Computer implemented methods and systems for controlling the dispensation of a prescription drug to a patient with a medical condition. The methods and systems may restrict the prescription and dispensation of prescription drugs at the physician and pharmacy level. Determination of whether a patient should receive a subsequent prescription of a drug is based on the effectiveness of the drug and the adverse side effects associated with the drug. This can be used by state and federal regulators, physicians and pharmacists to control, evaluate and monitor the use of drugs on an individual patient basis. Furthermore, the methods and systems provide a national registry in which drug effectiveness data in individual patients is collected which can be aggregated to provide information on population-based drug efficacy.