리오티로닌 나트륨

갑상선 호르몬

리오티로닌 나트륨은 갑상선 호르몬의 활성 세포 형태인 **T3(트리요오드티로닌)**의 합성 형태입니다. 레보티록신(T4)이 갑상선 기능 저하증의 표준 1차 치료제이지만, 리오티로닌은 T4 보충에 반응하지 않는 특정 환축을 위해 보류됩니다. 이러한 무반응은 위장관의 T4 흡수 장애 또는 이론적으로 탈요오드화 효소를 통한 T4에서 T3로의 말초 전환 결함 때문일 수 있습니다. **임상 요점:** * 리오티로닌은 레보티록신에 비해 **작용 시간과 반감기가 훨씬 짧아** 더 자주 투여해야 합니다(보통 하루 3회). * 혈청 T3 농도만 정상화하고 T4 수치는 낮게 유지하여 정상적인 시상하부-뇌하수체-갑상선 피드백 축을 방해하므로 **초기 치료용으로는 권장되지 않습니다**. * 신체의 자연적인 조절 전환 단계(T4 → T3)를 우회하기 때문에 의인성 갑상선 중독증의 위험이 더 높습니다.

작용 기전: Thyroid hormones act primarily at the cellular level to regulate metabolism. * **Mechanism:** T3 enters the cell and binds to **nuclear thyroid hormone receptors (TRs)** → the receptor-hormone complex binds to DNA → stimulates or inhibits the transcription of specific mRNA → alters protein synthesis. * **Physiologic Effects:** Increases the metabolic rate of tissues, enhances oxygen consumption, increases body temperature, stimulates gluconeogenesis, and promotes the mobilization and utilization of glycogen stores. * **Cardiovascular Effects:** Increases heart rate, cardiac output, and blood volume by upregulating beta-adrenergic receptors. * **Development:** Crucial for the adequate development of the central nervous system and skeletal growth.

동물 종별 용량

Cats

Hypothyroidism · 4.4 micrograms/kg PO 2-3 times a day · PO · q8h-q12h
T3 suppression test (diagnostic for hyperthyroidism) · 25 μg · PO · q8h · 7 doses total · Administer 7 doses, then measure T4 and T3 on the morning of the 3rd day, 2-4 hours after the 7th dose.

Dogs

Hypothyroidism (unresponsive to T4) · 4-6 micrograms/kg PO q8h · PO · q8h · Some dogs may require less frequent dosing. Only indicated when T4 supplementation has failed.
Hypothyroidism (refractory to T4) · 4-6 μg/kg · PO · q8h · Not recommended as first-line therapy due to short half-life.

용량은 면허 수의 전문가를 위한 임상 참고 자료입니다. 항상 최신 라벨과 개별 환자에 대해 확인하십시오.

투여 경로

POIV

금기

Acute myocardial infarction
Thyrotoxicosis
Untreated adrenal insufficiency
Untreated adrenal insufficiency (Addison's disease)

이상반응

Tachycardia
Polyphagia
Polyuria/Polydipsia (PU/PD)
Excitability
Nervousness
Excessive panting
Apathy or listlessness (seen in about 10% of cats)
PU/PD (Polyuria/Polydipsia)
Nervousness/Anxiety
Panting
Weight loss

약물 상호작용

Tricyclic/Tetracyclic Antidepressants · Increased risk for CNS stimulation and cardiac arrhythmias.
Antidiabetic Agents (insulin, oral agents) · Thyroid hormones may increase the requirements for insulin or oral antidiabetic agents.
Cholestyramine · May reduce liothyronine absorption; separate doses by at least 4 hours.
Sympathomimetic Agents (epinephrine, norepinephrine) · Thyroid hormones can potentiate the cardiovascular effects of sympathomimetics.
Warfarin · Thyroid hormones increase the catabolism of vitamin K-dependent clotting factors, potentially increasing anticoagulation effects.
Digoxin · Potential for reduced digoxin levels and decreased therapeutic effect.
Ketamine · Concurrent use may cause tachycardia and hypertension. · moderate
Sympathomimetics · Increased risk of cardiac arrhythmias and coronary insufficiency · moderate
Insulin · May alter glucose control, requiring dosage adjustments · minor

모니터링

Serum T3 levels (draw just prior to dosing and 2-4 hours post-pill)
Clinical signs of hyperthyroidism/thyrotoxicosis
Note: Serum T4 levels will remain low during therapy
Serum T3 levels
Clinical signs of hyperthyroidism
Heart rate and rhythm

과용량

**Chronic Overdosage:** Produces signs of iatrogenic hyperthyroidism, including tachycardia, polyphagia, PU/PD, excitability, nervousness, and excessive panting. Some cats (approx. 10%) may exhibit 'apathetic' hyperthyroidism (listlessness, anorexia). **Treatment:** Reduce dosage or temporarily withhold until signs subside. **Acute Massive Overdosage:** Can produce signs resembling a **thyroid storm**. * **Treatment:** If oral ingestion is recent, reduce absorption using standard protocols (emetics, gastric lavage, activated charcoal, cathartics) unless contraindicated by the patient's clinical status. * **Supportive Care:** Oxygen, artificial ventilation, beta-blockers (e.g., propranolol) for tachycardia/arrhythmias, IV fluids, dextrose, and antipyretic agents as needed.

VetSheet 약물 레퍼런스는 면허 수의 전문가를 위한 임상 의사결정 보조 도구이며, 전문적 판단이나 제조사의 최신 라벨을 대신하지 않습니다.