Allergic Reaction

• Many of those who take belladonna have an unexpected allergic reaction which causes swelling on the face and difficulty breathing. Those with such allergic reactions should avoid taking belladonna.
  
  

Heart Rate

• Belladonna can speed up the heart rate, making belladonna dangerous for those with heart conditions.
  
  

Rash

• Those who take belladonna sometimes develop a rash or flushing.
  
  

Eye Pain

• Eye pain is reported by some individuals who take belladonna.
  
  

Less Common Side Effects

• Other side effects that takers of belladonna might experience are headache, dizziness, lightheadedness, fatigue, anxiety, blurred vision, sensitivity to light, nausea, reduced sweating, constipation, urination problems and nasal stuffiness.
  
  

Warning

• Those who take belladonna should avoid drinking and operating heavy machinery, since this drug can cause drowsiness. Takers of belladonna should also avoid heat because of the reduced sweating caused by belladonna.