This paper introduces an approach that combines molecular communication (MC) concepts with waveform modulation techniques to regulate drug concentrations at targeted lesion sites, aiming to enhance therapeutic outcomes and minimize side effects. We focus on keeping drug levels within the therapeutic window by grounding our method in MC theory. Our study is primarily the analytical process of selecting the most effective pathways in vascular networks, considering factors such as blood vessel characteristics and the frequency of their branching. This investigation is critical for a deeper understanding of the complexities of the dynamic nature of pathway selection in vascular networks and for seeking to refine drug administration based on these insights. Our research pinpoints the optimal timing for drug administration using continuous-release formulations, ensuring consistent locoregional drug concentrations. The simulations validate our approach, indicating its potential to maintain stable drug levels, thereby underscoring the importance of adapting to variations in the intravascular delivery pathway. Our method, which merges MC principles with waveform modulation, contributes a nuanced perspective on enhancing the precision of drug delivery, supporting the development of an effective and personalized treatment strategy.