Cenforce, a medication containing sildenafil citrate used to treat erectile dysfunction, can cause allergic reactions in some individuals. The first signs of an allergic reaction to Cenforce typically include skin-related symptoms such as rash, itching, or hives. These may appear shortly after ingestion. Swelling of the face, lips, tongue, or throat is also a serious early indicator, often accompanied by difficulty breathing or swallowing. Other symptoms might include dizziness, nausea, or a rapid heartbeat. In rare cases, severe reactions like anaphylaxis can occur, requiring immediate medical attention. If any of these signs emerge, stop using the medication and seek emergency care immediately.