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J R Soc Med. 1981 June; 74(6): 422–426.
PMCID: PMC1438765

Altered drug binding to serum proteins in pregnant women: therapeutic relevance.


The binding of diazepam, phenytoin and valproic acid to serum proteins in vitro has been compared in pregnant women of different gestational ages and in controls. The unbound fraction of each of three drugs was elevated during pregnancy (particularly during the last 8 weeks) probably due, at least in part, to a fall in serum albumin concentration. These findings may provide a partial explanation for the increase in the clearance of certain drugs during pregnancy and need to be taken into account when interpreting serum drug levels in clinical practice.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.
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  • Piafsky KM. Disease-induced changes in the plasma binding of basic drugs. Clin Pharmacokinet. 1980 May-Jun;5(3):246–262. [PubMed]
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