Overstappen op een generiek geneesmiddel

Ramp of zegen?
Klinische les
Chiel F. Ebbelaar, Huub A. Lammers en A.F.A.M. (Fred) Schobben

Switching to a generic drugA blessing or a curse?

This supplementary information is presented as submitted by the corresponding author. It has not been copy-edited by NTvG.


Patients often complain when they get a refill of their drugs looking differently. Sometimes these changes have unpleasant consequences. Is this a serious problem or merely fear?

Case description

A patient suffering from Zollinger-Ellison is being treated with Nexium®. After loss of patent only generic omeprazol will be reimbursed. The treating specialist insists on the originator drug. After a long discussion generic tablets and capsules are tried without success. Also pantoprazol and rabeprazol do not help. Finally the pharmacist dispenses Nexium® again, at his own expense.

A man suffering from epilepsy uses Keppra® for many years. At the introduction of a generic there is a local agreement that switching is acceptable. When the patient is confronted with the switch he turns very angry and forces the pharmacy to solve the problem: he only wants Keppra®. As there is no intolerance for components of the generic the originator is not being reimbursed.


A change of Dutch law in 2005 permitted the health insurance companies to assign one brand of each active substance to be reimbursed. By negotiating low prices for their preferred drugs much money has been saved at the cost of a lot of resistance and inconvenience.

Generic drugs registered in Europe have shown to be bioequivalent with the originator drug. The confidence interval of the difference of the amount of both drugs reaching the systemic circulation must be between 80 and 125%. This means that the real difference is much smaller. When two batches of the originator are being compared the same requirements are valid. There is a lot of negative publicity on generic drugs; this information often originates from the innovator companies. Meta-analyses on outcome comparison support generic substitution.

The problems described when switching form originator drug to generic (or between two generics) are partially explained by the loss of trust to the treatment. The different appearances also cause a lot of confusion, leading to incorrect drug intake. Local acting products cannot be compared on the basis of bioequivalence. For biotechnological drugs full identity could not be proven by analytical techniques. Nevertheless these products can be switched, but extra monitoring is required.


Generic drugs are mostly equivalent to their originator drug, and switching is allowed. Care should be taken for patients with specific allergies. Unwanted effects of drugs are frequently seen, but when they occur after a product switch they are ascribed to the change. After a switch between two batches of the originator drug nobody will accuse the drug although the difference is identical.

In order not to risk loss of patients trust in their treatment and therapists and to prevent disquiet it is desirable to stick to the same product as far as possible. For switching good education and patient information is essential.