Colombia became on Tuesday the latest in a growing number of nations around the world to legalise the use of cannabis for medical reasons.

However the rules vary widely across continents, with some countries permitting cultivation and others only allowing pharmaceuticals extracted from the drug.

A state of play:

LATIN AMERICA

- COLOMBIA: President Juan Manuel Santos signed a decree Tuesday making it fully legal to grow, process, import and export cannabis and its derivatives for and scientific use.

- CHILE: Chile said in October it plans to allow the sale of marijuana-derived medication in pharmacies. The measure requires strict oversight, including authorisation by a specialist and inventory checks.

- MEXICO: An eight-year-old girl who endures 400 daily epileptic seizures became in September Mexico's first authorised consumer of imported after the government granted her an exemption to its marijuana ban.

- URUGUAY: Uruguay in December 2013 became the first country in the world to fully legalise marijuana all the way from the cannabis field to the joint, setting up a regulated market for cultivation, sales and use.

NORTH AMERICA

- THE UNITED STATES: Federal law bans the cultivation, the sale and use of marijuana. However, twenty-three US states allow medical marijuana use while four states—Oregon, Colorado, Alaska and Washington—plus the US capital city have legalised its recreational use.

- CANADA: Cannabis consumption for medical reasons has been legal since 2001. In June 2015, the Supreme Court expanded the definition of to allow authorised users to bake it into cookies and brew leaves for tea, in addition to smoking it.

EUROPE

- CROATIA: In October Croatia became the 13th European Union country to allow the medical use of cannabis. Medicines containing tetrahydrocannabinol (THC), the plant's main psychoactive ingredient, can now be prescribed by doctors to ease health problems associated with cancer, multiple sclerosis, epilepsy and AIDS.

- Austria, Britain, the Czech Republic, Finland, France, Germany, Italy, the Netherlands, Portugal, Romania, Slovenia and Spain already authorised cannabis-derived products to help treat certain illnesses.

© 2015 AFP