chemistry

PF-04455242

PF-04455242 is a chemistry 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 PF-04455242 rather than just read about it. In short: PF-04455242 is an experimental κ-opioid receptor (KOR) antagonist which was under development by Pfizer for the treatment of bipolar depression but was never marketed. Its development was discontinued in early clinical trials.

Key takeaways

PF-04455242 belongs to chemistry; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect PF-04455242 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of PF-04455242 from memory before moving on to harder problems.

Reference excerpt

PF-04455242 is an experimental κ-opioid receptor (KOR) antagonist which was under development by Pfizer for the treatment of bipolar depression but was never marketed. Its development was discontinued in early clinical trials. It is taken by mouth.

Pharmacology The drug is a selective KOR antagonist and shows approximately 10- to 20-fold higher affinity for the KOR (Ki = 1–3 nM) over the μ-opioid receptor (MOR) (Ki = 10–64 nM) and has negligible affinity for the δ-opioid receptor (DOR) (Ki > 4,000 nM). It is a "short-acting" or non-inactivating antagonist of the KOR (as opposed to irreversible antagonists like JDTic). Although originally characterized as a KOR neutral antagonist however, subsequent research revealed in 2020 that PF-04455242 is actually only a moderately efficacious partial antagonist of the KOR (Imax ≈ 50%). In any case, the drug reversed the analgesic and prolactin-elevating effects of the KOR agonist spiradoline in animals, showed efficacy in animal models predictive of antidepressant activity, and reversed stress-induced reinstatement of cocaine-seeking behavior. However, PF-04455242 also showed a variety of other weak off-target activities.

Clinical studies PF-04455242 reached phase 1 clinical trials for bipolar depression prior to the discontinuation of its development in 2010. Its development was discontinued upon unfavorable toxicological findings in animals that had been exposed to the drug for 3 months. Along with JDTic, which was also discontinued due to toxicity findings early in clinical trials, PF-04455242 was one of the first KOR antagonists to be developed for potential treatment of psychiatric disorders. It was in phase 1 trials by 2009 and was first described in the scientific literature by 2010.

See also κ-Opioid receptor § Antagonists List of investigational antidepressants List of investigational bipolar disorder drugs

References

External links PF-4455242 (PF-04455242) - AdisInsight

Illustrations

Worked examples

Example 1 — a first encounter with PF-04455242

Start with the simplest possible case. Write down what PF-04455242 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In chemistry, 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 PF-04455242 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 PF-04455242 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 PF-04455242

In research: PF-04455242 appears in chemistry 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 PF-04455242 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: PF-04455242 is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1-Pyrrolidinyl compounds, Abandoned drugs, Drugs developed by Pfizer, so understanding it makes those chapters shorter.
In everyday life: Look for PF-04455242 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 PF-04455242 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what PF-04455242 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 PF-04455242 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is PF-04455242 in simple terms?

Why does PF-04455242 matter?

Because it connects several chemistry 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 PF-04455242?

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 PF-04455242.