dangers of diclofenac

Doctors love NSAIDs (nonsteroidal anti-inflammatory drugs). That’s largely because they don’t have a lot of other tools in the toolkit when it comes to treating pain and inflammation. Opioids have been demonized and doctors have been chastised if they prescribe hydrocodone or oxycodone for chronic pain. As a result, 60 million prescriptions are dispensed annually for drugs like meloxicam, naproxen, diclofenac, celecoxib, nabumetone and indomethacin. Now a new study reports that diclofenac (Cataflam, Voltaren) is associated with serious cardiovascular complications (BMJ, September 4, 2018). What should you know about the dangers of diclofenac?

What Are the Dangers of Diclofenac?

Diclofenac is available without a prescription in most European countries. In the U.S. it is only available by prescription, though similar drugs (ibuprofen and naproxen) are sold over the counter.

Danish scientists wondered whether diclofenac carried risks similar to those of rofecoxib (Vioxx), which was pulled off the market because it was linked to excess heart attacks and strokes. They analyzed data from the Danish National Health Service which keeps records on all Danish citizens.

The study included 1.4 million people who started taking diclofenac. They were compared to 3.9 million people starting on ibuprofen, 291,000 people on naproxen, 765,000 people starting on acetaminophen (paracetamol) and 1.3 million people taking no pain relievers. Such numbers are impressive.


The researchers found that people taking diclofenac were 50% more likely to experience a serious adverse event than those who were not taking any pain relievers. The complications included the heart rhythm disturbances (atrial fibrillation or flutter), clotting strokes, heart failure, heart attacks and cardiac death. They were also more likely to experience such side effects than people taking the other pain relievers.

The dangers of diclofenac began to show up within the first 30 days of treatment. Even low doses posed a risk. This contradicts the perception that short-term treatment is safe.

The Dangers of Diclofenac for the Digestive Tract:

It’s not just the heart and cardiovascular system that’s at risk from NSAIDs. Gastroenterologists have long recognized that drugs like diclofenac, ibuprofen, meloxicam and naproxen can cause serious ulceration and hemorrhage of the stomach and small intestine. The Danish investigators noted that diclofenac and naproxen were both associated with upper gastrointestinal bleeding at a rate 4.5 times higher than that of people not taking pain relievers.


The authors concluded:

“It is time to acknowledge the potential health risk of diclofenac and to reduce its use…Our data support that initiation of diclofenac poses a cardiovascular health risk, both compared with no use, paracetamol use, and use of other traditional NSAIDs.”

Other Dangers of Diclofenac:

  • indigestion and heartburn
  • nausea and vomiting
  • stomachache
  • diarrhea
  • constipation
  • headache
  • dizziness
  • disorientation
  • rash
  • itching or hives
  • sensitivity to sunlight
  • elevated liver enzymes
  • swollen legs or feet
  • tinnitus (ringing in the ears)
  • delayed ovulation
  • digestive tract bleeding
  • perforated ulcer
  • atrial fibrillation or flutter
  • heart attack
  • stroke
  • blood clots
  • high blood pressure
  • congestive heart failure
  • kidney injury
  • liver damage
  • pancreatitis
  • anemia
  • elevated potassium levels
  • anemia
  • Stevens-Johnson syndrome

People’s Pharmacy Perspective:

The Danish investigators recommend that diclofenac should not be available over the counter. Of course, in the US it is not, but both ibuprofen and naproxen are. The Danish study showed that the risks of gastrointestinal bleeding from naproxen are equivalent to those from diclofenac. And although the cardiovascular risks of diclofenac appeared slightly higher in this study than those of ibuprofen or naproxen, all NSAIDs can cause similar harms. We hope that people will use such medications only when absolutely necessary and treat them with the respect that is due potentially deadly drugs.

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  1. Josefina

    I’m surprised not to have seen any comments about the use of topical DMSO (70% solution) for arthritic pain. I have used it for years with much gratitude to Dr. Stanley Jacob, who years ago was much criticized for discovering its usefulness for arthritic pain. Its effect on atopic dermatitis is evident in two minutes. Sometimes I have been awakened by pain on a finger joint, and all I do is rub it with a small DMSO- soaked cotton pad, and in minutes I go back to sleep. You may search for this product in OR state if you wish. Best of health to you !

  2. Michael

    I tried 1% diclofenac for osteoarthritis with no noticeable side effects. But, I didn’t think it worked as well as my homemade topical, 6 tablespoons of MSM powder dissolved in 12 ounces of aloe vera jel.

  3. Judi
    Port St. Lucie, FL

    Last year my surgeon put me on Naproxen before it became necessary for him to do neck surgery on me. On day 21 of taking Naproxen my blood pressure spiked to 234/180 and I went to the ER. I will never take NSAIDS again.

    I had back surgery 2 1/2 months ago and was put on 10 mg Percoset 4 times a day. My BP was high the whole time. I started tapering off after 2 weeks. After 2 months my BP went up to 225/112 and I went to the ER twice. I managed to completely taper off 2 weeks later and my doctor managed to save me from a stroke and get my BP back down to normal.

    Needless to say, I’m afraid of all pain meds now. I’ve just started physical therapy and am in pain. Doctor said I can take Extra Strength 500 mg Tylenol, one every 4 hrs if needed. So far I have taken just one on 2 occasions with no scary side effects. I have decided to face the pain rather than risk a stroke.

  4. Anne Skinner

    I was using Diclofenac for a month or more when I started feeling like my heart was going to stop. then I did a little research and found that it was Aleve. the little blue pill. I had the same problem with it. now I have 2 and a half tubes of Diclofenac and I can’t use it. I do better with ibuprofen but try not to use it often. This leaves me with Tylenol and thankfully, Deep Blue essential oil cream. It really helps. and oddly enough, Rosemary oil seems to help. I just rub it on my knees. Maybe different things work for different people. I saw the post above where all the person uses is Aleve.

  5. Claudia

    Why do they even make pain relief meds when they all cause other things to go wrong that is more dangerous than the pain???
    All pain meds make me sick so I don’t take any. But sometimes I still take an aspirin which is also bad, and me being on Warfarin makes it worse. I live with horrible pain every day, but what can I do, NOTHING……‼️😭😭😭

  6. Lizzie

    I took Vioxx for several years until they took it off the market. I was an RN and stood long hours at my job. I eventually had my knees replaced but continued taking Aleve at that time. I was diagnosed with A.Fib a few years later but never connected the dots. Neither did my PCP. Eventually I had a spinal fusion and was prescribed Diclofenac, and it was great for all my arthritis aches and pains. Eventually I had to start on blood thinners so had to go off all NSAIDS. Every area of arthritis was so intense. However my GI upset was gone, and A. Fib was less frequent (but the damage was done). If only my doctors would have told me what I know now. I have pain every day.

  7. Douglas

    Does diclofenac in a topical cream or gel pose a threat as well?

  8. Angela
    Vancouver, WA

    Thankfully I can’t handle any kind of opioid. But I need Advil for pain relief. I don’t take a lot of it, but it’s the only thing that will work for me. I think it’s a shame that people who really need pain relief from opioids are having a harder time getting their prescriptions. Makes me want to stock up on Advil just in case.

  9. Joan

    My Dr warned me of the dangers of these painkillers over 20 years ago so why they needed to do such a big clinical trial is beyond me.
    I control my own inflammation with regular cups of ginger tea, ice packs, and massage and for the pain I take paracetamol.
    I have found from past experience the more painkillers you take the more you need as the body gets used to them.
    Pain is the bodies way of warning you something is injured or wrong and stops you in your tracks which helps rest the affected part, diet also plays a big roll in inflammation so cutting down or better still cutting out wheat, sugar, and dairy will also ease inflammation

  10. Deborah T

    I had a foot crushed in a head-on collision in 1992 about the time Voltaren came out. I have been taking Diclofenac since it became the generic. I can take 1-2 per day but get by with one. I might take 2 a couple times a year. I am 68 and that is the only drug I have to take. All my stats are perfect. I do excercise 2 days a week and dance 2 days a week. I keep my own yard up and do a lot of digging and planting. I would hate to give up Diclofenac I always eat when I take it at break

  11. Tom

    Of course it made no sense to take Vioxx of the market and leave Diclofenac and other NSAIDs on as well as Ibuprofen and naproxen OTC. They all have the same side effect profile. Vioxx had the largest pocket for lawyers to pick.

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