Voltaren Gel: Does It Work?

by admin

The science of the topical pain-killers, which can be effective without dosing your entire system

Voltaren® Gel (topical diclofenac) is a particularly safe and useful medicine. It’s an anti-inflammatory cream, so it can be applied only where you need it, instead of soaking your entire system with a medication, avoiding or dramatically reducing common side effects like indigestion, as well as some serious safety concerns associated with oral diclofenac. In the US, this drug is FDA-approved to treat osteoarthritis in “joints amenable to topical treatment, such as the knees and those of the hands,” but it probably also works for some other painful problems, such as some repetitive strain injuries and back pain. The evidence shows that it “provides clinically meaningful analgesia.” So this product actually works and gets a pass from skeptics and critics — a rare thing in the world of pain treatments!

Other topical analgesics are a mixed bag. The salicylates are likely effective but have more safety concerns (salicylate poisoning isn’t rare). The spicy-hot creams (Tiger Balm etc) won’t work miracles but may have some surprisingly benefits. Arnica creams are largely useless, especially the homeopathic preparations.

Think of Voltaren® Gel as “ibuprofen in a gel.” It’s actually the drug diclofenac, but ibuprofen is a much more familiar drug name in North America, where the product is still relatively new. It’s a topical anti-inflammatory medication,NSAID and FDA-approved to treat osteoarthritis in “joints amenable to topical treatment, such as the knees and those of the hands.”1 The evidence shows that it “provides clinically meaningful analgesia,” and quite safely, a claim that has been repeatedly validated by extensive testing over many years now.234

This is an appealing treatment idea that actually works reasonably well: what a pleasure to be able to say that!5 It is undoubtedly one the best of the OTC pain-killers.

Why is Voltaren mainly for joints, and only some joints?

When the FDA refers to joints that are “amenable to topical treatment,” what do they mean? Is an amenable joint friendly and easy-going? No, just accessible: a pain-killing gel is useful only for joints that are not covered by a thick layer of muscle (like the shoulder). The medication gets diluted as it penetrates deeper into tissue, and a meaningful amount can only get into joints if they are just under the surface of the skin. The shoulder, hip, and spinal joints are notably quite deep.6

For more superficial joints, though, Voltaren® Gel delivers a good dose of medication, while sparing the gastrointestinal tract from the harshness of NSAIDs — which are known as “gut burners,” because many people just can’t stomach ibuprofen. A topical drug mostly eliminates the risks associated with digesting the stuff.7

More conditions Voltaren might be good for (unofficially)

There are probably some good uses for Voltaren® Gel above and beyond what it’s already been specifically approved for (“off-label” uses). Here are some of the common conditions that, in my opinion, are also likely to be good targets for this drug.8

But I am not a doctor, and safety first: please check with your doctor before you start spreading topical diclofenac on painful problems it isn’t made for! (Especially if you already take several other drugs, or have complex medical issues.)

iliotibial band syndrome
patellofemoral syndrome
plantar fasciitis
shin splints (particularly medial tibial stress syndrome)
most common tendinitises,9 especially where the tendon is just under the skin, such as …
- tennis elbow (lateral epicondylitis)
- Achilles tendinitis
- patellar tendinitis
- carpal tunnel syndrome
- ligament sprains
acute muscle strains
bursitis
some neck pain and headaches10
sacroiliac joint pain, and possibly low back pain in general (more on this below, because it’s not obvious why Voltaren might be useful for back pain)

A personal success with Voltaren

In summer 2018 I had my first personal experience with dramatic relief from Voltaren. It’s not the first time I have found it useful, but it was the first time it was kind of amazing.

I’d been having some unexplained knee pain intermittently for several weeks when it kicked up a notch or two and became constant and even started waking me up at night. When I finally remembered to try Voltaren Gel — I’m not sure what took me so long — things were bad enough that it was going to be obvious if it worked. And it was!

After many days of constant discomfort ranging from 3-6 on a 10-scale, it just ended: half an hour after applying the stuff, I simply didn’t have that problem anymore. Hallelujah! Although the pain was not terrible, this is actually one of the clearest examples of pain relief from any treatment that I’ve ever enjoyed.

Availability and related drugs: different forms and cheaper generic versions)

Topical diclofenac is now widely available without a prescription in most places around the world. It was first available over-the-counter in the United States in early 2020, after being a prescription drug since 2007. Most other countries made it available without a prescription long before the US did (the FDA has a laudable history of being cautious with drug approval).

Topical diclofenac is now sold with several other major brand names and forms in addition to Voltaren Gel: Flector, Pennsaid, Rexaphenac, and Solaraze. There are also diclofenac patches, creams, and sprays.

Oral dicofenac has been around decades, and has been widely used globally since the 90s, and it continues to be prescribed frequently despite major safety concerns in recent history. More on this below.

Generic topical diclofenac has arrived! The first generic (cheaper) equivalent of Voltaren® Gel entered the marketplace in 2016, produced by Amneal Pharmaceutical, and that should be for sale most places now. There’s a rack of tubes of Voltaren by the till at my neighbhourhood drugstore, and I suspect pretty much every drugstore everywhere by now.

Voltaren for back pain too? Maybe! Surprisingly

I’ve emphasized that Voltaren is mainly appropriate for shallow inflammation, but there is some evidence that Voltaren might be able to “reach deeper.” This is hardly the stuff of medical certainty yet, but researchers Huang et al found that Voltaren treated pain coming from deep inside the spine, right in the centre.11

Photograph of a man holding his painful back.

Surprisingly, Voltaren may even help some kinds of deep back pain.

They concluded that it could be a “convenient and safe clinical intervention” for a few types of back pain. An anti-inflammatory gel will likely fail with many kinds of back pain, but there’s also virtually no down-side to trying. See my low back pain tutorial for extremely detailed information about medications for back pain.

However, it probably does not work well for deeper tissues in most cases.

For instance, there’s evidence that it doesn’t work at all for the muscle soreness that follows unfamiliar exercise intensity,12 probably because it can’t be absorbed far enough into thick muscle tissue — but oral NSAIDs do have a modest effect on that kind of pain1314 (one of the only things that does).

Voltaren Gel is probably better than ice

Ice is nice. I have some extremely thorough icing advice on this website.15 But Voltaren® Gel strikes me as being, well, better — definitely more evidence based.16 Or at least more convenient.

Obviously icing for pain relief has some advantages. It’s free, other than the cost of running your freezer. It’s extremely safe. And “natural.”17 But Vitamin I (for “ibuprofen”) in a gel? C’mon! That’s just awesome! Medication delivered straight to the inflamed tissues, and only the inflamed tissues … it’s kind of futuristic.

There’s no reason not to use both, of course. But Voltaren® Gel has the potential to make ice obsolete as a treatment choice, except for situations where you don’t have any Voltaren® Gel handy.

On the other hand, no medication is completely risk-free.

What do the skeptics say?

Many readers assume that “skeptics” will always favour mainstream and pharmaceutical treatments like Voltaren, but nothing could be further from the truth. Indeed, some skeptics are leading the charge against bad pharmaceutical industry science and practices (and a great example is Ben Goldacre’s new book, Bad Pharma: How drug companies mislead doctors and harm patients).

Pharmacist Scott Gavura of Science-Based Pharmacy was certainly skeptical about topical NSAIDs like Voltaren when he first tackled the topic early in 2011.18 “When I recently noticed a topical NSAID appear for sale as an over-the-counter treatment for muscle aches and pains … I was confident it would make a good case study in bad science.”

He was surprised, however, and he changed his mind when he read the evidence. Having worked with Scott as an editor, I know he can’t be persuaded by anything less than robust evidence. On a few occasions, Scott has proven himself to be even harder to impress than I am (which is really saying something). He concludes:

Over the past two decades, evidence has emerged to demonstrate that topical versions of NSAIDs are well absorbed through the skin and reach therapeutic levels in synovial fluid, muscle, and fascia. …

For chronic conditions like osteoarthritis, the data are of fair quality and are persuasive. On balance, there’s good evidence to show that topical NSAIDs are clinically- and cost-effective for short term (< 4 weeks) use, especially when pain is localized.

Nothing’s perfect, however, and some concerns about Voltaren are covered below.

Where’s the fire? Treating “inflammation” may be a bad premise in many cases

Are you sure that you’re actually inflamed? Don’t answer too quickly.

One concern about the use of products like Voltaren is that several conditions may be less inflammatory in nature than they seem like. Patients usually assume that the “burning” pain of repetitive strain injuries like tendinitis is caused by inflammation. Seems reasonable.

But classic, acute inflammation is almost entirely absent, especially after initial flare-ups have died down (but pain is still carrying on).

While it is extremely likely that tendinitis is still inflamed in some sense,19 it’s somewhat doubtful that they are inflamed in a way that NSAIDs are actually good for. The biochemistry of cranky tendons is very “here be dragons” on the map of biology — large and unexplored. There’s probably some overlap between the biology of acute, classic inflammation and the subtler biology of chronic tendinitis, but no one really knows.

So the value of Voltaren for tendinitis is simply unclear. You can read about this in much greater detail in my RSI article: Repetitive Strain Injuries Tutorial: Five surprising and important facts about repetitive strain injuries like carpal tunnel syndrome, tendinitis, or iliotibial band syndrome

Don’t forget that exercise is also an anti-inflammatory medication

Note that moderate exercise is almost certainly anti-inflammatory as well.20 Which is cool.

Never just use Voltaren (or any pain-killer). Ideally, even the safest pain-killer should only be used sparingly, and to make it easier to exercise — whatever exercise you can do without excessive discomfort.21 Even if you’re really hurting, you may still be able to do easy pain-free range of motion exercises. Just beware of overdoing it while medicated!

How diclofenac works

Diclofenac suppresses inflammation, fever, and pain mainly by blocking production of prostaglandins, a signalling molecule involved in a huge array of biological processes — which is how all the NSAIDs work, broadly speaking.

What seems to be different about diclofenac is that it’s better at doing NSAID-ish things than other NSAIDs. For instance, it may inhibit prostaglandin-making in both of the two common ways, whereas all the other NSAIDs are either one or the other. But the biochemistry is dazzlingly complex, and there are several other possible mechanisms (and mysteries) for making it more potent (and dangerous).

The drug is active biologically for just an hour or two as traditionally measured, but when absorbed into the synovial fluid of joints, it sticks around for least ten hours, which may account for why it particularly makes a difference for arthritis pain.

3D ball-and-stick representation of a Diclofenac molecule

More about safety, and the trouble with oral diclofenac

Long term and/or large oral doses of any of the NSAIDs can be extremely dangerous, even lethal. They “nuke” your entire system with much more active ingredient than you really need, all of it absorbed through the digestive tract and distributed through your entire circulatory system.

These drugs can and do cause complications at any dose, and are linked to heart attacks and strokes and ulcerations of the GI tract. What a bunch of jerks!

But oral diclofenac is a special kind of awful.

Diclofenac is an extremely popular drug and it is also associated with serious cardiovascular risks. McGettigan et al:22

There is increasing regulatory concern about diclofenac. … Diclofenac has no advantage in terms of gastrointestinal safety and it has a clear cardiovascular disadvantage.

This has been in the news quite a bit, and NPR had a hit in 2013 with this headline: “World’s Most Popular Painkiller Raises Heart Attack Risk.” And it’s not wrong, that headline. It’s not hype and alarmism — there is a real problem.

Topical diclofenac is a completely different animal than oral

The difference between oral and topical is extremely important. Spreading a medication on your skin is not the same thing as swallowing it.

Because Voltaren Gel is applied to the skin, dramatically less medication reaches the bloodstream — only a tiny fraction of what you would get from oral usage.2324 It is safe to assume that cardiovascular risks of moderate topical use are negligible compared to oral diclofenac, because so much less medication is actually getting into general circulation, and that is what the evidence now shows.25 Multiple studies have concluded that topical NSAIDs are both effective and safe.262728

At correct dosages for limited time periods, I think Voltaren Gel is probably almost completely safe: the worst side effect is probably the chance of irritated skin. ScienceBasedMedicine.org agrees:29

The main advantage of topical NSAIDs is the reduced exposure of the rest of the body to the product, which reduces the side effect profile. Given the toxicity of NSAIDs is related in part to the dose, it follows that topical treatments should have a better toxicity profile. Consequently, the cardiovascular risks of topical diclofenac, even in those with a high baseline risk of disease, should be negligible with the topical forms.

Some skin side effects for some people

I am definitely not saying Voltaren is completely safe or risk free. No drug is. The drug is still being absorbed, but instead of being a “gut burner” it can be a “skin burner.” From the Voltaren® Gel website …

The most common adverse reactions reported in Voltaren Gel clinical trials were application site reactions in 7% of treated patients. With all NSAIDs there may be an increased risk of serious cardiovascular thrombotic events, myocardial infarction, and stroke, which can be fatal.

Sounds bad, doesn’t it? But those warnings are primarily there in an abundance of legal and medical caution provoked by the problems with oral NSAIDs. For short-term, moderate topical use, I believe the benefits clearly outweigh the minor risks.

What about long-term use?

This drug was basically invented as an arthritis treatment. Those patients may be interested in using topical diclofenac regularly and indefinitely. Is that kind of long term usage safe? Is regular use of any medication a good idea?

There is no good data on long term safety that I’m aware of. It probably doesn’t exist yet.

In principle, long-term use of any medication should be minimized as much as possible. The benefits of topical diclofenac aren’t so great that they justify the risks of frequent use indefinitely.

If I wished I could use it that way, I’d probably plan to take usage breaks: just stop using it for a while, a few times a year.

On the other hand, it’s probably about as safe for regular use as any medication gets. But that’s just an educated guess, extrapolating from the short term safety data.