デクスラゾキサン
**デクスラゾキサン**は、主に獣区腫瘍学で使用される細胞内鉄キレート剤および化学防護剤です。 * **心臓保護**：アントラサイクリン系薬（ドキソルビシンなど）に関連する累積的かつ用量依存的な心毒性を軽減するために使用されます。 * **血管外漏出の管理**：ドキソルビシンの誤った血管外投与（漏出）によって引き起こされる重知な組織壞死に対する重要な解毒剤として機能します。 **臨床のポイント**： * 心臓保護には非常に有効ですが、非常に高価であり、多くの飼い主にとって費用がネックになる場合があります。 * デクスラゾキサンががん細胞を部分的に保護し、化学療法の抗腫瘍効果を低下させる可能性があるという理論的懸念と人での証拠があります。
作用機序: Dexrazoxane is a cyclic derivative of EDTA that readily penetrates cell membranes. * Once intracellular, it is **hydrolyzed** into an active ring-opened chelating metabolite. * **Active Metabolite** → **Chelates intracellular iron** → Prevents the formation of the highly reactive **anthracycline-iron complex**. * This prevents the generation of destructive superoxide free radicals → **Protects the myocardium** from oxidative stress and irreversible anthracycline-induced cardiomyopathy. * *Mechanistic Note*: It also acts as a reversible inhibitor of **Topoisomerase II**, which is believed to contribute to its protective effects against severe tissue necrosis during extravasation injuries.
動物種別の用量
- Treatment of anthracycline (doxorubicin, epirubicin, etc.) extravasation · 1000 mg/m2 · IV · within 6 hours and again on day 2. Infuse 500 mg/m2 on day 3 · 3 days · Terminate doxorubicin infusion immediately, and infuse intravenously in a separate infusion. Acute surgical evaluation is performed. Dosage recommendations are for human patients, but may apply to veterinary patients.
- Treatment of anthracycline extravasation · 10 times the doxorubicin dose · IV · within 3 hours and again at 24 and 48 hours after extravasation · 48 hours · Anecdotally; significantly reduces local tissue injury.
- Prevention of doxorubicin-induced cardiomyopathy · 10:1 ratio (e.g., 300 mg/m2 of dexrazoxane to 30 mg/m2 doxorubicin) · IV · starting 30 minutes of, and prior to the doxorubicin dose · Given as slow IV bolus (as a short, IV bolus).
- Prevention of doxorubicin-induced cardiomyopathy · 10:1 ratio (e.g., 300 mg/m2 of dexrazoxane to 30 mg/m2 doxorubicin) · IV · starting 30 minutes before doxorubicin is administered · Given as slow IV bolus. Use can be considered in breeds at risk (Shelties, Collies, Australian Shepherds, etc.), dogs exceeding usual cumulative dose cutoff, and cases with preexisting cardiac disease where no effective chemo options exist.
用量は獣医療従事者向けの臨床リファレンスです。必ず最新の添付文書と個々の患者で確認してください。
投与経路
禁忌
- Should not be used unless an anthracycline antineoplastic agent is being used
- Unknown based on monograph, but generally avoid in patients not receiving anthracyclines
有害事象
- Additive myelosuppression
- Potential reduction in efficacy of anthracycline antitumor agents
- Testicular atrophy (observed in dogs)
- Myelosuppression (documented in humans)
- Decreased clinical efficacy of anthracycline antineoplastic agents
薬物相互作用
- Myelosuppressive agents · Additive myelosuppression may occur when used concurrently.
- Anthracycline antineoplastic agents · May decrease the clinical efficacy of the chemotherapy · moderate
モニタリング
- CBC
- Echocardiogram (if used for cardioprotection)
- ECG (if used for cardioprotection)
- Complete blood count (CBC) for myelosuppression
- Cardiac monitoring (ECG, echocardiogram) if used for cardiotoxicity
- Extravasation site for healing or necrosis
過量投与
Because of the method of administration and drug expense, overdoses are unlikely in veterinary medicine. As there is no known antidote, treatment would be supportive. Potentially, the drug could be removed via hemodialysis.
VetSheet の薬剤リファレンスは、獣医療従事者向けの臨床意思決定支援を目的としており、専門的判断やメーカーの最新添付文書に代わるものではありません。