Common Side Effects

• According to the Mayo Clinic, side effects of Diovan that are considered common but not serious include back or abdominal pain, flu-like symptoms, coughing, headache, mild fatigue and minor swelling in the patient's joints.
  
  

Serious Side Effects

• Serious side effects include vomiting, weight gain, chills or fever, darkened urine and hoarseness. A patient experiencing these symptoms should consult with a physician before continuing Diovan doses.
  
  

Severe Side Effects

• Severe side effects that require immediate medical attention include blood in urine, confusion, sudden difficulty breathing or swallowing, increased thirst, irregular heartbeat and swelling of the face, tongue or extremities.
  
  

Existing Medical Conditions

• According to PDRHealth, before using Diovan, a patient should advise her physician of existing medical conditions such as allergies to foods or animal dander. Diovan may cause birth defects, so women who are pregnant or plan to become pregnant should not take this medication.
  
  

Drug Interactions

• According to PDRHealth, Diovan has the potential to adversely interact with potassium supplements, potassium-sparing diuretics, salt substitutes, lithium and nonsteroidal anti-inflammatory drugs (NSAIDs).