Side effects of generic Alfuzosin tablets may include hives; difficulty breathing; swelling of your face, lips, tongue, or throat. Serious side effects may include new or worsening chest pain; nausea, stomach pain, low fever, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes); feeling like you might pass out; or penis erection that is painful or lasts 4 hours or longer. Less serious side effects may include dizziness or drowsiness; headache, tired feeling; warmth, redness, or tingly feeling under your skin; mild stomach pain, diarrhea, constipation; or sore throat, cough, runny or stuffy nose. For further information talk with your local doctor about possible side effects.