The development of new technologies to monitor drugs concentration directly in patient’s blood is absolutely required to succeed in personalized drug therapies. In this study, Etoposide - a well-known anti-cancer drug - has been chosen as model for cyclic voltammetry detection of drugs. Carbon nanotubes are chosen as electron-transfer mediators to enhance the system sensitivity. A very low frequency and low slope triangular-wave potential is required to acquire cyclic voltammograms. Cyclic voltammograms are definitely needed for a correct identification and quantification of the drug concentration in the patient serum. The aim of the paper is to investigate the feasibility of VLSI fully-integration of cyclic voltammetry measurements as a tool to develop a low-cost chip for drug monitoring in personalized therapy. A triangular wave generator CMOS circuit is proposed by using Direct Digital Synthesis (DDS) method. The circuit is implemented in 0.18 μm technology and it presents the possibility of changing the slope of the triangular voltage in a wide range of 10 to 100mV/s.