相互作用
Estradiol + Fosphenytoin
重症度: 重大
Estradiol and Fosphenytoin: major interaction.
最終更新日
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概要
Phenytoin, the active metabolite of fosphenytoin, is a strong enzyme inducer that increases estradiol clearance and lowers its levels. This can cause loss of efficacy and breakthrough bleeding, and contraceptive failure has been reported with hormonal products.
この相互作用をわかりやすく説明すると
Estradiol and Fosphenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Estradiol belongs to Endocrine; Fosphenytoin belongs to Central Nervous System.
なぜ起こるのか
Induction of CYP3A4 and possibly P-glycoprotein by phenytoin, increasing estradiol metabolism.
対処法
Use a non-hormonal or alternative contraceptive method when contraception is needed. For menopausal therapy, monitor for reduced effect and increase the estradiol dose if required.
薬剤師に尋ねること
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
Pro+会員向け
ページ全体を見る
アカウントを作成してPro+トライアルを始めると、EstradiolとFosphenytoinの臨床対応の詳細なアドバイス、追加の注記、エビデンスの詳細、処方全体を対象とした相互作用チェッカーを利用できます。
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
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Estradiolのその他の相互作用
Fosphenytoinのその他の相互作用
よくある質問
Can I take Estradiol with Fosphenytoin?
MediHelp rates the interaction as major. Estradiol and Fosphenytoin can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Phenytoin, the active metabolite of fosphenytoin, is a strong enzyme inducer that increases estradiol clearance and lowers its levels. This can cause loss of efficacy and breakthrough bleeding, and contraceptive failure has been reported with hormonal products.
How serious is the interaction between Estradiol and Fosphenytoin?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Use a non-hormonal or alternative contraceptive method when contraception is needed. For menopausal therapy, monitor for reduced effect and increase the estradiol dose if required.
What other medicines interact with Estradiol?
MediHelp also lists interactions of Estradiol with, for example, Anastrozole, Fezolinetant, Ospemifene. The full list is on the Estradiol page.
完全なモノグラフ、用量、相互作用チェッカーはMediHelpアプリで
MediHelpアプリで、完全なリファレンスを開き、複数薬剤の相互作用をチェックし、用量ツールを利用できます。
