title: Abnormal serum free thyroid hormone levels due to heparin administration.
abstract: Fractionated or unfractionated heparin may produce artefactual elevation in measured concentrations of free thyroid hormones. Although the specific cause is unknown, it may be a consequence of displacement of thyroid hormones from their binding sites by free fatty acids liberated in vitro. We describe four cases of heparin-induced abnormalities in free thyroid hormone measurements where some diagnostic confusion was generated. Increasing physician awareness of this poorly appreciated entity may avert diagnostic confusion and unnecessary investigation.
authors.affiliation: Department of Medicine, University Hospital of Wales, Cardiff, UK. laji@doctors.org.uk
authors.forename: K
authors.initials: K
authors.lastname: Laji
authors.forename: B
authors.initials: B
authors.lastname: Rhidha
authors.forename: R
authors.initials: R
authors.lastname: John
authors.forename: J
authors.initials: J
authors.lastname: Lazarus
authors.forename: J S
authors.initials: JS
authors.lastname: Davies
mesh_terms: D000328:Adult; D000925:Anticoagulants / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000009:adverse effects*; D006801:Humans; D006981:Hyperthyroxinemia / Q000139:chemically induced*; D008297:Male; D008875:Middle Aged; D013972:Thyrotropin / Q000097:blood / Q000187:drug effects; D014284:Triiodothyronine / Q000097:blood / Q000187:drug effects*
chemical_list: D000925:Anticoagulants; D014284:Triiodothyronine; D013972:Thyrotropin; D006493:Heparin