医薬品リファレンス

Rifaximin

Rifaximin is a medicine in the class anti bacterial. It is used for hepatic encephalopathy.

薬効分類: Anti Bacterial
効能・効果: hepatic encephalopathy

最終更新日 13 10月 2026

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このページの臨床コンテンツは英語でのみ提供されています。

要点

薬効分類: Anti Bacterial
一般的な剤形: 錠剤
一般的な規格: 200 mg, 550 mg
既知の相互作用: 55 (重大: 2 · 中等度: 15 · 軽度: 38)
商品名: 26
国・市場: 4

剤形、規格、商品名は国によって異なります。お手元の製品をご確認ください。

何に使われるか

作用のしくみ

Antimicrobial action is a result of binding to the beta-subunit of bacterial DNA-dependent RNA polymerase, resulting in inhibition of transcription, Hepatic encephalopathy: Inhibits growth of enteric ammonia-producing bacteria to indirectly reduce serum ammonia level

成人の通常用量（添付文書の要約）

Traveler's Diarrhea: 200 mg PO q8hr for 3 days

添付文書の最初の用法・用量の行のみの要約です。用法・用量の全項目はアプリでご覧いただけます。

妊娠と授乳

妊娠: Unknown Very little is absorbed from the gut, but in animals it caused birth defects (eye, face, heart, spine), some at doses near human exposure. No human data. EU label: not recommended in pregnancy as a precaution.
授乳: Unknown Not known if it passes into milk; poorly absorbed, so unlikely to reach the infant. LactMed: no published experience, so another drug may be preferred, especially with a newborn or preterm infant. EU label: decide whether to stop breastfeeding or the drug.

報告されている副作用

Headache
Nausea
Constipation
Abdominal pain
Flatulence
Rectal tenesmus

禁忌

Hypersensitivity to rifamycin antibiotics

注意が必要な方

Possibility of pseudomembranous colitis
Monitor patients with severe hepatic impairment for increased systemic exposure
Coadministration of cyclosporine with rifaximin resulted in 83-fold and 124-fold increases in rifaximin mean Cmax and AUC in healthy subjects

妊娠中または授乳中であること、腎臓や肝臓の病気、アレルギー、ほかに使用しているすべての薬やサプリメントについて、薬剤師または医師にお伝えください。

主な相互作用 (55)

Cholera vaccine + Rifaximin Major
Microbiota + Rifaximin Major
Amiodarone + Rifaximin Moderate
Bcg intravesical live + Rifaximin Moderate
Cyclosporin + Rifaximin Moderate
Cyclosporine + Rifaximin Moderate
Dronedarone + Rifaximin Moderate
Itraconazole + Rifaximin Moderate
Ketoconazole + Rifaximin Moderate
Lasmiditan + Rifaximin Moderate

All 55 interactions, with severity and what to do

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、Rifaximinの完全なモノグラフ（用量、妊娠・授乳、副作用、警告、すべての相互作用）を表示できます。

Dosing by age, kidney and liver function, and further dose lines
Renal and hepatic dose adjustments
Paediatric dosing
Pharmacokinetics
Patient counselling points
Food interactions

無料アカウントを作成ログイン

WebでPro+を7日間無料でお試し。カード登録不要。

よくある質問

What is Rifaximin used for?

Rifaximin is a medicine in the class anti bacterial. It is used for Hepatic encephalopathy, Irritable bowel syndrome, Traveler's diarrhea.

What side effects have been reported with Rifaximin?

Headache, Nausea, Constipation, Abdominal pain, Flatulence, Rectal tenesmus.

Can Rifaximin be taken in pregnancy or while breastfeeding?

Pregnancy: Unknown. Very little is absorbed from the gut, but in animals it caused birth defects (eye, face, heart, spine), some at doses near human exposure. No human data. EU label: not recommended in pregnancy as a precaution. Breastfeeding: Unknown. Not known if it passes into milk; poorly absorbed, so unlikely to reach the infant. LactMed: no published experience, so another drug may be preferred, especially with a newborn or preterm infant. EU label: decide whether to stop breastfeeding or the drug.

What does Rifaximin interact with?

MediHelp lists 55 known interactions for Rifaximin. Major: 2 · Moderate: 15 · Minor: 38. The most serious include Cholera vaccine, Microbiota, Amiodarone.

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。

ダウンロード：App Store 入手：Google Play

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