It is a rare drug allergy but is life-threatening. It can occur few minutes to few hours after the medication. Fortunately it is very rare.

The common symptoms include:

• Rapid drop in blood pressure
• Rapid or weak pulse
• Rapid or pounding heartbeats
• Difficulty in breathing
• Wheezing
• Hives
• Dizziness or fainting
• Nausea
• Vomiting
• Abdominal cramps
• Diarrhoea
• Swelling in the face

It may be difficult to diagnose because the time of the allergic reaction is different always. If the symptoms are there it is better to rush to your doctor or to the emergency station of a hospital.

Your doctor injects adrenaline, antihistamines or cortisone to stop hives, itching and inflammation.