カルシウム炭酸がレボチロキシン吸収に及ぼす影響
N Singh1, P N Singh, J M Hershman
1Division of Endocrinology and Metabolism, Endocrinology 111D, VA Greater Los Angeles Healthcare System, 11301 Wilshire Blvd, Los Angeles, CA 90073. nsingh@ucla.edu
JAMA
|June 6, 2000
まとめ
炭酸カルシウムはレボチロキシン吸収を大幅に低下させ,患者のチロトロピン濃度が上昇します. この相互作用は,炭酸カルシウムへのレボチロキシン吸収によるもので,甲状腺ホルモン置換療法に影響を与える可能性があります.
科学分野:
- エンドクリノロジー エンドクリノロジー
- 薬理学 薬理学とは
- 薬物相互作用 薬物相互作用
背景:
- カルシウム炭酸とレボチロキシンを同時に使用することは,特に閉経後の女性では一般的です.
- カルシウム炭酸とレボチロキシン吸収の相互作用に関する体系的な研究は欠けている.
- 薬物相互作用の可能性は,共同処方が広く普及しているため,調査を義務付けています.
研究 の 目的:
- レボチロキシン吸収におけるカルシウム炭酸の潜在的干渉を調査する.
- カルシウム炭酸が甲状腺ホルモンレベルに与える影響を評価するために.
- カルシウム炭酸とレボチロキシンとの相互作用のメカニズムを理解するために.
主な方法:
- 安定したレボチロキシン療法を受けている20人の甲状腺機能低下患者を含む前向きなコホート研究.
- 炭酸カルシウムとチロキシン (T4) の結合を評価するためのインビトロ研究.
- 自由T4,総T4,トライヨドチロニン (T3) とチロトロピンの含有量をベースライン,カルシウム炭酸の併用投与中,および中止後に測定する.
主要な成果:
- 炭酸カルシウムは,自由T4と総T4の平均値を大幅に低下させた.
- 炭酸カルシウムの使用中にタイロトロピンの平均濃度が大幅に増加した.
- 実験室内研究では,酸性条件下でのカルシウム炭酸にT4の吸収が示され,生物利用性の低下のメカニズムを示唆しました.
結論:
- 炭酸カルシウムはレボチロキシン吸収を減らし,チロトロピンのレベルを上昇させます.
- 酸性環境でレボチロキシンが炭酸カルシウムに吸収されると,その生物利用性が低下する可能性があります.
- この相互作用は,レボチロキシンと炭酸カルシウムの両方を投与している患者で慎重に検討する必要があります.
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