Greetings ! Welcome to the site. Well the switch over from one psychotropic medication to another is always tricky since it may precipitate what is called as withdrawal syndrome / side effects if the switch over is too fast without proper tapering of the first drug followed by introduction of the second one after the first drug has been discontinued. These withdrawal symptoms / side effects although reversible and temporary but they are distressing enough to make matters once albeit for a short period until they last. So a similar situation is at hand in your son s case here, so I reckon that you may use the strategy of Cross- titration under the supervision of his doctor where you from tomorrow onwards till next 10 days continue to give Geodon at 20 mg but at alternative day so that in the next 10 days he gets 5 doses. Simultaneously from tomorrow you shall introduce risperidone at 0.5 mg dose which is to be continued for the next 10 days during the cross-titration period and once after 10 days when Geodon is topped completely then you may consider raising the dose of risperidone to a dose which is discussed and agreeable with his doctor. Prozac is to be continued as it is without any change. As of now for today no risperidone is to be given. So this is how a proper strategic cross-titration switch over is carried out that ensures a safe transition from one drug to another mitigating the risk of withdrawal side effects all along. I hope this helps. Wish your son all the best. Take care. Regards..