Often used in gel or tablets, diclofenac (Voltarene) is an anti-inflammatory indicated to relieve muscle pain. It is on the list of medications to avoid according to the medical journal Prescrire.
Diclofenac is a anti-inflammatory substance present in particular in the famous Voltarene. Her oral form is listed on the 2023 list of drugs to be ruled out according to the medical journal Prescribe due “an increase in adverse cardiovascular effects (including myocardial infarction, heart failure) and cardiovascular deaths compared to other NSAIDs as effective”.
What is diclofenac?
Diclofenac is a nonsteroidal anti-inflammatory therapy “whose main indication is in rheumatology or in the inflammatory syndromes to get relief from symptoms such as joint pain“ explains pharmacist Martial Fraysse. “Apart from being somewhat less effective in migraine than ketoprofen, it is the ketoprofen twin brother“, continues Pascal Chazerain, head of the department of rheumatology in Paris. “Old molecules, these are also the two most prescribed anti-inflammatories for a very long time“.
In what drugs?
The best known trade name is Voltaren®.
“Diclofenac acts by an anti-inflammatory action“, explains the rheumatologist, “that is, by a anti-prostaglandin action : it inhibits the synthesis of prostaglandins which are molecules that maintain or promote inflammation“.
Which gel indications?
Diclofenac is indicated in gel for superficial pain because it has a penetrating power of a few millimeters. It will therefore be prescribed for:
- of osteoarthritis superficial joints
- of the tendonitis
- of the local subcutaneous inflammationson the occasion of benign trauma
In gel, Voltarene® is less dangerous… provided do not put too much and do not spread it over very large quantities. Otherwise “there is a quantity of diclofenac that can pass into the blood and you can have general effects like those found with the tablets” notify the pharmacist. Not considering “the freeze dries out the skin and removes the lipid film which increases the risk of skin problems”. Finally, he is recommended not to expose the treated area with gel, to the sun.
Trick : There is a very easy and very practical way to use Voltarene® gel: “You put a layer of it on the area that hurts at the joint level and you put a cling film above, this constitutes an occlusive environment and makes the product penetrate much more, indicates the pharmacist. If you do this, also bring back the film used in the pharmacy with the expired drugs so as not to pollute by throwing it in the trash.”
What are the dangers of diclofenac?
Voltarene® can become dangerous through its mode of action on prostaglandins. Moreover on long takes (several months). “Prostaglandins are involved in the process of inflammation, argues Martial Fraysse. The big difficulty is that there are prostaglandins that protect the mucous membranes, such as the stomach, and others that contribute to inflammation. However, the drugs are not always selective, some act on both types of prostaglandins in question, some only affect one. According to him, Voltarene® “has more benefits than risks” and “sometimes you have to prefer another anti-inflammatory”. This is also the opinion shared by the authors of the independent medical journal Prescrire who include diclofenac per route on their list of drugs to be avoided. They indicate that he exposes to “an increase in adverse cardiovascular effects (including myocardial infarction, heart failure) and cardiovascular deaths compared to other NSAIDs as effective”.
What is the cardiovascular risk with diclofenac?
Like all NSAIDs, diclofenac medicines have a “well-known cardiovascular risk” reminded theMedicines Agency in a press release in 2018. A study conducted in Denmark on diclofenac showed a higher risk of cardiovascular events even at low doses and for short periods of use (30 days) compared to other treatments (paracetamol, ibuprofen, naproxen). “If you take diclofenac, especially for months, you can have thrombosesof the stroke, confirms the pharmacist. It has this paradoxical effect: instead of thinning the blood like all non-steroidal anti-inflammatory drugs – that’s why they should never be combined with aspirin – it can make coagulate faster in long-term use.” This “abnormal” clotting“promotes the formation of blood clots and amplifies cardiovascular complications.
Attention : Medications containing diclofenac are thus contraindicated in patients with cardiovascular disease (proven congestive heart failure, ischemic heart disease, peripheral arterial disease and/or cerebrovascular disease).
Can diclofenac cause gastrointestinal bleeding?
“Medicines based on diclofenac such as Voltarene® decrease the prostaglandins which protect the stomach so we are likely to have digestive bleeding even in the short term, after about ten days“ notify the pharmacist. This risk primarily concerns oral intake: “In gel form, it’s rarer to have gastrointestinal problems.”
Reminder : NSAIDs should always be taken with meals. “If he deems it necessary, the doctor can accompany it with a drug that reduces the acidity of the stomach in order to avoid gastric side effects” recalls Martial Fraysse.
What are the possible side effects ?
“There are twice as many side effects with diclofenac as with some other nonsteroidal anti-inflammatory drugs” announces Martial Fraysse. So be careful with this drug. “Of the heartburnof the skin rashes signs of allergy, if you see blood in the stool or that one has a hemorrhoidal crisis which is complicated, talk to your doctor or pharmacist about it. details the specialist. Voltarene® can also increase blood pressure even on a short take and “exacerbate asthma“. These side effects explain why diclofenac cannot be given on a long-term basis and/or in too high doses.
What injection indications?
Intramuscular injection allows for a faster onset of action only when taken orally. “At the hospital, in the emergency room, it will be indicated in this form, for a attack of renal colic for example, in order to relieve the patient as soon as possible“.
What dosage?
Several dosages exist for diclofenac: 25mg, 50mg, 75mg or 100mg. The dosage is chosen depending on the patient’s weight, age and pathology.
“The patient should always look at what the drug is doing to them.”
What contraindications?
- Voltarene® and its generics are contraindicated for pregnant and breastfeeding women, even in gel as there is a transcutaneous passage.
- Diclofenac-based drugs are contraindicated in patients with cardiovascular disease (proven congestive heart failure, ischemic heart disease, peripheral arterial disease and/or cerebrovascular disease).
- “Someone who is renal failure should not take it especially in tablets because they are quite toxic for the kidneys like all NSAIDs”, recalls Martial Fraysse.
- “The anti-inflammatory increases the risk of bleeding and so if there is already a digestive ulcerlikely to bleed, it will make it worse and if there is already anticoagulant treatment, it is likely to increase the risk of a complication“, specifies Doctor Chazerain.
What precautions?
It is necessary to respect the dosage indicated by the doctor and the duration of a treatment with diclofenac. In gel, the pharmacist is able to advise you. For Martial Fraysse “the patient must always look at what the drug does to him. If he has more side effects than therapeutic effects, it is obvious that he must warn his pharmacist or his doctor to stop it.”
Can we give diclofenac to children?
“Voltarène® can be given a few times in cases of ankylosing spondylitis in young children with dose adjustments” indicates our interlocutor. It is then Voltarène25® which is authorized in more than 6 yearsApart from this case, diclofenac-based drugs are not allowed in children under less than 35 kg.
Thanks to Martial Fraysse, doctor of pharmacy and to doctor Pascal Chazerain, head of the rheumatology department Groupe Hospitalier Diaconesses Croix Saint-Simon in Paris