What to Know About Voltaren Gel

Voltaren Gel (diclofenac) is a topical nonsteroidal anti-inflammatory drug (NSAID) and the first prescription topical treatment for osteoarthritis approved by the Food and Drug Administration (FDA). It is also used to treat actinic keratoses and is mostly used on the knees and hands.

Before Taking

If you think you may be a candidate for Voltaren Gel, discuss it with your doctor to determine if it's appropriate for you. People who've experienced gastrointestinal side effects from oral NSAIDs are often considered as candidates for switching to Voltaren Gel.

The systemic absorption of Voltaren Gel, which is 1 percent diclofenac sodium in a topical gel formulation, is 94 percent less than oral diclofenac. That means the risk of serious gastrointestinal and cardiovascular side effects that are associated with oral NSAIDs is considerably less with the topical formulation.

The FDA approval was based on several studies, including two randomized, double-blind, placebo-controlled efficacy studies and a 12-month safety study. After six weeks of treatment in an efficacy study of people with hand osteoarthritis, pain levels were reduced by 46 percent. In a 12-week study of people with knee osteoarthritis, Voltaren Gel reduced pain levels by 51 percent.

Talk to your doctor about all medications, supplements, and vitamins that you currently take. While some drugs pose minor interaction risks, others may outright contraindicate use or prompt careful consideration as to whether the pros of treatment outweigh the cons in your case.

Black Box Warnings

Black box warnings alert physicians and patients to the most severe possible side effects. Voltaren Gel has two black box warnings that are common to all NSAIDs.

Serious side effects can happen without warning. Your risk may be higher if you've been taking NSAIDs for a long time or at high dosages.

If you are at risk for cardiac events and stroke, you should not take this medication. It should not be used for pain relief before or after coronary artery bypass graft surgery (CABG) either.

You're more at risk for gastrointestinal side effects if you are elderly or have a history of peptic ulcer disease or gastrointestinal bleeding.

Contraindications

Besides the groups at increased risk listed in the black box warnings, Voltaren Gel should not be used by people with:

• Known hypersensitivity to diclofenac
• People who developed asthma, urticaria, or allergic reactions after taking aspirin or NSAIDs
• Women trying to get pregnant, as it can cause delayed ovulation, which should go away after you stop using the medication
• Pregnant women after 30 weeks gestation, as it may cause a fetal heart defect

Dosage

Voltaren Gel should be measured onto the reusable dosing card which is enclosed—measure to the appropriate 2-gram or 4-gram mark. Never use more than the prescribed amount.

The total dose of Voltaren Gel should not exceed 32 grams per day over all of the affected joints.

Application:

• For lower extremities, apply 4 grams of the gel to the affected area four times daily. Do not apply more than 16 grams daily to any one joint of the lower extremities.
• For upper extremities, apply 2 grams of the gel to the affected area four times daily. Do not apply more than 8 grams daily to anyone affected joint of the upper extremities.

How to Take and Store

Avoid getting this medication in your eyes, mouth, open wounds, or infected areas. Unless you're applying it to your hand joints, wash your hands immediately after application.

Side Effects

The most common adverse reactions reported in clinical trials were application site reactions in 7 percent of study participants treated with Voltaren Gel.

Hypertension can also occur with NSAID treatment, making it important to monitor blood pressure. Fluid retention and edema may occur as well.

If an allergic reaction occurs, stop using it immediately.

Severe

The prescribing information for Voltaren Gel provides warnings and precautions for serious adverse reactions as well.

Long-term administration of NSAIDs can result in renal (kidney) papillary necrosis and another renal injury. NSAIDs can cause serious skin side effects, too, including exfoliative dermatitis, Stevens-Johnson syndrome, and toxic epidermal necrolysis, which can be fatal.

The elderly, people with impaired renal function, heart failure, liver dysfunction, and those taking diuretics and ACE inhibitors should be cautious when using Voltaren Gel.

In 2009, the FDA updated the label for Voltaren Gel to include information about possible hepatic (liver) effects. It now reads: "In post-marketing reports, cases of drug-induced hepatotoxicity have been reported in the first month, and in some cases, the first two months of therapy, but can occur at any time during treatment with diclofenac.

"Post-marketing surveillance has reported cases of severe hepatic reactions, including liver necrosis, jaundice, fulfillment hepatitis with and without jaundice, and liver failure. Some of these reported cases resulted in fatalities or liver transplantation...

"Physicians should measure transaminases periodically in patients receiving long-term therapy with diclofenac, because severe hepatotoxicity may develop without a prodrome of distinguishing symptoms."

Interactions

Voltaren Gel should not be used together with oral NSAIDs or aspirin because of an increased risk of adverse events. The risk of side effects increases with the increased absorption of the active ingredients in NSAIDs.

Just as topical NSAID cream should not be used with oral NSAIDs, two different oral NSAIDs should not be taken together. Talk to your doctor about using low-dose aspirin.

Skin Products

If you're using cosmetics or sunscreen, don't use Voltaren Gel at the same time. The combinations have not been tested and, if topical agents are combined, there is the potential to change how Voltaren Gel is tolerated and absorbed. 

A Word From Verywell

The more treatment options there are for people with arthritis, the better. And the availability of a topical formulation of Voltaren is important for people who can't tolerate oral NSAIDs for one reason or another.

Just be aware that both oral and topical NSAIDs carry the same risks, and that Voltaren shouldn't be combined with other NSAIDs.