After Massachusetts voters passed a ballot initiative on Tuesday legalizing the use of marijuana for medical purposes, I’m wondering how the law will be implemented, as my colleague Chelsea Conaboy details the challenges in today’s Globe.

The state’s Department of Public Health will follow the lead of other states and require patients to get a physician’s approval to apply for a medical marijuana identification card. This card will enable them to obtain and possess a certain amount of the drug from a state dispensary if they have a debilitating condition.