Physiological changes in a woman’s body during pregnancy can change how quickly a medicine is distributed and eliminated from her body. This can affect plasma drug levels and how well a medicine works. Understanding how and when these changes occur can be used to support possible dose adjustments for women who need to use medicines during pregnancy.
Plasma drug levels depend on how quickly a medicine moves into, within (distribution) and leaves (elimination) the body. Pharmacokinetics (PK) is the study of the drug movement (pharma + kinetics) in the body. Pharmacokinetic data from different stages of pregnancy can be used to support possible dose adjustments to maintain optimal plasma levels for maternal health.
The MHRA one-day course has been designed for clinicians (obstetricians, obstetric physicians, other specialists etc) who treat women needing to take medication during pregnancy and academic clinicians interested in studying medicines used during pregnancy. The course aims to increase their general knowledge of PK, how PK of individual medicines can change during pregnancy and of different study design options for measuring medicinal drug levels in pregnant women. The course also aims to raise awareness of the potential of PK modelling to fill gaps in clinical data and encourage PK studies in pregnant women who are already taking medicines.
Report of MHRA/Gates Foundation training Day
The inaugural training event was held in January at the MHRA offices in London. The event was sponsored by the Bill & Melinda Gates Foundation (Gates Foundation), enabling participants to attend free of charge.
The event was attended by Ping Zhao and Doug McNair from the Gates Foundation. Participants came from across the NHS and included obstetricians, consultants in obstetrics and maternal fetal medicine, endocrinology and diabetes, allergy, HIV, and nephrology, specialists in therapeutic monitoring, developmental biology, clinical pharmacologists and academic researchers.
The introductory presentations (June Raine, MHRA Interim Chief Executive and Doug McNair, Gates Foundation) highlighted the pressing need for information to support the proper use of medicines during pregnancy. This was followed by an overview (Carol Postlethwaite, East Surrey Hospital) of the physiological changes including changes in cardiac output, renal clearance, and hepatic enzyme levels which occur in women during pregnancy. Next came presentations (MHRA PK assessors) on PK principles, methodology and key considerations for measuring plasma levels of medicines, followed by examples of how the PK and the dose-exposure-response relationship can be affected by the physiological changes during pregnancy. Participants had an opportunity to reinforce their learning through hands on exercises looking at exposure levels, elimination rates and how these and other PK parameters can be affected during pregnancy.
Later, the use of modelling and simulation approaches in the investigation of PK during pregnancy was discussed. The ongoing MHRA project on Physiologically based Pharmacokinetic modelling (PBPK) of medicines in pregnancy (see our press release) was introduced. Closing remarks (Lucy Chappell, King’s College London) highlighted the importance of better informed use of medicines during pregnancy and emphasised the need for an integrated collaboration across all stakeholders.
Feedback from the course
'Excellent coverage, from introductory surveying unmet needs, background of review – to more detailed/intermediate PK'
'Didn’t realise about modelling programs at all'
'Good introduction to this topic, I definitely feel more educated on it'
'Liked the interactive examples with real life data.'
'This workshop established a nice balance for this diverse group of workshop participants – enabling all to “keep up” and no one feel left behind! Brilliant!'
We would like to thank all those who attended this event, who contributed to make this a very interactive discussion and who provided feedback for future improvements. We hope to see you again at future events.
Please email pk.pregnancy.workshop@mhra.gov.uk if you are interested in attending