chemistry

Diclofenac

Diclofenac 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 Diclofenac rather than just read about it. In short: Diclofenac, sold under the brand name Voltaren among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammatory diseases such as gout. It can be taken orally (swallowed by mouth), inserted rectally as a suppository, injected intramuscularly, injected intravenously, applied to the skin topically, or through eye drops.

Key takeaways

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

Reference excerpt

Diclofenac, sold under the brand name Voltaren among others, is a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain and inflammatory diseases such as gout. It can be taken orally (swallowed by mouth), inserted rectally as a suppository, injected intramuscularly, injected intravenously, applied to the skin topically, or through eye drops. Improvements in pain last up to eight hours. It is also available as the fixed-dose combination diclofenac/misoprostol (Arthrotec) to help protect the stomach; however, proton pump inhibitors such as omeprazole are typically first-line since they are at least as effective as misoprostol, but with better tolerability. Common side effects include abdominal pain, gastrointestinal bleeding, nausea, dizziness, headache, and swelling. Serious side effects may include heart disease, stroke, kidney problems, and stomach ulceration. Use is not recommended in the third trimester of pregnancy. It is likely safe during breastfeeding. Diclofenac is believed to work by decreasing the production of prostaglandins, like other drugs in this class. In 2023, it was the 73rd most commonly prescribed medication in the United States, with more than 9 million prescriptions. It is available as its acid or in two salts, as either diclofenac sodium or potassium.

Medical uses Diclofenac is used to treat pain related to arthritis, dysmenorrhea, rheumatic diseases and other inflammatory disorders, kidney stones and gallstones. An additional indication is the treatment of acute migraines. Diclofenac is used to treat mild to moderate postoperative or post-traumatic pain, in particular when inflammation is also present. Diclofenac ophthalmic is indicated for the treatment of postoperative inflammation in people who have undergone cataract extraction and for the temporary relief of pain and photophobia in people undergoing corneal refractive surgery. Diclofenac may also help with actinic keratosis and with acute pain caused by minor strains, sprains and contusions. In many countries, eye drops are sold to treat acute and chronic nonbacterial inflammation of the anterior part of the eyes (such as postoperative states). The eye drops have also been used to manage pain for traumatic corneal abrasion. Diclofenac is often used to treat chronic pain associated with cancer, especially if inflammation is present.

Contraindications Diclofenac is contraindicated for pregnant women; for people with active stomach or duodenal ulceration or gastrointestinal bleeding; and for people undergoing coronary artery bypass surgery.

Adverse effects

Diclofenac consumption has been associated with significantly increased vascular and coronary risk in a study including COX-2 inhibitors, diclofenac, ibuprofen and naproxen. Upper gastrointestinal complications were also reported. Major adverse cardiovascular events were increased by about a third by diclofenac, chiefly due to an increase in major coronary events. Compared with placebo, of 1000 patients allocated to diclofenac for a year, three more had major vascular events, one of which was fatal. Vascular death is increased significantly by diclofenac. In October 2020, the US Food and Drug Administration (FDA) required the prescribing information to be updated for all nonsteroidal anti-inflammatory medications to describe the risk of kidney problems in fetuses that result in low amniotic fluid.

Heart In 2013, a study found major vascular events were increased by about a third by diclofenac, chiefly due to an increase in major coronary events. Compared with placebo, of 1000 people allocated to diclofenac for a year, three more had major vascular events, one of which was fatal. Vascular death was increased by diclofenac (1·65). Following the identification of increased risks of heart attacks with the selective COX-2 inhibitor rofecoxib in 2004, attention has focused on all the other members of the nonsteroidal anti-inflammatory drug group, including diclofenac. Research results are mixed, with a meta-analysis of papers and reports up to April 2006 suggesting a relative increased rate of heart disease of 1.63 compared to nonusers. Professor Peter Weissberg, medical director of the British Heart Foundation said, "However, the increased risk is small, and many patients with chronic debilitating pain may well feel that this small risk is worth taking to relieve their symptoms". Only aspirin was found not to increase the risk of heart disease; however, this is known to have a higher rate of gastric ulceration than diclofenac. As of January 2015, the MHRA announced that diclofenac would be reclassified as a prescription-only medicine (POM) due to the risk of cardiovascular adverse events. A 2006 large observational study of 74,838 US users of nonsteroidal anti-inflammatory drugs or coxibs found no additional cardiovascular risk from diclofenac use. A very large study of 1,028,437 Danish users of various nonsteroidal anti-inflammatory drugs or coxibs found the "Use of the nonselective NSAID diclofenac and the selective cyclooxygenase-2 inhibitor rofecoxib was associated with an increased risk of cardiovascular death (odds ratio, 1.91; 95% confidence interval, 1.62 to 2.42; and odds ratio, 1.66; 95% confidence interval, 1.06 to 2.59, respectively), with a dose-dependent increase in risk." Diclofenac is similar in COX-2 selectivity to celecoxib.

Gastrointestinal

Gastrointestinal complaints are most often noted. Most patients receive a gastro-protective drug as prophylaxis during long-term treatment (misoprostol, ranitidine, or omeprazole).

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Diclofenac

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

In research: Diclofenac 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 Diclofenac 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: Diclofenac is common in secondary-school and first-year university syllabi. It links to neighbouring topics Acetic acids, Anilines, Dermatoxins, so understanding it makes those chapters shorter.
In everyday life: Look for Diclofenac 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 Diclofenac in 20 minutes

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

Frequently asked questions

What is Diclofenac in simple terms?

Why does Diclofenac 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 Diclofenac?

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 Diclofenac.