Italian bottom brackets have both cups right hand threaded and the drive side cup has a natural tendency to unscrew unless torqued down VERY tight. The recommended installation torque is over 300 inch-pounds and you are unlikely to get it that tight unless you have a torque wrench to guide you.
Some mechanics use blue (Grade 242) Locktite on the threads which can be useful but shouldn't be necessary if the installation torque is sufficient.