Drugs can be classified by which of the following?

Drugs can indeed be classified through multiple criteria, which include both their mechanism of action and their therapeutic effects. The mechanism of action refers to how a drug produces its effects at the molecular or cellular level, which is crucial for understanding its pharmacological properties and how it interacts with biological systems. For instance, drugs that inhibit specific enzymes or receptors can be grouped based on these actions.

Therapeutic action, on the other hand, categorizes drugs based on the condition or disease they are used to treat. For instance, analgesics are classified as pain relievers, and antibiotics are classified as agents that fight bacterial infections. This classification helps healthcare professionals select appropriate treatments based on a patient's specific medical condition.

Both classifications are vital for pharmacology and clinical practice since they guide the selection of drugs for therapy, predict their effects, and understand potential side effects. While medical history is important for selecting appropriate treatment for patients, it does not serve as a classification for the drugs themselves. Therefore, the inclusion of both mechanisms and therapeutic actions as bases for classification supports the notion that a comprehensive understanding of drugs necessitates evaluating various perspectives, reaffirming that all of the above criteria collectively contribute to drug classification, making the correct answer comprehensive.