Before using diclofenac, tell your doctor or pharmacist if you are allergic to it; or to aspirin; or to other NSAIDs (such as ibuprofen, naproxen, celecoxib); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: asthma (including a history of worsening breathing after taking aspirin or other NSAIDs), stomach/intestine problems (such as bleeding, ulcers), liver disease, heart disease (such as history of heart attack), high blood pressure, stroke, swelling (edema, water retention), blood disorders (such as anemia, bleeding/clotting problems), growths in the nose (nasal polyps).

Kidney problems can sometimes occur with the use of NSAID medications, including diclofenac. Problems are more likely to occur if you are dehydrated, have heart failure or kidney disease, are an older adult, or if you take certain medications (see also Drug Interactions section). Drink plenty of fluids as directed by your doctor to prevent dehydration and tell your doctor right away if you have a change in the amount of urine.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

If you are going to have an MRI test, tell testing personnel that you are using this patch. Some patches may contain metals that can cause serious burns during an MRI. Ask your doctor whether you will need to remove your patch before the test and apply a new patch afterward, and how to do so properly.

This medicine may cause stomach bleeding. Daily use of alcohol and tobacco may increase your risk for stomach bleeding, especially when combined with this medicine. Limit alcohol and stop smoking. Consult your doctor or pharmacist for more information.

This medication may make you more sensitive to the sun. Limit your time in the sun. Avoid tanning booths and sunlamps. Use sunscreen and wear protective clothing when outdoors. Tell your doctor right away if you get sunburned or have skin blisters/redness.

Older adults may be at greater risk for stomach/intestinal bleeding, kidney problems, heart attack, and stroke while using this drug.

Before using this medication, women of childbearing age should talk with their doctor(s) about the benefits and risks. Tell your doctor if you are pregnant or if you plan to become pregnant. This medication may harm an unborn baby and cause problems with normal labor/delivery. It is not recommended for use in pregnancy from 20 weeks until delivery. If your doctor decides that you need to use this medication between 20 and 30 weeks of pregnancy, you should use the lowest effective dose for the shortest possible time. You should not use this medication after 30 weeks of pregnancy.

This medication passes into breast milk, but is unlikely to harm a nursing infant. Consult your doctor before breastfeeding.