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.