The local legislative body of each county is hereby authorized to create a county drug control authority. Such authority shall consist of not less than five nor more than nine members who shall be appointed by the county legislature or by the county executive in those counties where the county charter provides that members of county boards, commissions, authorities or agencies are to be appointed by the county executive, at least one of whom shall be a physician licensed to practice medicine in this state. Any person serving as a member of a county narcotic guidance council, drug abuse commission or mental health board shall be eligible to serve as a member of the board of a county drug authority created pursuant to this article. The chairman of the board shall be designated by the county legislature or by the county executive in those counties where the county charter provides that members of county boards, commissions, authorities or agencies are to be appointed by the county executive, from among the members so appointed. The compensation of the members shall be fixed by the county legislative body within the amount available therefor by appropriation. The board shall appoint a counsel, an administrative officer and such other officers, employees, agents and consultants as may be necessary, prescribe their duties, fix their compensation and provide for payment of their expenses, all within amounts appropriated therefor by the county.