Norfloxacin is well tolerated with a few adverse reactions. The most common adverse effects reported are nausea, vomiting, heartburn, constipation, diarrhoea, headache, dizziness, depression, insomnia and seizures; rash, dry mouth, fever, arthralgia and crystalluria. Nausea, vomiting, anorexia and a metallic or bitter taste in the mouth are the most common side effects. Malaise, vertigo, pruritus, headache, constipation and skin rashes have also been reported.