Remimazolam (Byfavo®): A Comprehensive Pharmacological and Clinical Monograph

Section I: Drug Identity and Physicochemical Characteristics

1.1. Overview and Classification

Remimazolam is an ultra-short-acting intravenous (IV) benzodiazepine (BDZ) sedative and anesthetic agent.[1] It is classified as an imidazobenzodiazepine and was developed as a modern alternative to the widely used short-acting benzodiazepine, midazolam.[3] The defining characteristic of remimazolam is its classification as a "soft drug".[1] This pharmacological design concept involves creating a therapeutically active molecule that is intentionally engineered to be metabolically fragile. This fragility ensures rapid and predictable biotransformation into inactive metabolites within the body, leading to a swift termination of its pharmacological effects upon cessation of administration.[2]

This "soft drug" principle is the cornerstone of remimazolam's clinical value. The drug's name itself, "Remi-mazolam," was deliberately conceived by its developers to signal its therapeutic identity: it combines the well-understood sedative and amnestic properties of a benzodiazepine like midazolam with the ultra-short-acting pharmacokinetic profile of the opioid remifentanil, which is also metabolized by non-specific esterases.[6] This conceptual linkage underscores a sophisticated development strategy—applying a proven pharmacological design principle from one therapeutic class (opioids) to another (benzodiazepines) to address the well-documented clinical limitations of older agents, namely prolonged and unpredictable sedation.

1.2. Nomenclature and Identifiers

For clarity in research, clinical practice, and regulatory contexts, remimazolam is identified by a variety of names and codes.