Receives prescriptions, checks patients' medicine histories, and ensures optimal dosage and methods of administration and drug compatibility before dispensing prepares or supervises the preparation and labelling of liquid medicines, ointments, powders, tablets and other medications to fill prescriptions advises patients on drug incompatibility and contra-indications maintains prescription files and records issue of narcotics, poisons and habit-forming drugs stores and preserves vaccines, serums and other drugs subject to deterioration supplies non-prescription medicines, and diagnostic and therapeutic aids supervises and co-ordinates the work of pharmacy technicians, pharmacy interns and pharmacy sales assistants.