claritin-D. If you take high blood pressure medications, check with your healthcare provider before taking Claritin-D or try regular Claritin instead, which does not contain pseudoephedrine and does not increase blood pressure.