science

ITI-1549

ITI-1549 is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand ITI-1549 rather than just read about it. In short: ITI-1549 is a putatively non-hallucinogenic serotonin 5-HT2A receptor agonist of the pyridopyrroloquinoxaline family which is under development for the treatment of mood disorders and other psychiatric disorders. In addition to acting at the serotonin 5-HT2A receptor, it is also an antagonist of the serotonin 5-HT2B receptor and an agonist of the serotonin 5-HT2C receptor.

Key takeaways

ITI-1549 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect ITI-1549 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of ITI-1549 from memory before moving on to harder problems.

Reference excerpt

ITI-1549 is a putatively non-hallucinogenic serotonin 5-HT2A receptor agonist of the pyridopyrroloquinoxaline family which is under development for the treatment of mood disorders and other psychiatric disorders. In addition to acting at the serotonin 5-HT2A receptor, it is also an antagonist of the serotonin 5-HT2B receptor and an agonist of the serotonin 5-HT2C receptor. The drug's route of administration has not been specified.

Interactions

Pharmacology

Pharmacodynamics Serotonergic psychedelics like psilocybin and lysergic acid diethylamide (LSD) are agonists of the serotonin 5-HT2A receptor that activate both the β-arrestin and Gq signaling pathways. In 2023, activation of the Gq pathway, but not the β-arrestin pathway, was linked with the production of hallucinogenic-like effects, specifically the head-twitch response (HTR), in animals. Serotonin 5-HT2A receptor agonists are of interest for the potential treatment of psychiatric disorders like depression and anxiety, but the hallucinogenic effects of serotonergic psychedelics serve as a barrier and partial limiting factor in this regard. ITI-1549 has high affinity for the serotonin 5-HT2A receptor (Ki = 10.2 nM) and acts as a partial agonist of the β-arrestin pathway with an intrinsic activity of 72% (relative to α-methylserotonin). Conversely, unlike serotonergic psychedelics, ITI-1549 does not activate the Gq pathway. Hence, it is a biased agonist of the serotonin 5-HT2A receptor. In accordance with the preceding, ITI-1549 does not produce the HTR, a behavioral proxy of psychedelic effects, in animals. However, similarly to serotonergic psychedelics, ITI-1549 has been found to produce anxiolytic-like and prosocial effects in animals. Antidepressant-like and psychoplastogenic effects of ITI-1549 in animals have yet to be assessed or reported. In any case, various other non-hallucinogenic serotonin 5-HT2A receptor agonists selective for the β-arrestin pathway have been found to produce antidepressant-like effects in animals. In addition to the serotonin 5-HT2A receptor, ITI-1549 has high affinity for the serotonin 5-HT2B receptor (Ki = 4.8 nM). However, it acts as an antagonist of this receptor rather than as an agonist (IC50Tooltip half-maximal inhibitory concentration = 13.8 nM). Based on these findings, continuous administration of ITI-1549 is not expected to pose a risk of cardiac valvulopathy. This is in contrast to many serotonergic psychedelics, which have been shown to act as potent serotonin 5-HT2B receptor agonists. ITI-1549 is additionally a potent agonist of the serotonin 5-HT2C receptor (Ki = 21 nM; EC50Tooltip half-maximal effective concentration = 40 nM).

Chemistry The chemical structure was disclosed in a 2024 patent. It is a pyridopyrroloquinoxaline derivative and is structurally related to the atypical antipsychotic lumateperone.

History ITI-1549 was first described in the scientific literature by 2023.

Research As of February 2024, ITI-1549 is in the preclinical research stage of development for treatment of psychiatric disorders. A phase 1 clinical trial is being planned and is expected to commence in late 2024 or early 2025. The drug is under development by Intra-Cellular Therapies.

See also Pyridopyrroloquinoxaline List of investigational hallucinogens and entactogens List of miscellaneous 5-HT2A receptor agonists Non-hallucinogenic 5-HT2A receptor agonist

References

External links ITI-1549 - Isomer Design

Illustrations

Worked examples

Example 1 — a first encounter with ITI-1549

Start with the simplest possible case. Write down what ITI-1549 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to ITI-1549 before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about ITI-1549 ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of ITI-1549

In research: ITI-1549 appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses ITI-1549 in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: ITI-1549 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 5-HT2A agonists, 5-HT2B antagonists, 5-HT2C agonists, so understanding it makes those chapters shorter.
In everyday life: Look for ITI-1549 outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study ITI-1549 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what ITI-1549 means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain ITI-1549 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is ITI-1549 in simple terms?

Why does ITI-1549 matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study ITI-1549?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on ITI-1549.