The medicinal chemistry approach can be applied to develop new treatments for viral infections resistant to currently available antiviral drugs through the following steps:1. Target identification and validation: The first step is to identify and validate new molecular targets that are essential for the replication and survival of the virus. These targets can be viral proteins, host proteins, or other cellular components that are hijacked by the virus during infection. Target validation involves confirming the importance of the target in the viral life cycle and its potential as a therapeutic target.2. Hit identification: Once a target has been identified and validated, the next step is to find small molecules or biologics that can interact with the target and inhibit its function. This can be done through various techniques such as high-throughput screening, fragment-based drug discovery, or virtual screening using computational methods.3. Hit-to-lead optimization: After identifying potential hits, medicinal chemists optimize these compounds to improve their potency, selectivity, and drug-like properties. This involves synthesizing and testing a series of analogs with modifications in their chemical structure to identify the most promising lead compounds.4. Lead optimization: The lead compounds are further optimized to improve their pharmacokinetic properties, such as absorption, distribution, metabolism, excretion, and toxicity ADMET . This step involves iterative cycles of medicinal chemistry, in vitro testing, and in vivo studies in animal models to identify the most promising drug candidates.5. Preclinical development: Once a drug candidate has been identified, it undergoes extensive preclinical testing to evaluate its safety, efficacy, and pharmacokinetic properties in animal models. This includes studies on pharmacodynamics, toxicology, and drug metabolism.6. Clinical development: If the preclinical data are promising, the drug candidate enters clinical trials, where it is tested in humans for safety, tolerability, and efficacy. Clinical trials are conducted in multiple phases Phase I, II, and III to assess the drug's safety and effectiveness in treating the viral infection.7. Regulatory approval and post-marketing surveillance: If the drug candidate demonstrates safety and efficacy in clinical trials, it can be submitted for regulatory approval. Once approved, the drug can be marketed for the treatment of the viral infection. Post-marketing surveillance is conducted to monitor the drug's safety and efficacy in the real-world setting.Throughout this process, medicinal chemists collaborate with virologists, pharmacologists, toxicologists, and other experts to ensure the development of safe and effective antiviral drugs. By targeting novel molecular targets and employing innovative drug discovery techniques, medicinal chemistry can contribute to the development of new treatments for viral infections that are resistant to currently available antiviral drugs.