News items Launch of a platform with tailored medication doses for pregnant women

25 March 2024

Radboud university medical center, the Dutch Teratology Information Service Lareb and Maastricht UMC+ jointly launch a platform with drug dosing advice for pregnancy. On this platform, they share tailored dose recommendations for pregnant women and their unborn children, based on specific evidence in these groups. Outlining tailored dose recommendations in pregnancy is challenging because scientific evidence is lacking. However, the use of computer models alongside other data can help address this.

This new platform with dose recommendations is designed for medication prescribers and pregnant women. It is the result of a joint initiative from Radboudumc, the Teratology Information Service of the Netherlands Pharmacovigilance Centre Lareb, and Maastricht UMC+. The platform, hosted on the website of the Teratology Information Service Lareb, now features its first dose recommendation, for the antidepressant sertraline. Various dose recommendations for commonly used drugs in pregnancy will be added to the platform in 2024 and the following years.

Three out of four women use medication during pregnancy

Three out of four women use medication during pregnancy. However, most medication leaflets state "do not use during pregnancy". Knowledge about safe and effective treatments during pregnancy is often inadequate because pregnant women are routinely excluded from drug research. However, a woman's body undergoes changes during pregnancy, potentially requiring a different medication dose. An excessive dose may increase the risk of side effects, while an insufficient dose could result in a less effective treatment. Moreover, the amount of medication reaching a baby is not always clear. This is important because excessive or insufficient doses of a drug may have adverse effects on the child's health.

Project leader Saskia de Wildt: ‘Women biologically differ from men. During pregnancy, a woman's body undergoes even more changes. This could be a reason to adjust the standard dose of certain medications. Therefore, it is incredibly important that we gain more knowledge about adequate doses for both the mother and unborn child.’ De Wildt is a pediatrician and professor of Clinical Pharmacology at Radboudumc and medical director of the Dutch Pediatric Formulary, which issues drug dose recommendations for children.

Drug doses investigated in virtual pregnant women

Dose recommendations on the platform are based on a combination of evidence sources. Placental research can help determine whether and how much of a medication administered to a pregnant woman crosses the placenta and reaches her child. This research is conducted at Radboudumc using placentas collected shortly after childbirth with women's informed consent. In addition, computer models or 'virtual pregnant women' can be used to explore if dose adjustments are necessary during pregnancy for both mother and child.

Charlotte Koldeweij, medical doctor and PhD candidate at Radboudumc, explains: ‘We derive drug dose recommendations by integrating model predictions with safety and efficacy data specific to pregnancy. These dose recommendations and underlying evidence are reviewed by a working committee comprising clinicians, a pharmacologist, a medical ethicist, pregnant women and partners. Upon approval, the issued dose recommendations are made available to clinicians and pregnant women through the platform.

Agnes Kant, director of the Dutch Pharmacovigilance Centre Lareb, says: ‘The Dutch Teratology Information Service already includes a lot of information on the safety of drugs used in pregnancy and during lactation. It's really inspiring that this information can now be supplemented with drug dosing advice.’

Liesbeth Scheepers, gynecologist-perinatologist at MUMC+ and associate professor at Maastricht University, declares: ‘Until now, we have been using drug doses that are not evidence-based. For some drugs, we see that adjustments are really necessary. Pregnant women are finally getting the attention they deserve. This is truly an important milestone.’

Advice on use medication during pregnancy does not change

The advice on whether a medicine can be used safely during pregnancy does not change. More information about this can be found on the Dutch Teratology Information Service Lareb website. There are currently no indications that current doses of commonly used drugs during pregnancy are unsafe for the mother or unborn child. For some drugs, the dosage may be optimized to be more effective, without changing the safety of the unborn child. It may even be safer because it improves the mother's health.

An international information resource

The initiators hope that the launch of this platform will pave the way for an international information resource where healthcare providers and pregnant women can find well-substantiated dose recommendations for pregnant women and their unborn children. A summary of the underlying evidence and considerations for recommended drug doses is now available on the MELINDA website. This website also includes information on how computer models can be used to determine suitable drug doses in pregnant women and children.

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Pauline Dekhuijzen

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