Parchilla - Allopurinol is a medication which inhibits the generation of uric acid in the cells, so that the concentration of uric acid in your blood is kept low and the urate crystals which cause gout won't form. Aspirin doesn't do that at all. It may ease the pain of a gout attack, but it may also increase the likelihood of a gout attack occurring because it makes the blood more acidic so that urate crystals are more likely to form.
At present, physicians who prescribe allopurinol view it as a life-long regimen, although some studies are being performed to see if after long-term usage the dosage can be reduced or even stopped.
It is quite possible that the immediate cause of your gout attacks was sleep apnea, which is the frequent cessation of breathing for many seconds at a time during sleep. The resulting reduction of oxygen in your blood makes the formation of urate crystals much more likely. Make sure that you don't have sleep apnea. If you do and you overcome it, you will it very likely find that you have no more gout attacks even with no allopurinol usage. More importantly, you will greatly reduce your risk for developing the life threatening consequences of sleep apnea -- heart disease, heart failure, heart arrhythmia, high blood pressure, diabetes, kidney disease, cancer, etc. Allopurinol does little to prevent those diseases.