Diclofenac (Diclofenac sodium) – Patient Information

Diclofenac is a well-known anti-inflammatory medicine used to relieve pain and reduce inflammation in conditions affecting muscles, joints, and soft tissues. In Australia, diclofenac is available in different forms (for example, tablets, enteric-coated tablets, gels/creams, and other presentations depending on the brand).

This guide is designed to be patient-friendly and to help you understand how diclofenac works, when it’s typically used, how to take it safely, and what to watch for. Always follow the directions on your specific product label and any advice from a healthcare professional.

Key Product Details

• Generic name: Diclofenac (diclofenac sodium)
• Medicinal class: Non-steroidal anti-inflammatory drug (NSAID)
• Common uses: Pain relief and inflammation reduction for musculoskeletal conditions
• Forms (varies by brand): Oral tablets/capsules, gels/creams, and other local preparations
• Common effects: Reduced pain, swelling, stiffness

How Diclofenac Works (Mechanism of Action)

Diclofenac belongs to the NSAID family. It works by reducing the production of certain chemicals in the body called prostaglandins. Prostaglandins are involved in pain signals and inflammation.

Diclofenac works mainly by inhibiting cyclo-oxygenase (COX) enzymes (COX-1 and COX-2). This lowers prostaglandin levels, which can lead to:

• Analgesia: less pain
• Anti-inflammatory action: reduced inflammation and swelling
• Antipyretic effect (sometimes): reduced fever, though this is not the primary use

Pharmacokinetics (Absorption, Distribution, Metabolism, Elimination)

Understanding how diclofenac moves through the body can help you take it correctly and recognise potential side effects. The exact profile can vary by formulation (oral vs topical) and by the specific brand.

Absorption

Oral diclofenac is absorbed through the gastrointestinal tract. Enteric-coated or delayed-release products are designed to reduce stomach irritation by modifying where and when the drug is released. Topical diclofenac (gels/creams) delivers medicine through the skin to local tissues; systemic absorption is usually lower than oral forms.

Distribution

Diclofenac distributes throughout the body. For joint-related pain, it can concentrate in inflamed tissues and synovial (joint) fluid where relevant.

Metabolism

Diclofenac is processed primarily by the liver via enzyme systems (including CYP pathways). This is one reason liver health is important when using NSAIDs.

Elimination

Diclofenac and its metabolites are eliminated mainly via the kidneys (through urine) and partially through bile and faeces. Kidney function can therefore be relevant for safety.

Typical Indications (When Diclofenac is Used)

Diclofenac is used for conditions where pain and inflammation are present. Common indications include:

• Osteoarthritis (joint pain and stiffness)
• Rheumatoid arthritis (inflammatory joint disease)
• Musculoskeletal pain such as strains, sprains, back pain, and soft tissue injuries
• Localised inflammatory conditions that may respond to topical diclofenac (for example, tendon or joint-region discomfort)
• Pain after injury or overuse (where inflammation contributes to symptoms)

Your best choice of formulation depends on the location of pain, severity, and your personal risk factors (for example, history of stomach ulcers, kidney disease, heart disease, or asthma triggered by NSAIDs).

Timing: When to Take Diclofenac

Timing depends on the product type and your dosing schedule. In general:

• Oral forms: take as directed on the label. If the product can irritate the stomach, taking with food may help reduce discomfort.
• Topical forms: apply to clean, dry skin over the painful area as directed. Avoid broken skin.
• Consistency: if using regularly for a condition, take doses at similar times each day.

If you miss a dose, take it when you remember unless it’s close to the next dose—then skip the missed dose. Do not take extra to make up for a missed dose.

Dosing (General Guidance)

Dosing varies by formulation, strength, and the condition being treated. Always follow your product label and/or the instructions that come with your medicine. Below is general patient information.

Oral diclofenac (tablets/capsules)

• Common schedules may include multiple doses per day depending on the product type (for example, immediate-release vs enteric-coated vs modified release).
• Use the lowest effective dose for the shortest necessary duration.

Topical diclofenac (gel/cream)

• Typically applied several times daily to the affected area as directed by the specific product.
• Only apply a thin layer and rub gently unless the label instructs otherwise.
• Wash hands after application (unless your hands are the treated area).

If you are unsure which strength or schedule applies to your specific brand, check the packaging or ask a pharmacist.

Food Interactions

Food can influence how quickly diclofenac is absorbed—especially for oral products—and it may affect stomach comfort.

With or without food

• Taking with food may reduce stomach upset for many people.
• Avoid lying down immediately after taking a dose if you experience reflux or heartburn.

For topical diclofenac, food interactions are generally not a main concern because systemic absorption is typically lower. However, follow the instructions on your product and avoid applying to large areas or using under tight bandages unless directed.

Alcohol Interactions (Important)

Combining NSAIDs like diclofenac with alcohol can increase the risk of stomach irritation, bleeding, and may worsen side effects. Alcohol may also affect your liver.

• It’s generally recommended to limit or avoid alcohol while using diclofenac.
• If you drink alcohol regularly, speak to a pharmacist or doctor about your individual risk.

Medicine Interactions (What to Tell Your Pharmacist)

Diclofenac can interact with a range of medicines. Always provide a full list of your medicines (including over-the-counter products and supplements). Key interaction categories include:

Other NSAIDs and pain relievers

• Avoid using two NSAIDs together (for example, diclofenac with ibuprofen or naproxen), unless a clinician specifically advises it.
• This can raise the risk of stomach and kidney complications.

Blood thinning medicines

• Diclofenac may increase bleeding risk when combined with anticoagulants (such as warfarin) or antiplatelet medicines (such as clopidogrel).
• Careful monitoring may be needed.

Blood pressure medicines and kidney risk

• Combining NSAIDs with some medicines used for blood pressure (for example, ACE inhibitors, angiotensin receptor blockers, or diuretics) can affect kidney function in some people.
• Dehydration (for example, during illness) increases risk further.

Corticosteroids

• Using diclofenac with corticosteroids can increase the risk of gastrointestinal ulceration or bleeding.

Selective serotonin reuptake inhibitors (SSRIs) and other antidepressants

• Some antidepressants (especially SSRIs) may increase bleeding risk when used with NSAIDs.

Lithium and methotrexate

• NSAIDs can influence levels of certain medicines like lithium and methotrexate, potentially increasing side effects.
• Appropriate timing and monitoring may be required.

Diuretics (water tablets)

• Diclofenac may reduce the effect of diuretics in some people.

This is not an exhaustive list. If you want, you can share the names of your medicines and we can help you identify potential interaction concerns to discuss with your pharmacist.

Safety Profile: Who Should Be Extra Cautious?

Like all NSAIDs, diclofenac can cause side effects. Most people tolerate it well when used correctly, but risks are higher in certain situations.

Common side effects

• Stomach discomfort, indigestion, nausea
• Headache, dizziness
• For topical products: local skin irritation, redness, itching, or rash

Serious risks (seek urgent medical help)

Stop using diclofenac and seek urgent help if you notice signs of:

• Gastrointestinal bleeding or ulcers: black/tarry stools, vomiting blood or material that looks like coffee grounds, severe stomach pain
• Allergic reactions: swelling of face/lips, wheezing, severe rash or blistering skin
• Cardiovascular events: chest pain, sudden shortness of breath, weakness on one side, trouble speaking
• Kidney problems: reduced urination, swelling of legs/feet, unusual fatigue
• Severe liver issues: yellowing of eyes/skin (jaundice), dark urine, severe upper abdominal pain

People at higher risk

• History of stomach ulcers or gastrointestinal bleeding
• Older age
• History of heart disease or stroke
• Kidney impairment or dehydration
• Asthma triggered by NSAIDs
• Concurrent use of other medicines that raise bleeding risk (for example, blood thinners, corticosteroids, SSRIs)
• Long-term or high-dose NSAID use

Practical Use Tips (How to Use Diclofenac Safely)

• Use the lowest effective dose for the shortest time needed to control symptoms.
• Follow the product instructions exactly—do not increase dose to “test” effectiveness.
• Take oral diclofenac with food if you get stomach upset.
• Avoid combining NSAIDs (for example, diclofenac + ibuprofen) unless advised by a clinician.
• For topical diclofenac: apply only to the affected area, avoid eyes and mucous membranes, and don’t apply under airtight dressings unless directed.
• Wash hands after applying gel/cream.
• Keep away from heat and sunlight on treated skin if your product label advises it.
• Stay hydrated, especially if you’re unwell, elderly, or using diuretics.
• If symptoms don’t improve after a short period, or pain worsens, seek professional advice.

Alternative Options

Depending on your condition and risk factors, alternatives may be considered. Common options include:

If you’d like, tell us what you’re treating (for example, knee osteoarthritis vs a sports injury) and any medical history (ulcers, kidney issues, heart conditions), and we can outline which alternatives might be worth discussing with a healthcare professional.

Market and Legal Context for Australia

In Australia, medicines containing diclofenac are regulated under the Therapeutic Goods Administration (TGA) framework. Availability can differ by product type (for example, oral vs topical), strength, and intended use.

Products may be supplied through community pharmacies, and some may be available without special requirements depending on their scheduling. Scheduling can change over time as evidence and regulatory guidance evolve.

Recent Guidance and Ongoing Safety Considerations

For NSAIDs, including diclofenac, regulatory and clinical guidance commonly emphasises:

• Using the lowest effective dose for the shortest duration
• Assessing cardiovascular and gastrointestinal risk before starting
• Reviewing ongoing need if used beyond short-term relief
• Considering stomach protection strategies in higher-risk individuals (as advised by a clinician)
• Avoiding NSAIDs in certain high-risk groups or using only with medical advice

If you are currently using diclofenac regularly, consider periodic medication reviews—especially if you have other health conditions or take multiple medicines.

Delivery and Availability

Diclofenac products may be available in different strengths and forms depending on brand and supply arrangements in Australia. Online pharmacies typically offer:

• Various diclofenac formulations (for example, oral tablets and topical gels/creams)
• Brand and strength options depending on stock
• Packaging suited to dispensing and consumer use

Delivery times can vary by location and courier. When ordering, check:

• Estimated dispatch and delivery timeframes shown at checkout
• Product availability and whether substitutions are allowed
• Storage instructions (for most diclofenac products, room temperature storage is typical unless stated otherwise)

Frequently Asked Questions (FAQ)

1) Is diclofenac the same as diclofenac sodium?

Diclofenac sodium is the salt form of diclofenac used in many products. The active component is diclofenac. You’ll see the names used interchangeably depending on the product label.

2) What is diclofenac used for?

Diclofenac is used to relieve pain and inflammation associated with conditions such as osteoarthritis, rheumatoid arthritis, and various musculoskeletal injuries or flare-ups. Topical forms are commonly used for localised aches and joint-region discomfort.

3) How long does diclofenac take to work?

Many people notice pain relief within hours after an oral dose, while topical products may take some time to reach full effect. Improvement should occur over the first day or so for acute injuries, but persistent or worsening symptoms should be assessed.

4) Can I take diclofenac with food?

Yes, taking oral diclofenac with food may help reduce stomach upset. Follow your specific product instructions for best results.

5) Can I drink alcohol while using diclofenac?

It’s generally recommended to limit or avoid alcohol while taking diclofenac because alcohol can increase the risk of stomach irritation and bleeding. If you drink regularly, discuss your situation with a pharmacist.

6) What should I avoid when using diclofenac?

Avoid combining diclofenac with other NSAIDs (such as ibuprofen or naproxen) unless directed. Also be cautious with blood thinners, corticosteroids, and certain antidepressants due to bleeding risk.

7) Are topical diclofenac gels safer than tablets?

Topical products typically result in lower systemic absorption than oral NSAIDs, which may reduce some risks. However, topical diclofenac can still cause side effects—especially if used incorrectly or over large areas. Always follow label directions.

8) Can diclofenac be used for back pain or sprains?

Diclofenac can be used for musculoskeletal pain, including back pain and sprains/strains, when appropriate. If pain is severe, associated with numbness, or lasts longer than expected, seek medical advice.

9) What are warning signs that I should stop and get help?

Seek urgent help if you experience symptoms of stomach bleeding (black stools, vomiting blood), severe allergic reactions (swelling, breathing difficulty), chest pain, sudden shortness of breath, signs of liver trouble (jaundice), or signs of kidney problems (reduced urination, marked swelling).

10) What if diclofenac doesn’t help?

If your symptoms are not improving after a short period, or they worsen, stop and consider further assessment. Ongoing pain may require a different diagnosis or treatment plan.

Important Reminder

This information is general. Your suitable dose and formulation depend on your health history, the nature of your symptoms, and other medicines you take. If you have questions about diclofenac or want help choosing the right option, speak with a pharmacist.