Diclofenac: Uses, Dosage & Side Effects
A potent non-steroidal anti-inflammatory drug (NSAID) available as topical gel, enteric-coated tablets, and eye drops for the relief of pain, inflammation, and swelling
Diclofenac is one of the most widely used non-steroidal anti-inflammatory drugs (NSAIDs) worldwide. It provides effective relief from pain, inflammation, and swelling associated with musculoskeletal conditions, including sprains, strains, sports injuries, and arthritis. Available as a topical gel for localized treatment, enteric-coated tablets for systemic use, and eye drops for ophthalmic conditions, diclofenac is listed on the WHO Model List of Essential Medicines. The topical gel formulation is available over the counter in most countries, offering targeted pain relief with significantly lower systemic side effects compared to oral NSAIDs.
Quick Facts: Diclofenac
Key Takeaways
- Diclofenac is a potent NSAID used to treat pain, inflammation, and swelling from musculoskeletal injuries and arthritis, available as a topical gel (OTC), enteric-coated tablets, and eye drops.
- The topical gel formulation delivers diclofenac directly to the affected area with minimal systemic absorption (less than 6%), resulting in significantly fewer gastrointestinal and cardiovascular side effects compared to oral tablets.
- Oral diclofenac carries an increased risk of cardiovascular events (heart attack, stroke), gastrointestinal bleeding, and kidney damage, especially with prolonged use or in patients with pre-existing conditions.
- Do not use diclofenac in the last three months of pregnancy. The gel should not be applied to broken skin, open wounds, or mucous membranes, and sun exposure on treated areas should be avoided.
- Diclofenac should not be combined with other NSAIDs (such as ibuprofen or aspirin for pain) but can be used alongside paracetamol for enhanced pain relief through complementary mechanisms.
What Is Diclofenac and What Is It Used For?
Diclofenac belongs to the phenylacetic acid class of non-steroidal anti-inflammatory drugs (NSAIDs) and is one of the most extensively studied and widely prescribed medications in this category. First developed in the 1960s and introduced for clinical use in the 1970s, diclofenac has become a cornerstone in the management of pain and inflammatory conditions. It is included on the World Health Organization (WHO) Model List of Essential Medicines, reflecting its importance in global healthcare.
The medication works by inhibiting both cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes, which are responsible for the synthesis of prostaglandins. Prostaglandins play a central role in the inflammatory response, causing pain, swelling, redness, and heat at sites of tissue injury. By reducing prostaglandin production, diclofenac delivers potent analgesic (pain-relieving), anti-inflammatory (swelling-reducing), and antipyretic (fever-reducing) effects. Compared to many other NSAIDs, diclofenac shows somewhat greater selectivity for COX-2, which contributes to its strong anti-inflammatory activity.
Diclofenac is available in several formulations to suit different clinical needs. The topical gel (typically containing diclofenac diethylamine equivalent to 1% diclofenac sodium, or 11.6 mg/g) is designed for application directly to the skin over the affected area. This route provides localized pain relief for soft tissue injuries such as sprains, strains, bruises, and sports injuries, while minimizing the amount of drug entering the general circulation. Studies show that only approximately 6% of the topically applied dose is absorbed systemically, which significantly reduces the risk of the gastrointestinal, cardiovascular, and renal side effects associated with oral NSAIDs.
The enteric-coated tablet formulation (typically 25 mg or 50 mg) provides systemic anti-inflammatory and analgesic effects for conditions requiring broader treatment, including osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute gout, and post-operative or post-traumatic pain. The enteric coating protects the stomach lining by ensuring the tablet does not dissolve until it reaches the small intestine, though this does not eliminate the systemic risk of gastrointestinal complications.
Eye drops (diclofenac sodium 1 mg/ml, or 0.1%) are used in ophthalmology to manage postoperative ocular inflammation and pain following cataract surgery, as well as for the prevention and treatment of cystoid macular edema. They may also be used to manage pain associated with corneal abrasions or photorefractive surgery. Ophthalmic diclofenac provides targeted anti-inflammatory effects within the eye with minimal systemic exposure.
For the topical gel formulation, which is the most commonly used OTC form, the primary indications include mild to moderate pain associated with muscle and joint injuries such as sports injuries, sprains, and strains in adults and adolescents over 14 years of age. The gel is designed for short-term use (up to 7 days without medical supervision) and provides effective local anti-inflammatory and analgesic activity by penetrating through the skin to reach the underlying muscles, joints, and synovial fluid.
What Should You Know Before Using Diclofenac?
Contraindications
There are specific situations where diclofenac must not be used. Understanding these absolute contraindications is critical for safe medication use. You should not use diclofenac (in any formulation) if you:
- Are allergic to diclofenac or any of the inactive ingredients in the specific product (see the product packaging for a complete list of excipients).
- Have experienced asthma, bronchospasm, hives (urticaria), nasal polyps, or angioedema after taking aspirin or other NSAIDs (such as ibuprofen). This is known as NSAID-exacerbated respiratory disease (N-ERD), previously called the aspirin triad or Samter's triad, and use of any NSAID can trigger a potentially severe or life-threatening reaction.
- Are in the last three months (third trimester) of pregnancy, as diclofenac can cause premature closure of the ductus arteriosus in the fetus, prolonged labor, and other complications during delivery.
- Are under 14 years of age (for the topical gel formulation). Efficacy and safety data in children under 14 are limited for this formulation.
For the topical gel specifically, do not apply to:
- Open wounds, cuts, or broken skin
- Infected or inflamed skin
- Eczema or dermatitis
- Mucous membranes (inside the mouth, nose, genitals)
- Eyes or the area around the eyes (use the ophthalmic formulation for eye conditions)
Warnings and Precautions
All NSAIDs, including diclofenac, may increase the risk of cardiovascular thrombotic events (heart attack, stroke), gastrointestinal bleeding and ulceration, and impaired kidney function. These risks are generally dose-dependent and increase with duration of use. Topical diclofenac gel carries substantially lower systemic risk than oral formulations.
You should consult your doctor or pharmacist before using diclofenac if you have any of the following conditions or risk factors:
- Asthma or history of allergic respiratory disease: Patients with asthma, hay fever (seasonal allergic rhinitis), nasal polyps, chronic obstructive pulmonary disease (COPD), or chronic respiratory infections have an increased risk of NSAID-triggered bronchospasm and should use diclofenac only under medical supervision with appropriate emergency preparedness.
- History of allergic reactions to other substances: If you have a history of allergic skin reactions, itching, or hives to various triggers, you may be at increased risk of hypersensitivity reactions to diclofenac.
- Impaired kidney function: Diclofenac can affect kidney function by reducing renal blood flow. Patients with kidney disease should use diclofenac with caution and under medical guidance.
- Impaired liver function: The liver metabolizes diclofenac, and impaired hepatic function may increase drug levels and the risk of adverse effects.
- Heart disease or heart failure: NSAIDs can cause fluid retention and worsen heart failure. Patients with cardiovascular disease should discuss NSAID use with their doctor.
- Active peptic ulcer disease: Oral diclofenac can worsen existing ulcers and cause gastrointestinal bleeding. Even topical use over large areas for extended periods may carry some systemic risk.
When using the topical gel, additional precautions apply. If the gel is applied to large skin areas for extended periods, the risk of systemic side effects cannot be entirely excluded. After application, allow the gel to dry for several minutes before covering with a breathable (non-occlusive) bandage. Do not use airtight or occlusive dressings over the treated area. Discontinue use if a skin rash develops. Avoid direct sunlight and artificial UV light (tanning beds) on the treated area during treatment and for at least two weeks after stopping, as photosensitivity reactions can occur. Wash hands after application unless the hands are the area being treated, and ensure children do not touch the treated skin.
When using diclofenac gel without medical advice, do not use for more than 7 days. If symptoms worsen or do not improve within this period, consult a doctor. For adolescents aged 14 and over, consult a doctor if the medication is needed for more than 7 days or if symptoms worsen.
Pregnancy and Breastfeeding
Diclofenac must not be used during the last three months (third trimester) of pregnancy, regardless of the formulation. During this period, all NSAIDs can cause premature closure of the ductus arteriosus in the fetus, impair fetal kidney function leading to reduced amniotic fluid (oligohydramnios), inhibit uterine contractions potentially prolonging labor, and increase the risk of bleeding in both mother and baby.
During the first six months of pregnancy, diclofenac (including the topical gel) should only be used when strictly necessary and on the advice of a doctor, at the lowest effective dose for the shortest possible duration. While oral formulations of diclofenac are known to carry risks for the developing fetus, it is not fully established whether the same level of risk applies to the topical gel given its lower systemic absorption. Nevertheless, a cautious approach is recommended.
Small amounts of diclofenac pass into breast milk. When using the gel while breastfeeding, do not apply it to the breasts, and avoid applying it over large skin areas or for prolonged periods. Diclofenac gel should only be used during breastfeeding on the advice of a healthcare professional.
Driving and Operating Machinery
Diclofenac topical gel has no known effect on the ability to drive or operate machinery, as systemic absorption is minimal. However, oral diclofenac may occasionally cause dizziness, drowsiness, visual disturbances, or fatigue, particularly at higher doses. If you experience any of these effects, do not drive or operate machinery until the symptoms have resolved.
How Does Diclofenac Interact with Other Drugs?
For diclofenac topical gel used as directed, no clinically significant drug interactions have been reported in clinical studies. The low systemic absorption of the topical formulation (approximately 6% of the applied dose) means that drug interactions typical of oral NSAIDs are unlikely at recommended doses. However, if the gel is applied to large skin areas for extended periods, the possibility of systemic interactions cannot be entirely excluded.
For oral diclofenac and for situations where systemic exposure may be relevant, the following interactions are important to be aware of. Always inform your doctor, pharmacist, or nurse about all medications, herbal remedies, and supplements you are taking.
Major Interactions
| Interacting Drug | Effect | Clinical Advice |
|---|---|---|
| Warfarin and other anticoagulants | NSAIDs increase the risk of gastrointestinal bleeding and may enhance the anticoagulant effect of warfarin, raising INR and bleeding risk | Avoid combination if possible. If necessary, monitor INR frequently and watch for signs of bleeding. Consult your doctor. |
| Other NSAIDs (ibuprofen, naproxen, aspirin) | Concurrent use of two or more NSAIDs significantly increases the risk of gastrointestinal ulceration, bleeding, and kidney damage without meaningful additional analgesic benefit | Never combine diclofenac with other NSAIDs. Choose one NSAID at a time. Low-dose aspirin for cardiovascular protection may be continued under medical supervision. |
| Lithium | Diclofenac can increase serum lithium levels by reducing renal lithium clearance, potentially leading to lithium toxicity | Monitor lithium blood levels closely when starting, stopping, or changing the dose of diclofenac. Adjust lithium dose as needed. |
| Methotrexate | NSAIDs reduce renal clearance of methotrexate, potentially raising methotrexate levels to toxic concentrations | Use with extreme caution. Avoid diclofenac within 24 hours before or after methotrexate dosing. Monitor blood counts and kidney function. |
| ACE inhibitors and ARBs | NSAIDs can reduce the blood pressure-lowering effect of ACE inhibitors and angiotensin receptor blockers, and the combination increases the risk of acute kidney injury, especially when combined with diuretics | Monitor blood pressure and kidney function. Stay well hydrated. The "triple whammy" combination (NSAID + ACE inhibitor/ARB + diuretic) should be avoided. |
Minor Interactions
| Interacting Drug | Effect | Clinical Advice |
|---|---|---|
| SSRIs (e.g., sertraline, fluoxetine) | SSRIs impair platelet function; combining with NSAIDs increases gastrointestinal bleeding risk | Consider gastroprotective therapy (e.g., a proton pump inhibitor) if concurrent use is necessary. |
| Corticosteroids (e.g., prednisolone) | Concurrent use increases the risk of gastrointestinal ulceration and bleeding | Use the lowest effective dose for the shortest time. Consider gastroprotection. |
| Diuretics (furosemide, thiazides) | NSAIDs can reduce the diuretic and antihypertensive effects of diuretics and increase the risk of acute kidney injury through reduced renal perfusion | Monitor kidney function and blood pressure. Ensure adequate hydration. |
| Digoxin | Diclofenac may increase serum digoxin levels by reducing renal clearance | Monitor digoxin levels when initiating or discontinuing concurrent NSAID use. |
| Cyclosporine | Both drugs can impair kidney function; combined use increases nephrotoxicity risk | Use with caution and monitor renal function closely. |
At the recommended doses for topical diclofenac gel (up to 16 g per day on a localized area), no clinically relevant drug interactions have been documented. The systemic exposure is significantly lower than with oral formulations. However, if you are using multiple topical products on the same area, consult your pharmacist to ensure compatibility.
What Is the Correct Dosage of Diclofenac?
Diclofenac dosing varies significantly depending on the formulation (gel, tablet, or eye drops), the condition being treated, and individual patient factors. The following guidelines apply to each formulation. Always use the lowest effective dose for the shortest duration necessary to control symptoms.
Topical Gel (11.6 mg/g or 1% Diclofenac)
Adults and Adolescents Over 14 Years
Single application: 1 to 4 grams (a cherry-sized to walnut-sized amount)
Frequency: 3 to 4 times daily
Maximum daily dose: 16 grams of gel per day
Application method: Apply a thin layer to the affected area and gently massage into the skin. Wash hands afterwards (unless the hands are the treated area). Allow the gel to dry for a few minutes before covering with clothing or a breathable bandage.
Duration: Maximum 7 days without medical advice. Consult a doctor if symptoms persist or worsen.
Enteric-Coated Tablets (25 mg, 50 mg)
Adults (Oral Dosing – Prescription)
Mild to moderate pain: 75–150 mg daily, divided into 2–3 doses
Osteoarthritis: 100–150 mg daily in divided doses
Rheumatoid arthritis: 150–200 mg daily in divided doses
Maximum daily dose: 150 mg for most indications (200 mg in severe rheumatoid arthritis under specialist supervision)
Note: Take with food or immediately after meals to reduce gastrointestinal irritation. Swallow tablets whole; do not crush or chew the enteric coating.
Eye Drops (1 mg/ml)
Adults (Ophthalmic – Prescription)
Post-cataract surgery: One drop into the affected eye 3–5 times daily, starting 24 hours before surgery and continuing for 2–4 weeks post-operatively
Post-corneal surgery: As directed by the ophthalmologist, typically one drop 4 times daily for the prescribed duration
Note: Do not wear contact lenses while using diclofenac eye drops. Use exactly as prescribed by your eye specialist.
Children and Adolescents
Diclofenac topical gel should not be used in children under 14 years of age, as safety and efficacy data in this age group are limited for the topical formulation. For adolescents aged 14 and over, the gel may be used at the same dosage as adults but should not be continued for more than 7 days without medical consultation. If symptoms worsen, parents or guardians should seek medical advice promptly.
Oral diclofenac may be used in children for specific conditions (such as juvenile idiopathic arthritis) at weight-based doses under specialist pediatric supervision, typically 1–3 mg/kg/day in divided doses. This should only be done under the direction of a physician experienced in pediatric rheumatology.
Elderly Patients
No specific dose adjustment is required for elderly patients using diclofenac gel. However, older adults should be particularly vigilant for side effects and should consult a doctor or pharmacist at the first sign of any adverse reaction. For oral diclofenac, the elderly are at higher risk of gastrointestinal complications, cardiovascular events, and renal impairment. The lowest effective dose should be used, and many guidelines recommend gastroprotective therapy (e.g., a proton pump inhibitor) when oral NSAIDs are prescribed to patients over 65 years of age.
Hepatic and Renal Impairment
No specific dose reduction is necessary for the topical gel in patients with mild to moderate liver or kidney impairment, given the low systemic absorption. However, the gel should be used with caution in these patients as systemic side effects cannot be entirely excluded with extensive or prolonged use. For oral diclofenac, patients with significant hepatic or renal impairment require dose reduction and careful monitoring by their healthcare provider.
Missed Dose
If you forget to apply the gel at the scheduled time, apply it as soon as you remember. If it is nearly time for the next application, skip the missed dose and continue with your regular schedule. Do not apply a double dose to compensate for a missed application.
Overdose
Oral diclofenac overdose is a medical emergency. If you or someone else has ingested an excessive amount of diclofenac tablets, contact emergency services or your local poison control center immediately, even if there are no symptoms yet.
Overdose with diclofenac topical gel is highly unlikely due to the low systemic absorption from skin application. Even if an excessive amount of gel is applied, the risk of serious systemic toxicity is very low. If gel is accidentally swallowed (for example, by a child), seek medical advice. Wipe off excess gel with tissue paper and dispose of it in household waste to prevent the medication from entering drains.
Overdose with oral diclofenac can cause serious symptoms including nausea, vomiting, abdominal pain, gastrointestinal bleeding, diarrhea, dizziness, tinnitus (ringing in the ears), and in severe cases, seizures, kidney failure, and liver damage. Treatment is supportive and symptomatic, as there is no specific antidote for diclofenac overdose. Activated charcoal may be considered if the ingestion was recent (within 1–2 hours).
What Are the Side Effects of Diclofenac?
The side effect profile of diclofenac depends significantly on the formulation used. Topical gel has a much more favorable safety profile than oral tablets due to its minimal systemic absorption. The following section describes side effects primarily for the topical gel formulation, with notes on additional systemic risks relevant to oral use. Like all medications, diclofenac can cause side effects, but not everyone experiences them.
Stop using diclofenac and seek medical help immediately if you experience: skin rash with blisters; wheezing, shortness of breath, or chest tightness (asthma); swelling of the face, lips, tongue, or throat. These may be signs of a serious allergic reaction.
Common
- Skin rash: Redness, scaling, or irritation at the application site
- Itching (pruritus): Localized itching at or near the treated area
- Contact dermatitis: Inflammatory skin reaction including redness and eczema
- Erythema: Redness of the skin at the application site
Uncommon
- Dry skin: Dryness and scaling at the treated area
- Localized swelling (edema): Mild swelling at the application site
- Skin peeling: Flaking or peeling of the skin where the gel was applied
Very Rare
- Bullous dermatitis: Skin rash with raised, fluid-filled blisters
- Photosensitivity: Exaggerated sunburn-like reaction on treated skin exposed to sunlight
- Gastrointestinal symptoms: Stomach discomfort or nausea (with extensive use over large areas)
- Generalized allergic reactions: Hives (urticaria) or more widespread skin reactions
- Asthma (bronchospasm): Wheezing or difficulty breathing, particularly in aspirin-sensitive individuals
- Angioedema: Swelling of the face, lips, tongue, or throat
Frequency Not Known
- Burning sensation: A burning or stinging feeling at the application site
- Skin dryness: Persistent dry skin at the treated area
When diclofenac gel is applied over large skin areas or for prolonged periods, systemic side effects similar to those seen with oral diclofenac cannot be fully excluded. These may include effects on the kidneys, liver, gastrointestinal tract, and hypersensitivity reactions. For this reason, the gel should be used at the lowest effective amount and for the shortest duration necessary.
For oral diclofenac, the side effect profile includes a broader range of systemic effects. The most common systemic side effects include gastrointestinal disturbances (nausea, vomiting, diarrhea, abdominal pain, dyspepsia, flatulence), headache, and dizziness. More serious but less common risks include gastrointestinal ulceration and bleeding, cardiovascular events (myocardial infarction, stroke), hypertension, renal impairment, and hepatic injury. These risks are generally dose-dependent and increase with duration of use.
If you experience any unexpected symptoms while using diclofenac, even if they are not listed here, stop using the product and report them to your doctor or pharmacist. You can also report suspected side effects to your national pharmacovigilance authority (for example, the MHRA Yellow Card scheme in the UK, the FDA MedWatch program in the US, or the EMA EudraVigilance system in Europe).
How Should You Store Diclofenac?
Proper storage of diclofenac is important to maintain its effectiveness and safety. The following guidelines apply to all formulations unless the product packaging specifies otherwise:
- Temperature: Store at room temperature. No special temperature requirements for the gel formulation, though it should not be exposed to excessive heat. Eye drops may have specific storage requirements; check the product label.
- Packaging: Keep the gel in its original aluminum tube with the cap securely closed after each use. The gel is light-sensitive, so storage in the original packaging helps protect it from degradation.
- Light protection: Protect from direct sunlight and strong artificial light. This is particularly important for the gel formulation.
- Child safety: Keep all medicines securely out of the sight and reach of children. Measures should be taken to prevent children from touching areas where the gel has been applied.
- Expiry date: Do not use diclofenac after the expiry date stated on the carton and tube (marked "EXP"). The expiry date refers to the last day of that month.
- Disposal: Do not dispose of medications via household waste or down drains. To prevent unused gel from reaching waterways, wipe excess gel with tissue paper and dispose in household waste. Return unused or expired tubes to your pharmacy for safe disposal.
For eye drops, check the product label for the recommended use-by period after first opening. Most ophthalmic solutions should be discarded 4 weeks after opening to reduce the risk of microbial contamination, unless otherwise specified by the manufacturer.
What Does Diclofenac Contain?
All diclofenac products contain diclofenac as the active pharmaceutical ingredient, either as diclofenac diethylamine (in topical gel formulations) or diclofenac sodium (in tablets and eye drops). The inactive ingredients (excipients) vary by formulation and manufacturer.
Topical Gel (11.6 mg/g)
Active ingredient: Diclofenac diethylamine 11.6 mg per gram, equivalent to 10 mg diclofenac sodium per gram.
Inactive ingredients: Carbomer (thickening agent), cocoyl caprylocaprate, macrogolcetostearyl ether, liquid paraffin, diethylamine, isopropyl alcohol, propylene glycol (E1520), fragrance (containing benzyl alcohol, citral, citronellol, coumarin, eugenol, farnesol, geraniol, d-limonene, and linalool), and purified water.
This gel contains propylene glycol (50 mg per gram of gel), which may cause skin irritation in some individuals. The fragrance ingredients, including benzyl alcohol (0.15 mg/g), citral, citronellol, coumarin, eugenol, farnesol, geraniol, d-limonene, and linalool, may cause allergic reactions. Benzyl alcohol may also cause mild local irritation. If you have known allergies to any of these substances, consult your pharmacist before use.
Enteric-Coated Tablets (25 mg)
Active ingredient: Diclofenac sodium 25 mg per tablet.
Typical inactive ingredients: Microcrystalline cellulose, lactose monohydrate, maize starch, colloidal anhydrous silica, magnesium stearate, and an enteric coating (typically based on methacrylic acid copolymer) that prevents dissolution in the acidic environment of the stomach.
Eye Drops (1 mg/ml)
Active ingredient: Diclofenac sodium 1 mg per ml (0.1% solution).
Typical inactive ingredients: Boric acid, tromethamine (trometamol), polyoxyl 35 castor oil, disodium edetate, water for injections, and a preservative (such as benzalkonium chloride in multi-dose formulations). Preservative-free single-dose units are also available for patients sensitive to benzalkonium chloride or those who wear contact lenses.
Appearance and Packaging
Diclofenac gel is a white to near-white, homogeneous gel packaged in aluminum-laminated tubes with a PE seal and PP screw cap. Available tube sizes typically include 30 g, 50 g, 60 g, 100 g, 120 g, and 150 g, though not all sizes may be marketed in every country. If you have known allergies to any specific excipients, always check the full ingredient list on the product packaging before use.
Frequently Asked Questions About Diclofenac
Yes, diclofenac gel (typically at 1% or 1.16% concentration, equivalent to 11.6 mg diclofenac diethylamine per gram) is available over the counter without a prescription in most countries, including the UK, EU member states, Australia, and the United States. It is approved for the short-term relief of mild to moderate pain associated with muscle and joint injuries such as sprains, strains, and sports injuries in adults and adolescents over 14. Oral diclofenac tablets and eye drops generally require a prescription, though regulations vary by country. Always check local regulations and consult a pharmacist if unsure.
The key difference lies in how the drug is delivered and how much enters the bloodstream. Diclofenac gel is applied topically to the skin over the painful area and works locally, with only about 6% of the applied dose reaching the systemic circulation. This means it provides effective local pain relief and anti-inflammatory action while carrying a significantly lower risk of systemic side effects such as gastrointestinal bleeding, cardiovascular events, and kidney problems. Oral diclofenac tablets, on the other hand, are absorbed into the bloodstream through the digestive tract and provide systemic anti-inflammatory effects throughout the body, making them more suitable for widespread conditions like rheumatoid arthritis, but with a correspondingly higher risk of systemic adverse effects. The gel is ideal for localized soft tissue pain, while tablets are used for more widespread or severe inflammatory conditions under medical supervision.
Diclofenac gel must not be used during the last three months of pregnancy (third trimester), as all NSAIDs can cause serious harm to the unborn baby during this period, including premature closure of the ductus arteriosus (a vital blood vessel in the fetal heart), reduced fetal kidney function, and complications during delivery. During the first six months of pregnancy, diclofenac gel should only be used when absolutely necessary and only on the advice of a doctor, at the lowest effective dose for the shortest possible duration. Although the topical gel has lower systemic absorption than oral NSAIDs, a precautionary approach is recommended during pregnancy. Always consult your doctor or midwife before using any medication, including topical products, during pregnancy.
Diclofenac gel typically begins to provide noticeable pain relief within 30 to 60 minutes of the first application. However, the full anti-inflammatory benefit develops gradually with regular use over several days. For optimal results, apply the gel consistently 3 to 4 times daily as directed. Most clinical studies show significant improvement in pain and swelling within 3 to 5 days of regular use. If your symptoms do not improve after 7 days of consistent use, or if they worsen at any point, discontinue the gel and consult a healthcare professional for further evaluation.
Yes, diclofenac (whether used as a topical gel or oral tablet) can generally be taken alongside paracetamol (acetaminophen) for enhanced pain relief. Since diclofenac (an NSAID) and paracetamol work through different pharmacological mechanisms, combining them can provide more effective pain control than either medication alone. This combination approach is commonly recommended by healthcare professionals and is well-supported by clinical evidence. However, you should never combine diclofenac with other NSAIDs (such as ibuprofen, naproxen, or aspirin used for pain relief), as this increases the risk of side effects without providing meaningful additional benefit. Always follow the dosing instructions for each medication separately.
Oral diclofenac, when used at full therapeutic doses (typically 150 mg/day), has been associated with an increased risk of serious cardiovascular events, including myocardial infarction (heart attack) and stroke. The landmark Coxib and traditional NSAID Trialists' (CNT) Collaboration meta-analysis, published in The Lancet in 2013, found that the cardiovascular risk of diclofenac at 150 mg/day was comparable to that of COX-2 selective inhibitors (coxibs). This risk is dose-dependent and increases with duration of use. For topical diclofenac gel, the cardiovascular risk is substantially lower because systemic absorption is minimal (approximately 6% of the applied dose). People with known cardiovascular disease, previous heart attack or stroke, uncontrolled high blood pressure, or multiple cardiovascular risk factors should discuss alternative treatments with their doctor before using oral diclofenac.
References
This article is based on current international medical guidelines, regulatory documents, and peer-reviewed research. All sources meet evidence level 1A standards.
- World Health Organization (WHO). WHO Model List of Essential Medicines – 23rd List. Geneva: WHO; 2023. Diclofenac is listed as an essential medicine for pain and palliative care.
- European Medicines Agency (EMA). Diclofenac – Summary of Product Characteristics. EMA/CHMP; 2024. Comprehensive regulatory document covering indications, dosing, contraindications, and safety data for all formulations.
- U.S. Food and Drug Administration (FDA). Diclofenac Sodium Prescribing Information and Drug Safety Communication. FDA; 2023. Includes cardiovascular and gastrointestinal risk warnings.
- Joint Formulary Committee. British National Formulary (BNF) – Diclofenac Monograph. London: BMJ Group and Pharmaceutical Press; 2024. Evidence-based prescribing reference for UK healthcare professionals.
- Coxib and traditional NSAID Trialists' (CNT) Collaboration. Vascular and upper gastrointestinal effects of non-steroidal anti-inflammatory drugs: meta-analyses of individual participant data from randomised trials. The Lancet. 2013;382(9894):769-779. doi:10.1016/S0140-6736(13)60900-9
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Editorial Team
This article has been written and reviewed by the iMedic medical editorial team according to our strict editorial standards. Our team consists of licensed physicians, pharmacists, and medical researchers with expertise in clinical pharmacology, rheumatology, and pain management.
Content developed by iMedic's medical writing team based on current international guidelines (WHO, EMA, FDA, BNF, NICE) and peer-reviewed pharmacological research.
Independently reviewed and fact-checked by the iMedic Medical Review Board, comprising board-certified specialists in clinical pharmacology and rheumatology.
All medical claims are supported by Level 1A evidence (systematic reviews, meta-analyses, and randomized controlled trials) following the GRADE evidence framework.
iMedic receives no commercial funding from pharmaceutical companies. All content is editorially independent with no conflicts of interest.