The U.K.'s primary medical regulatory body has approved a cannabis-derived spray for treatment of spasticity in multiple-sclerosis patients, Reuters reported June 18. 

The drug, Sativex, was the first marijuana-based medication to be cleared for prescription use in Canada, where it has been used to treat neuropathic pain since 2005. 

The next step in the U.K. rests with the National Institute for Health and Clinical Excellence (NICE), which will decide if the drug can be paid for by the National Health Service.

Experts now expect Sativex to clear regulatory hurdles in Spain, followed shortly by the rest of Europe.

Sativex's manufacturer, GW Pharmaceuticals Plc, wants to broaden the drug's use to treat cancer pain, but marketing approval for that application is expected no sooner than 2013.