Diclofenac, Diclofenac ER

Written by Sarah Lewis, PharmD
Medically reviewed by Purva Singla, PharmD
Updated on 6/30/2023

The Food and Drug Administration (FDA) has approved diclofenac for use in adults to reduce mild to moderate pain. It also helps relieve pain-related symptoms in certain conditions, including:

• menstrual cramps
• osteoarthritis
• rheumatoid arthritis
• ankylosing spondylitis
• migraine headaches
• swelling, pain, and sensitivity to light after eye surgery

These approved uses differ based on the form of diclofenac your doctor prescribes.

This article describes diclofenac’s uses, side effects, and more. You’ll also find some coupon options to help save on the cost of diclofenac.

This article doesn’t provide coupons for all forms of diclofenac. To find coupons for other forms of diclofenac, see the following articles:

• topical gel
• eye drops
• oral tablet

Boxed warnings

Diclofenac has boxed warnings about the risks of serious heart, blood vessel, and digestive system problems. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA). These boxed warnings apply to all forms of diclofenac.

For details, see the “Interactions and warnings for diclofenac” section.

Diclofenac may cause mild or serious side effects. More common mild side effects of diclofenac and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about diclofenac’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for diclofenac listed in the “Article resources” section.

Mild side effects

More common mild side effects reported with some forms of diclofenac are listed below. These side effects may differ based on the form of diclofenac you take or use.

This article doesn’t include all possible mild side effects of the drug. To learn more about diclofenac’s side effects based on the form, refer to the prescribing information for diclofenac listed in the “Article resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Diclofenac delayed-release oral tablet’s mild side effects include:

• abdominal pain
• constipation
• diarrhea
• heartburn or indigestion
• mild allergic reaction*

Diclofenac topical gel’s mild side effects include:

• skin dryness
• skin irritation
• skin itching
• skin redness
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for diclofenac” section.

Serious side effects

Serious side effects of diclofenac are listed below. These side effects may differ based on the form of diclofenac you take or use.

This article doesn’t include all possible serious side effects of the drug. To learn more about diclofenac’s side effects based on the form, refer to the prescribing information for diclofenac listed in the “Article resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, diclofenac’s serious side effects include:

• fluid retention
• high potassium levels
• kidney damage
• liver problems
• low red blood cell count
• new or worsening high blood pressure
• boxed warnings: risk of serious heart, blood vessel, and digestive problems*
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for diclofenac” section.

The Food and Drug Administration (FDA) approves prescription drugs such as diclofenac for certain conditions. Approved uses for diclofenac are described below. These uses differ based on the form of diclofenac prescribed.

Use for pain relief

Doctors may prescribe diclofenac for treating mild to moderate pain, inflammation, and swelling. It’s used for this purpose in adults. It can be prescribed as a long-term or short-term treatment.

Diclofenac can help relieve pain and inflammation from various conditions, including:

• menstrual cramps
• osteoarthritis
• rheumatoid arthritis
• ankylosing spondylitis
• migraine headache
• eye surgery

Doctors may not prescribe diclofenac oral tablet, delayed-release oral tablet, extended-release oral tablet, topical gel, topical solution, oral powder packets,* and oral capsule in certain situations. This includes if someone has just had heart bypass surgery or a heart attack.

* You’ll get these packets from your pharmacy and use the powder inside to make a solution that you’ll take by mouth.

Below you’ll find answers to a few commonly asked questions about diclofenac.

What brand names are available for diclofenac?

Diclofenac oral tablet is available as the brand-name drug Lofena. The oral capsule is available as the brand-name drug Zipsor. The oral powder packets are available as the brand-name drug Cambia.

The topical gel is available as the brand-name drug Voltaren. The topical liquid is available as the brand-name drug Pennsaid.

A generic medication is an identical copy of the active drug in a brand-name medication. (An active drug is the ingredient that makes a medication work.) Generics usually cost less than brand-name drugs. And they’re thought to be as safe and effective as the brand-name versions.

To learn more about brand-name diclofenac, talk with your doctor or pharmacist.

How does diclofenac work? And how long does it take to start working?

Diclofenac works by blocking substances in the body that cause pain, inflammation, and swelling.

How long diclofenac takes to start working can vary with the dosage form. Most oral forms will start working within 1–2 hours. These forms have a half-life of about 2 hours. A half-life refers to the amount of time it takes your body to get rid of half a dose.

The oral powder packets* are designed for faster relief and may start working within 30 minutes. The eye drops will also start to work quickly. The topical forms may take up to 7 days to provide the full pain-relieving effects.

If you’d like to know more about how diclofenac works, talk with your doctor or pharmacist.

* You’ll get these packets from your pharmacy and use the powder inside to make a solution that you’ll take by mouth.

Below, you’ll find information about diclofenac’s possible interactions and warnings.

Interactions of diclofenac

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take or use diclofenac, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for diclofenac” section below.

Warnings for diclofenac

Some people should not take or use diclofenac, and others should take or use it cautiously.

Boxed warnings

Diclofenac has boxed warnings about the risks of serious heart, blood vessel, and digestive system problems. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA). These boxed warnings apply to all forms of diclofenac.

To learn more about these warnings, read below. You can also talk with your doctor or pharmacist.

Risk of serious heart and blood vessel problems. Taking nonsteroidal anti-inflammatory drugs (NSAIDs), including diclofenac, increases the risk of serious heart and blood vessel problems. This includes heart attack and stroke. The risk can increase with long-term use and higher doses. Your risk may also be higher if you already have risk factors for heart and blood vessel problems, such as high blood pressure.

Symptoms may include:

• chest pain or discomfort
• drooping on one side of the face
• shortness of breath
• trouble speaking
• weakness or numbness on one side of the body

If you experience any of these symptoms, seek immediate medical care or call 911.

Risk of serious digestive system problems. Taking NSAIDs, including diclofenac, increases the risk of serious digestive system problems. This includes bleeding, and ulcers (sores) or holes in the esophagus, stomach, or intestines. In some cases, this can be life threatening. These problems can occur at any time during use and without warning. Older adults and people who have had ulcers or bleeding in the stomach or intestines in the past are at greater risk.

Symptoms may include:

• abdominal or stomach pain
• blood in the stool or black, tarry bowel movements
• nausea
• vomiting blood

If you experience any of these symptoms, seek immediate medical care or call 911.

Other warnings

Diclofenac could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether diclofenac is a safe option for you. These warnings may differ based on the form of diclofenac you take or use.

Ask your doctor about specific warnings for diclofenac, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Diclofenac can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to diclofenac or any of its ingredients, your doctor will likely not prescribe diclofenac. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• severe skin rashes that may blister and peel
• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to diclofenac, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of diclofenac

If you take diclofenac by mouth or apply diclofenac to your skin, you should not take or apply more than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken or used too much diclofenac, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and diclofenac

Information about diclofenac and pregnancy and breastfeeding is described below.

Diclofenac and pregnancy

Diclofenac should not be taken or used during pregnancy after week 20 of the pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking or using this medication. Your doctor may suggest birth control options to use during treatment with diclofenac.

Diclofenac and breastfeeding

It’s not known whether diclofenac should be taken or used while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking or using this medication.

This article describes diclofenac’s uses and side effects, ways to save on cost, and more. Let your doctor know if you have questions about diclofenac or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• What drug interactions should I avoid when taking diclofenac?
• Am I at higher risk of side effects than other people?
• Are there any alternative medications that could treat my condition?

• Diclofenac potassium capsule, liquid filled. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/3a837a3e-10b2-4256-b515-80c863318ccb/spl-doc
• Diclofenac potassium powder, for solution. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/2d45648f-cbea-41a4-8e3e-007b7bb7912c/spl-doc
• Diclofenac potassium tablets, USP. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/90c6d882-aea2-439a-a3c1-53255d12ae94/spl-doc
• Diclofenac sodium delayed-release tablets, USP. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/89ccfc76-245f-4604-bc1d-9115c657c340/spl-doc  
• Diclofenac sodium ophthalmic solution, 0.1%. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/5372866a-dab3-45c8-8c2a-755ca36c1791/spl-doc
• Diclofenac sodium tablet, film coated, extended-release. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/85ba4872-19db-2316-e053-2991aa0a00fc/spl-doc
• Diclofenac sodium topical solution 1.5% w/w, for topical use. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/e5f8284a-1aa9-4a36-a6ad-fa153c613f34/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.