Sick Queenslanders will have access to medicinal cannabis treatments after the passing of laws allowing doctors to apply to prescribe the drug on a much larger scale.

The legislation, passed unanimously on Wednesday night, opened up a legitimate pathway for patients with certain types of illness to access the treatment.

Doctors will be able to apply to prescribe cannabis.

Regulatory changes introduced last year allowed individuals to apply for treatment but only one person had been approved to date.

A Logan family's "long and at times frustrating" battle to get treatment for their son was highlighted in the lead-up to the bill's passage.