Skip to Content

Clarinex-D 12 Hour Side Effects

Generic Name: desloratadine / pseudoephedrine

Note: This page contains information about the side effects of desloratadine / pseudoephedrine. Some of the dosage forms included on this document may not apply to the brand name Clarinex-D 12 Hour.

In Summary

More frequent side effects include: headache, insomnia, and xerostomia. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to desloratadine / pseudoephedrine: oral tablet extended release 12 hr, oral tablet extended release 24 hr

In addition to its needed effects, some unwanted effects may be caused by desloratadine / pseudoephedrine. In the event that any of these side effects do occur, they may require medical attention.

Major Side Effects

You should check with your doctor immediately if any of these side effects occur when taking desloratadine / pseudoephedrine:

Observed during clinical practice
  • Abdominal or stomach pain area
  • chills
  • clay-colored stools
  • cough
  • dark urine
  • difficult or labored breathing
  • difficulty swallowing
  • dizziness
  • elevated liver enzymes
  • fast heartbeat
  • fast, pounding, or irregular heartbeat or pulse
  • fever
  • general tiredness and weakness
  • headache
  • hives
  • irregular heartbeat
  • itching
  • light-colored stools
  • loss of appetite
  • nausea
  • puffiness or swelling of the eyelids or around the eyes, face, lips or tongue
  • rash
  • redness of skin
  • shortness of breath
  • skin rash
  • swelling
  • tightness in chest
  • unpleasant breath odor
  • unusual tiredness or weakness
  • upper right abdominal pain
  • vomiting of blood
  • vomiting
  • welts
  • wheezing
  • yellow eyes or skin
Symptoms of overdose:

If any of the following symptoms of overdose occur while taking desloratadine / pseudoephedrine, get emergency help immediately:

  • Increased heart rate
  • sleepiness or unusual drowsiness

Minor Side Effects

Some of the side effects that can occur with desloratadine / pseudoephedrine may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common:
  • Dry mouth
  • sleeplessness
  • trouble sleeping
  • unable to sleep
Less common:
  • Body aches or pain
  • congestion
  • dryness or soreness of throat
  • hoarseness
  • nervousness
  • restlessness
  • runny nose
  • sleepiness or unusual drowsiness
  • tender, swollen glands in neck
  • trouble sitting still
  • voice changes
  • weight loss

For Healthcare Professionals

Applies to desloratadine / pseudoephedrine: oral tablet extended release


Cardiovascular side effects have included tachycardia and palpitations.[Ref]


Hypersensitivity side effects have included rash, pruritus, urticaria, edema, dyspnea, and anaphylaxis.[Ref]

Nervous system

Nervous system side effects have included headache, insomnia, somnolence, dizziness, and hyperactivity.[Ref]


Hepatic side effects have included elevated liver enzymes including bilirubin and very rarely hepatitis.[Ref]


Gastrointestinal side effects have included nausea and anorexia.[Ref]


General side effects have included dry mouth, fatigue and pharyngitis.[Ref]


1. "Product Information. Clarinex-D 24 Hour (desloratadine-pseudoephedrine)." Schering-Plough Corporation, Kenilworth, NJ.

Not all side effects for Clarinex-D 12 Hour may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.