A rapid and noninvasive method based on surfaceenhanced Raman spectroscopy （SERS) was developed to diagnose congestion degree of coronary arteries prospectively by detecting plateletderived growth factorBB （PDGF-BB) in urine samples in our previous research. This work was to investigate whether the developed method could be applied to the patients on longterm medication including aspirin, rosuvastatin, clopidogrel bisulfate,  and postPCI patients for the  diagnosis of congestion degree of coronary arteries. Firstly, urine samples from 13 patients on longterm medication  and from 13 postPCI patients were measured based on the developed method. It was found that there was no Raman peak at 1 509 cm^-1 attributed to PDGFBB in these SERS spectra. In addition, further investigation of SERS spectra of aqueous solutions of PDGF-BB mixed with three kinds of drugs was conducted. There was no Raman peak at 1 509 cm^-1 in these three spectra as well. It turned out that these drugs had impact on the SERS signal of PDGFBB, and this method was not suitable for the detection of congestion degree of coronary arteries for patients on longterm medication and postPCI patients.