Like many medications, the prescription pain reliever diclofenac is available in several different formulations, formats and dosages. However, unlike the NSAIDs that you might be used to taking over the counter, such as Advil or Aspirin, the different formulations of diclofenac are not interchangeable and are prescribed by doctors specifically to relieve symptoms in some conditions, but not others.
For that reason, it is imperative that you follow your doctor’s prescription and instructions exactly, and contact them if you have any questions or doubts about how to take your diclofenac medication.
The three main forms of delivery for diclofenac is oral, topical and intravenous. Most patients will be prescribed some oral form of this pain reliever. However, the topical form is sometimes prescribed to patients with certain types of joint pain or other conditions, such as actinic keratosis.
This NSAID medicine is usually prescribed as either diclofenac sodium or diclofenac potassium, although a third formulation called “free acid” is also available. This simply means that there is no cation (positive ion, such as sodium or potassium) to create a salt from the diclofenac, so that it retains its original form as an acid.
These formulations are NOT considered to be bioequivalent, which means they do not work the same way in the body. Because of this, they are not interchangeable, and if your doctor has prescribed “diclofenac potassium”, for example, it can NOT be substituted with “diclofenac sodium”, even if the dosage is the same, unless your doctor specifically says that it is okay.
Oral diclofenac formulations and dosages
Your doctor may prescribe one of several different types of formulations of oral diclofenac. The preparations available on the market today include tablets, capsules and oral solution packets. In turn, the tablets may have different properties depending on how they are supposed to release the drug into your system. Diclofenac tablets may be:
- Immediate release
The liquid capsules and oral solution packets are usually used as a type of immediate release delivery for diclofenac.
Different formulations of diclofenac are available in different dosages. Your doctor will prescribe the one that they think is best for your case.
Diclofenac sodium: 18 mg, 25 mg, 35 mg, 50 mg, 75 mg, 100 mg
Diclofenac potassium: 25 mg, 50 mg
Oral solution packets: 50 mg
Note that diclofenac oral solution packets are usually only prescribed to patients who suffer from migraine attacks. The medicine should only be used once a migraine headache attack has started. It is not effective as a prophylactic treatment (i.e. preventing migraines) and not indicated for the treatment of some other types of headache, such as cluster headaches.
Topical applications of diclofenac
Diclofenac is sometimes prescribed as a topical treatment to relieve pain associated with osteoarthritis, rheumatoid arthritis, and occasionally skin conditions like actinic keratosis. It is available as a gel or liquid, which is applied topically to the affected area or areas according to your doctor’s instructions.
Topical diclofenac gel: 1%, 3% gel
Topical diclofenac liquid: 1.5%, 2%
Both topical forms of this pain reliever should be applied to clean, dry, healthy skin. After application, the area should not be covered with any bandages, and you will need to wait before covering with clothing or gloves and before bathing, according to your doctor’s instructions. Usually, you can put clothing on the treated area after about 10 minutes, and bathe after approximately one hour.
To help you apply the correct amount of diclofenac gel, the medicine may come with a plastic card marked with lines. This is called a dosing card. You will usually squeeze the gel directly onto this card to measure out the dose prescribed by your doctor. The card should be washed and dried after each use.
The liquid version of diclofenac is measured using a dropper or a pump. Your doctor will tell you how many drops or pumps to apply to the treatment area.
In both cases, you should use your hands to rub the medication over the treatment area evenly. You should wash your hands thoroughly after you finish applying topical diclofenac unless you are treating your hands, in which case you should follow your doctor’s instructions about bathing or showering (usually, wait at least one hour before washing).
Intravenous (IV) diclofenac treatment
This NSAID medication may occasionally be given intravenously (i.e. through an IV line) in a hospital or clinical setting. However, this delivery method of diclofenac is rarely used in a home setting and almost never administered by the patients themselves.
The standard adult dosage for IV diclofenac is 37.5 mg/mL over 15 seconds every 6 hours as needed for pain. Depending on the circumstances of your hospitalization, your doctor may adjust this dose up or down as they see fit. For example, a patient with liver disease is sometimes given a lower dose of intravenous diclofenac.
Generally, the maximum adult dose for IV diclofenac, as well as some oral preparations, is 150 mg per day. Nonetheless, you should not exceed the dosage prescribed to you by your doctor even if it falls below this maximum.
As always, it is extremely important to follow your doctor’s instructions for taking diclofenac sodium, diclofenac potassium, or whichever formulation you have been prescribed. This article is for educational purposes only, and is meant to illustrate that you should not substitute one type of diclofenac for another one, because they may not be equivalent. Using the wrong type of diclofenac can be ineffective at relieving your pain and may cause dangerous side effects.
Remember, the information on this website is for informational purposes only, and is not a substitute for professional medical advice.