Introduction
Despite the actually good tolerability of the active ingredient Diclofenac, some side effects may occur, especially with prolonged use. The intake of a high dose also plays a role here. The higher the dose of Diclofenac and the more frequently it is taken, the higher the risk of an occurring side effect.
Effects on the gastrointestinal tract
Probably the best known side effect of Diclofenac is an undesirable effect on the gastrointestinal tract. The reason for this is that the pharmacological inhibition of the enzyme cyclooxygenase means that the stomach‘s protective mucous membrane is no longer built up as quickly as it should. Gastric acid, on the other hand, is still produced in the usual quantity and thus comes into direct contact with the ever thinner stomach mucosa.
After long use of Diclofenac, it can happen that parts of the stomach wall are completely unprotected and come into direct contact with the corrosive stomach acid. This leads to an ulcer (stomach ulcer), which can be accompanied by severe pain. The most dreaded side effect of using Diclofenac is stomach bleeding, which must be treated immediately, sometimes with intensive care.
Before any treatment with Diclofenac, the patient should always be informed about this side effect and above all asked whether he already had a stomach ulcer or still has one. If this is the case, the use of Diclofenac or other preparations that work by a similar mechanism must be carefully considered and alternative preparations used if necessary. If it is not known whether the patient has a stomach ulcer or not, in case of doubt, consideration should be given to having a gastroscopy before taking solid medication with Diclofenac in order to rule out stomach ulcers or older bleeding in the stomach area and duodenum.
Often there is no bleeding in the stomach, but simple stomach complaints, which are reported as stomach pressure or stomach pain. If the patient expresses this, it may be considered to discontinue Diclofenac and replace it with an alternative preparation, or to add an additional stomach protection tablet to Diclofenac, which should inhibit the stomach acid that is harmful in this case. So-called proton pump inhibitors, such as Pantoprazole, are used here. At the beginning a dosage of 20 mg can be chosen and then it can be seen whether this dosage is sufficient or whether it has to be increased to 40 mg.