Drug transdermal delivery by electrophonophoresis can increase the concentration of rifampicin in the pleural effusion of patients with tuberculous pleurisy but has no effect on the concentration of rifampicin in plasma.

BACKGROUND

Electrophonophoresis (EP) has been widely used in various clinical fields. The purpose of this study was to evaluate the dermal permeability of rifampicin (RIF) in patients with tuberculous pleurisy assisted by EP and to verify the clinical application of this percutaneous drug delivery system in the treatment of tuberculous pleurisy, verify the system's influencing factors, and determine whether plasma drug concentration was increased.

METHOD: Patients were given oral isoniazid 0.3-0.4 g, rifampicin 0.45-0.60 g, pyrazinamide 1.0-1.5 g and ethambutol 0.75 g according to their body weight once a day. After 5 days of anti-tuberculosis treatment, 3 ml of rifampicin was delivered transdermally with EP. Pleural effusion and peripheral blood samples in patients were collected at and after dosing. The drug concentration in the samples was determined by high-performance liquid chromatography.

RESULT: The median plasma concentration (interquartile ranges) of RIF in 32 patients was 8.80 (6.65, 13.14) μg/ml before RIF transdermal injection plus EP and decreased to 8.09 (5.58, 11.82) μg/ml after 30 min of RIF transdermal injection plus EP. The RIF concentration in pleural effusion was higher than that before RIF-transdermal plus EP. In patients who received RIF via EP transdermal administration, the concentration of the drug at the local site was statistically higher than the concentration at the local site prior to penetration. However, no such enhancement was observed in plasma after transdermal administration of RIF.

CONCLUSION

EP can effectively increase the concentration of rifampicin in the pleural effusion of tuberculous pleurisy and has no effect on the circulating plasma concentration. The increased concentration of the drug in the lesion helps to destroy the bacteria.