Hormones 2016

Ethinylestradiol
Ethinylestradiol is metabolised in the liver. Hydroxylation appears to be the
main metabolic pathway. 60% of a dose is excreted in the urine and 40% in
the faeces. About 30% is excreted in the urine and bile as the glucuronide or
sulphate conjugate (emc, 2016).
It is excreted approximately 60% in the bile and 33% through the kidneys
(drugbank, 2013c).
The rate of metabolism of ethinylestradiol is affected by several factors,
including enzyme- inducing agents, antibiotics and cigarette smoking.
After oral administration, an initial peak occurs in plasma at 2 to 3
hours, with a secondary peak at about 12 hours after dosing; the second
peak is interpreted as evidence for extensive enterohepatic circulation of
ethinylestradiol.
The elimination half-life of ethinylestradiol ranges from 5 to 16 hours (emc,
2016).
Quantitatively, the major metabolic pathway for ethinyl estradiol, both
in rats and in humans, is aromatic hydroxylation, as it is for the natural
oestrogens (drugbank, 2013c)
Typical dosage
Pre-op - 50–150 mcgs/day
Post-op - 50 mcgs/day.
Route
Tablets - Ethinylestradiol.
Contraindications
Active or recent arterial thromboembolic disease, e.g. angina, myocardial
infarction; Current or previous idiopathic venous thromboembolism (deep
venous thrombosis, pulmonary embolism); Acute liver disease or a history
of liver disease as long as liver function tests have failed to return to normal;
porphyria; Known hypersensitivity to the active substance or to any of the
excipients (emc, 2016).
Side-effects
Central Nervous System
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Version 2016.3576– – Document LATEXed – 1st May 2016
[git] • Branch: 1.5 @ 26b5e6d • Release: 1.5 (2016-05-01)