What is Clarinex-D 12 Hour: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

Clarinex-D 12 Hour overview

BRAND NAMES:

  • Clarinex-D, CLARINEX-D 12 HOUR, Clarinex-D 24HR

Generic Names:

  • Clarinex-D 12 Hour

Uses:

  • Treats symptoms of seasonal allergies. This medicine contains an antihistamine and a decongestant.

Therapeutic Classes:

  • Antihistamine, Less-Sedating/Decongestant Combination

Forms:

  • 24 Hour Tablet, 12 Hour Tablet

How it’s taken:

  • By mouth

What is Clarinex-D 12 Hour used for?

What form(s) does Clarinex-D 12 Hour come in

  • 24 Hour Tablet

  • 12 Hour Tablet

What are common Clarinex-D 12 Hour doses?

  • Tablet 2.5mg/120mg

Common Clarinex-D 12 Hour prescriptions

  • Clarinex-D 12 Hour
    2.5mg/120mg tablet

  • Clarinex-D 12 Hour
    2.5-120mg tablet extended release 12 hour

How to take Clarinex-D 12 Hour

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

  • Swallow the extended-release tablet whole. Do not crush, break, or chew it.

  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.

  • Your doctor will tell you how much medicine to use. Do not use more than directed.

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

What to do if you miss a dose of Clarinex-D 12 Hour

Clarinex-D 12 Hour contraindications

  • This medicine is not right for everyone. Do not use it if you had an allergic reaction to desloratadine, pseudoephedrine, or loratadine, or if you have narrow-angle glaucoma, severe heart disease, severe high blood pressure, or problems urinating.

Clarinex-D 12 Hour warnings

  • Tell your doctor if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, diabetes, high blood pressure, heart disease, glaucoma, thyroid problems, or prostate problems.

  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

  • Lightheadedness, dizziness, fainting

  • Severe nervousness or restlessness, tremors, seizures

Clarinex-D 12 Hour interactions

  • Some medicines can affect how this medicine works. Tell your doctor if you are also using any of the following: DigitalisReserpineMedicine to lower blood pressure

  • Do not use other antihistamine or decongestant medicines with this medicine, including ones you can buy without a prescription.

  • Do not use this medicine if you have used an MAO inhibitor in the past 14 days.

Clarinex-D 12 Hour side effects

Serious Side Effects

  • Severe nervousness or restlessness, tremors, seizures

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing

  • Fast, pounding, or uneven heartbeat

  • Lightheadedness, dizziness, fainting

Less Serious Side Effects

  • Headache

  • Trouble sleeping

  • Dry mouth

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