Drowsiness

• Claritin-D 24-hour is not supposed to cause drowsiness as one of its side effects; however, taking more than the recommended dosage may lead to drowsiness. Only one dose should be taken every 24 hours.
  
  

Dizziness

• Claritin-D 24-hour tablets may cause dizziness. Dizziness may be intensified by other medications or alcohol consumption.
  
  

Dry Mouth

• Claritin-D 24-hour may cause dry mouth. Consequently, unusual thirst may be experienced.
  
  

Stomach Symptoms

• This medication may cause nausea. Also, appetite may be decreased. In addition, stomach upset may occur.
  
  

Other Symptoms

• Some individuals may experience excitability, or they may feel nervous. Sleeplessness may also be experienced. Also, some may have headaches or a sore throat. Fatigue may also occur.
  
  

Allergic Reactions

• If an allergic reaction occurs, medical attention should be sought right away. Allergic reactions may include difficulty breathing, chest pain or tightness, hives, rash, itching, facial swelling, tongue swelling, irregular or fast heartbeat, extreme dizziness and seizure.