The credentials you need to become a dispensary nurse at the clinic include a nursing degree and license. You will begin your career by receiving a post-secondary diploma, associate degree, or bachelor’s degree in nursing and passing the licensing examination of your state to become a registered nurse (RN) or licensed practical nurse (LPN). While this is not compulsory, you can also learn specialized skills by taking courses from the American Association of Marijuana Nursing (ACNA). Nurses employed in methadone clinics would need to register with the DEA and their state before beginning their work. It is helpful to have experience with chronic pain or related problems.