An allergic reaction to Cenforce 100 mg (sildenafil) is uncommon but can be serious. Symptoms may appear shortly after taking the medicine and can include:

Skin symptoms: sudden rash, hives, itching, redness, or swelling.

Facial swelling: swelling of the lips, tongue, face, eyelids, or throat.

Breathing problems: wheezing, shortness of breath, difficulty breathing, or tightness in the throat or chest.

Swallowing difficulties: trouble swallowing or a feeling that the throat is closing.

Severe dizziness or fainting: particularly if accompanied by weakness or breathing difficulties.

Rapid or unusual heartbeat may occur with a severe reaction.

A particularly dangerous allergic reaction is anaphylaxis, which can develop rapidly and requires emergency medical treatment. If you experience difficulty breathing, throat or tongue swelling, severe dizziness, or fainting after taking Cenforce 100 mg, seek emergency medical care immediately rather than taking another dose.

Not every side effect is an allergy. Headache, flushing, indigestion, nasal congestion, and mild dizziness are recognized sildenafil side effects and do not necessarily indicate an allergic reaction.

If you develop a new rash, itching, or swelling after taking sildenafil, stop using it and contact a healthcare professional for advice before taking another dose.