Spain has allowed the medication derived from cannabis - the main ingredient in marijuana - for the treatment of spasticity in patients with multiple sclerosis.

Health Minister Trinidad Jimenez said the therapeutic use of cannabis has been studied for 'many years' and is well-documented in clinical trials.

The use of cannabis to ameliorate the symptoms of different diseases and conditions is a very controversial matter, but what is certain is that some patients with illnesses that involve substantial bodily pain resort to marijuana to mitigate their suffering, she said Wednesday.

People suffering from multiple sclerosis and experiencing moderate to severe muscle spasms can get a prescription for the cannabis-based drug, Sativex, which is administered as an oral aerosol.

The minister ruled out that the medical use of this drug will be extended to other ailments, for instance cancer.

She said this is about 'a very specific use, if other treatments have failed, if and when authorised by a (health) specialist and for a very reduced group of patients.'

'(It's prescription) could be studied if the medical specialist considers it to be appropriate and when other kinds of medications have failed, but it would be on a case-by-case basis and for a very controlled group of (patients),' she said.

Meanwhile, GW Pharmaceuticals has begun registration procedures for the approval of Sativex in European Union member countries, including the bloc's main markets of Germany, France and Italy.