The gravity dependence of pharmacodynamics [09.04.19]
Long-lasting manned space missions beyond Earth's orbit, e.g., to Mars are already planned by space agencies and private corporations.1 Then humans will have to live in closed environments under space conditions including microgravity for long periods without immediate access to medical or pharmacological support from Earth. To minimize the risk for astronauts, the effects of relevant drugs under space conditions will have to be investigated in detail before such manned mission will start.
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Original paper
Kohn, Florian P. M.; Hauslage, Jens (2019): The gravity dependence of pharmacodynamics: the integration of lidocaine into membranes in microgravity. In: npj Microgravity 5 (1), S. 5. DOI: 10.1038/s41526-019-0064-5.
Abstract
To realize long-term manned space missions, e.g. to Mars, some important questions about pharmacology under conditions of different gravity will have to be answered to ensure safe usage of pharmaceuticals. Experiments on the International Space Station showed that the pharmacokinetics of drugs are changed in microgravity. On Earth, it is well known that the incorporation of substances into cellular membranes depends on membrane fluidity, therefore the finding that membrane fluidity is gravity dependent possibly has effects on pharmacodynamics of hydrophobic and amphiphilic substances in microgravity. To validate a possible effect of gravity on pharmacodynamics, experiments have been carried out to investigate the incorporation of lidocaine into plain lipid membranes under microgravity conditions. In microgravity, the induced increase in membrane fluidity associated with lidocaine incorporation is smaller compared to 1g controls. This experiment concerning the gravity dependence of pharmacodynamics in real microgravity clearly shows that the incorporation of amphipathic drugs into membranes is changed in microgravity. This might have significant impact on the pharmacology of drugs during long-term space missions and has to be investigated in more detail to be able to assess possible risks.
