Forty thousand users and counting: science-based nomenclature takes off

We often prescribe “antidepressants” for anxiety and “antipsychotics” for depression, Joseph Zohar (Tel Aviv University, Israel) told an ECNP 2020 Virtual symposium on Neuroscience-based Nomenclature.  Using the old way of classifying drugs confuses and distresses patients and – for clinicians – does not encourage a logical approach to treatment. Hence the need for a system based on our increased understanding of what is actually happening in the brain.

In taking this step, psychiatry is catching up with other areas of medicine such as hypertension where an augmentation strategy, for example, is based on addition of an agent with a different mechanism of action.

Multiple modes of action and use across indications have undermined a sixty year-old classification

American Psychiatric Association endorses NbN

The building blocks of the new system are ten pharmacological domains based on the neurotransmitter, molecule or system being modified (acetylcholine, dopamine, GABA, glutamate, histamine, orexin, melatonin, norepinephrine, opioid, serotonin) and nine modes of action (receptor agonist, partial agonist or antagonist; reuptake inhibitor; releaser; enzyme inhibitor, ion channel blocker; positive allosteric modulator; enzyme modulator).

According to a recent position statement of the APA,¹ positive features of the project include

• Potential for improved patient acceptance of medication recommendations
• Harmonization of psychiatry with other specialties which classify drugs by mechanism of action
• Avoidance of non-scientific terminology such as “major and minor tranquilizers” or “second generation antipsychotics”
• A teaching tool that presents the depth and richness of our knowledge of neuroscience.

NbN  helps the prescriber decide the rational next step to take

 New terms for old

The APA also hopes that more nuanced prescribing and precision medicine will be encouraged by the fact that the NbN reveals sixty different types of agent that differ from each other in pharmacological domain and/or mode of action.

The disease-based class of “antipsychotics”, which were also known as major tranquillizers, was subdivided into first and second generation agents. Under NbN, we have agents classified, for example, as a dopamine and serotonin receptor partial agonist (D₂, 5-HT_1A).

The NbN approach has been endorsed by expert groups that include the American, European and Asian Colleges of Neuropsychopharmacology.

Along with the revised nomenclature, the new system provides for each agent a list of indications approved by regulatory bodies such as the FDA and EMA, information on prevalent or life-threatening side effects, and evidence of additional efficacy (outside formal indications) filtered by the NbN Task Force and supported, for example, by expert guidelines.

There are also practical notes, and a brief discussion of relevant neurobiology.

For more information and to download the app, please see www.nbn2.com