Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The increased risk of thromboembolism in women using estrogen-containing (OCs) oral contraceptives has been related to decreased (AT3) antithrombin 3 levels of about 10%. A dose-dependent effect on AT3 has been suggested. Using an automated chromogenic technique, we have studied the effect on AT3 of a very high dose of ethinyl estradiol (5 mg daily for 5 days), popularly known as the "morning after pill," which in the Netherlands is prescribed to 45,000 women. The mean decrease in AT3 level in 13 patients of average age 23 was 17% of the pretreatment value (p=0.0013). Values in U/ml as mean + or - 50 were 1.03 + or - 0.12 on day 0, 0.86 + or - 0.12 on day 5, and 0.97 + or - 0.15 on day 12. The day 0 samples were taken immediately before the start of therapy and those on day 12 were taken 1 week after discontinuing therapy. The normal range is 0.80-1.40 U/ml. The effect of this dose was also studied in 2 volunteers. The 1st volunteer did not wish to continue after the first dose of 5 mg ethinyl estradiol because of vomiting. On day 2 AT3 had increased by 22% and on day 4 had decreased by 12% of the pretreatment level. The 2nd volunteer also vomited on day 1, but continued the medication. AT3 increased on day 2 and then fell to 18.5% of pretreatment level on day 4. Changes in AT3 ran parallel with changes in hematocrit (seen in figure). High doses of estrogen have been reported to cause an increase in blood volume of 18% and a decrease in hematocrit of 15%. Plasma volume increases by 11% during OC use. Estrogen induced retention of salt and water causing hemodilution rather than increased consumption or decreased synthesis, may explain the reported decreases in AT3 levels. This does not rule out the possibility that subnormal values contribute to a hypercoagulable state. In 1 of our patients on day 5 of treatment AT3 fell to 0.60 U/ml, which is within the range where thromboembolism may occur in certain settings, such as emergency surgery or a history of thrombosis.
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PMID:"Morning after pill" and antithrombin III. 611 73