Some medications can stop you sleeping, e.g. Amantadine and Selegeline, particularly if taken after 12pm. Strangely, some of the more 'sedating' meds can induce insomnia for some people... (agonists for example). Please be care with using sedating antihistamines (from the chemist), as they could interfere with your meds.... talk to your consultant / nurse about this. Could it be work stress?? Hope this helps.