What is the definition of toxicology?

The definition of toxicology is indeed focused on the investigation of poisons and their effects on living organisms. This field emphasizes understanding how various substances can cause harm, the mechanisms by which they operate, and the resulting physiological effects on the body. Toxicology encompasses a wide range of harmful substances, including environmental toxins, drugs in excessive amounts, and naturally occurring poisons.

The other options, while related to medicine and health, do not capture the essence of toxicology. The study of drug interactions pertains specifically to how different medications affect one another, rather than focusing on toxicity. The study of therapeutic drugs is concerned with medications used for treatment rather than their potential harmful effects. Lastly, the study of patient psychology examines mental processes and behaviors, which is outside the scope of toxicology's primary focus on harmful substances.