More Common Side Effects

• Meclizine HCl, like other antihistamines, can cause blurred vision, drowsiness, dry mouth, fatigue, headaches, nervousness, sore throat and thickening of bronchial mucus.
  
  

Gastrointestinal Side Effects

• Possible gastrointestinal side effects include abdominal pain, diarrhea, increased appetite, weight gain, and worsening of gastroesophageal reflux disease and stomach ulcers.
  
  

Rare Side Effects

• Serious side effects are rare, and more common in young children and elderly people. They include heart palpitations, irregular heartbeat, rapid heartbeat, confusion, difficulty urinating, seizures and worsening of glaucoma.
  
  

Allergic Reaction

• Rarely, some people can have an allergic reaction to meclizine HCl. Signs are rash or hives, itching, swelling of the throat or mouth, wheezing and difficulty breathing.
  
  

Drug Interactions

• Meclizine HCl may interact with alcohol, certain high blood pressure medications, anti-cholinergic drugs, antipsychotic medications, anti-anxiety medications, anti-depressants, muscle relaxants, narcotic pain relievers and sleep medications.