Thank you for using Doctor Spring for posting your query. 1. Rasalect is a tablet containing the chemical compound Rasagiline. It is used to treat Parkinson Disease. Parkinson disease is a common neurological disease usually affecting those aged 60 years and above. It is characterised by slowness of movements, fine shaking of hands at rest, difficulty walking, constipation, depression etc. 2. Lesuride contains Levosulpiride which is commonly used as a prokinetic agent, that is increases the movements of the gut and fastens movement of food from the stomach. It is usually used in constipation predominant-Irritable Bowel Syndrome. It can also be used in anxiety disorders, etc. 3. Cremalax is a laxative containing Lactulose. This is used for constipation. 4. Zolfresh contains Zolpidem which is a sedative. It is given to persons suffering from sleeplessness. Conclusion- It appears that your father may be having Parkinson Disease for which he is taking Rasalect 0.5mg. since Parkinsons commonly causes constipation, he has been prescribed Lesuride and Cremalax. Zolpidem 5mg is to treat his sleeplessness. I hope this helps. Feel free to ask follow ups. Thank you.