Objective: To explore the role of blood concentration monitoring by clinical pharmacists in pharmaceutical care and identification of drug interactions through monitoring and intervening cyclosporine A (CsA) and rifampicin (RFP) in 3 patients with nephrotic syndrome (NS) complicated with tuberculosis infection. Methods: Blood concentration monitoring was used as a technical support to analyze the changes of CsA plasma concentration after combination with RFP and withdrawal of RFP

revealing the severity and duration of their interactions. Based on this

the pharmacists sought an effective treatment. Results: The plasma concentration of CsA didn’t rise to the effective concentration by taking multiple measures in combination with RFP. However

it rose to be effective after 7 days’ withdrawal of RFP

and the RFP induction still existed. These results indicated that RFP can significantly and persistently reduce the blood concentration of CsA

and the combined therapy should be avoided. Conclusion: Through blood drug concentration monitoring

pharmacists have participated in the optimization of drug treatment

successfully intervened the drug interaction

ensured the safety of patients

and promoted the rational drug use in clinic.