Diclofenac and naproxen are two types of medications that belong to a classification of drugs known as non-steroidal anti-inflammatory drugs (NSAIDs). Drugs that belong to the NSAID category are typically used for relieving pain caused by inflammation. They are thought to work by blocking certain prostaglandins, chemicals naturally produced by the body that cause inflammation. Although diclofenac and naproxen belong to the same drug classification and have many factors in common, they have differences that prevent them from necessarily being used interchangeably.

One difference between diclofenac and naproxen is the availability. The most potent versions of both of these drugs are generally available by prescription only. Although it may vary depending on the specific country and its guidelines, a reduced strength version of naproxen may be available over-the-counter to be used for pain relief to reduce tenderness and swelling, while diclofenac is generally a prescription only medication.

Both of the drugs may be recommended for the treatment of pain caused by conditions, such as arthritis, in which the joints become inflamed, bursitis, in which the fluid sac near the shoulder joint is inflamed, and tendinitis, a condition that causes inflammation of the connective tissues of the bone and muscle. Other miscellaneous pain, such as from menstrual cramps, may also be treated with either of the medications. A key variation between diclofenac and naproxen is that naproxen may be more likely than diclofenac to be recommended for the treatment of juvenile inflammatory conditions.

The specific forms in which the medications may be available is also another difference between diclofenac and naproxen. Both of the medications are generally produced in forms to be taken orally. Tablets tend to be the most commonly prescribed form for both medications, but a liquid solution may also be available. In addition to the more widely prescribed tablet and liquid varieties, diclofenac is also produced as a powder that is to be mixed with liquid and swallowed as a form of treatment for migraine headaches. While the tablet and liquid forms of these medications are usually advised to be consumed with food, diclofenac powder is considered to be more effective at relieving the pain of migraine headaches if it is taken on an empty stomach.

If used in in higher dosages than prescribed, diclofenac and naproxen may cause holes, ulcers, and bleeding of the stomach and intestines. Although the medications are similar, it is generally advised to only use one of them at any particular time. Combining the two medications may cause the body to absorb an unsafe amount of the drugs’ active ingredients and cause damage to the stomach and intestines. Signs of stomach or intestinal holes, ulcers, or bleeding include severe abdominal pain, heartburn, or vomit or stool that is dark red or brown. If these symptoms are present, it is typically advised to stop taking the medications and seek medical attention to prevent serious complications.