Nedaplatin

Key takeaways

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

Reference excerpt

Nedaplatin, sold in Japan as Aqupla (see External Links), is a platinum-based chemotherapy agent. It is toxic to DNA, causing damage to DNA, limiting DNA repair and ultimately limiting DNA synthesis, limiting the propagation of cancer cells.

Medical uses Nedaplatin can be prescribed to patients with the following types of cancer:

small/non-small cell lung cancer oesophageal cancer uterine cervical cancer urothelial cancer testicular cancer ovarian cancer prostate cancer head and neck cancer Nedaplatin is most often compared to other platinum-based drugs, most notably cisplatin. Many randomized controlled trials have been performed to compare nedaplatin and cisplatin, with uncertain results. One meta-analysis of 14 trials indicated no difference in efficacy in terms of median overall survival. Another meta-analysis of 17 trials looking specifically at concurrent chemoradiotherapy treatment for cervical cancer also found no difference in 3 year all-cause mortality, but did favour nedaplatin for 1 year all-cause mortality.

Available forms Nedaplatin comes as a powder, since it is unstable in a solution. For clinical administration, it is dissolved in a liquid and administered intravenously.

Adverse effects Nephrotoxicity: Like cisplatin, nephrotoxicity, harm to the kidneys, is the primary dose-limiting factor. However, the nephrotoxicity of nedaplatin has been shown to be less severe than cisplatin. In rats, nedaplatin primarily affected the renal papilla, with papillary necrosis in severe cases. Neurotoxicity: Nedaplatin is widely reported to be neurotoxic, especially to the nerves of the ear. Causing symptoms like numbness and tingling in mild cases, or sensory ataxia in more severe cases. Nausea and vomiting: The emetogenic effects of nedaplatin are commonly managed with prophylactic antiemetics, such as duplex dexamethasone and ondansetron or triplex dexamethasone, ondansetron and aprepitant. Ototoxicity: Nedaplatin is toxic to the nerve and hair cells in the cochlea. In rats, nedaplatin was severely toxic to the nerve cells at a concentration of 10 μM, with damage to hair cells becoming more severe exceeding 100 μM. Neutropenia, leukopenia, anemia and thrombocytopenia (see "Aqupla アクプラ" in External Links): Nedaplatin is toxic to the hemopoietic cells of the bone marrow, combined with reduced levels of erythropoietin, leads to elevated incidence of bone marrow suppression compared to cisplatin. Incidence of severe grades of leukopenia and neutropenia are reported to be higher than cisplatin in treatment combined with radiotherapy. These haematological adverse effects are common in general.

Toxicity The recommended therapeutic dose is 80-100 mg/m2 body area. Optimal dosage is determined based on measurements of unbound platinum concentration following intravenous infusion, combined with rate of creatine clearance as an assessment of renal function using Ishibashi’s formula: DoseNDP = AUC × CLNDP, where CLNDP = 0.0738 × creatinine clearance + 4.47 The exact mechanism of uptake into the cell is unknown, with information being considerably less available compared to cisplatin. What is known is that nedaplatin does not interact with the Oct2 or apical multidrug and toxin extrusion transporter (MATE) transporters, potentially explaining the difference in nephrotoxicity due to reduced accumulation in the proximal tubules of the kidney. Toxicogenomics has helped elucidate some of the mechanisms behind nephrotoxicity, where oxidative stress has been shown to deregulate gene expression via Hmox1 and other genes.

Pharmacology

Mechanism of action Disruption of the DNA structure caused by the crosslinksobstructs the DNA polymerases, preventing DNA replication and transcription. This causes the cell to go into cell cycle arrest it cannot go on from the G2 to the M phase and stops at the G2/M checkpoint. The cell tries to repair the DNA before dividing. The intrastrand crosslinks are normally repaired by the excision repair pathway. It attempts to remove the platinum adducts. If repair fails or is insufficient, apoptosis is induced and leads to cell death. However, cancer cells have impaired apoptosis pathways limited DNA repair pathways. This can decrease the efficacy of the drug and can lead to resistance to the drug. It has been observed that radiotherapy pairs well with administration with the drug, but how this works is not entirely established. It is known that cells that cells that are stuck at the G2/M phase of the cell cycle and have impaired DNA repair system are more sensitive to radiotherapy. This suggests that nedaplatin is a radiosensitizer,

Pharmacokinetics Nedaplatin is administered in its active form and is removed from the bloodstream by the kidneys to leave the body via the urine. The recommended therapeutic dose of nedaplatin is 80–100 mg/m2 of body surface area. Optimal dosing is determined using measurements of unbound platinum concentrations following intravenous infusion together with an assessment of renal function using creatinine clearance. The dose can be estimated using Ishibashi’s formula: DoseNDP = AUC × CLNDP, where CLNDP = 0.0738 × creatinine clearance + 4.47 The precise mechanism of cellular uptake is not fully understood, and substantially less information is available compared with cisplatin. However, nedaplatin does not interact with the Oct2 transporter or apical multidrug and toxin extrusion (MATE) transporters, which may contribute to its lower accumulation in renal proximal tubules.

Chemistry

Structure Like most Platinum-based anti cancer drugs, nedaplatin is a square planar platinum(II) complex. It contains two leaving groups in the form of the glycolate and two mutually cis amines.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Nedaplatin

Start with the simplest possible case. Write down what Nedaplatin 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 Nedaplatin 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 Nedaplatin 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 Nedaplatin

In research: Nedaplatin 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 Nedaplatin 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: Nedaplatin is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ammine complexes, Drugs not assigned an ATC code, Platinum(II) compounds, so understanding it makes those chapters shorter.
In everyday life: Look for Nedaplatin 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.

How to study Nedaplatin in 20 minutes

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

Frequently asked questions

What is Nedaplatin in simple terms?

Nedaplatin, sold in Japan as Aqupla (see External Links), is a platinum-based chemotherapy agent. It is toxic to DNA, causing damage to DNA, limiting DNA repair and ultimately limiting DNA synthesis, limiting the propagation of cancer cells.

Why does Nedaplatin 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 Nedaplatin?

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 Nedaplatin.