Systems and methods for monitoring and regulating the concentration of a drug in a subject are provided. A method may include administering to a subject a first dose of a pharmaceutical composition at a first time point. Next a concentration of an active ingredient of the pharmaceutical composition or a metabolite thereof or a biological marker indicative of the concentration of the pharmaceutical composition in the subject may be determined from a biological sample of the subject with the aid of a point of care system. A second dose of the pharmaceutical composition may be administered to the subject at a second time point. The second dose and/or the interval between the first and second time points may be determined based on the concentration of the pharmaceutical composition in the subject.
