이소트레티노인

합성 레티노이드

**이소트레티노인(Isotretinoin)**은 주로 수의 피부과에서 심각한 각화 장애 및 피지선 이상을 관리하는 데 사용되는 1세대 합성 레티노이드입니다. **주요 임상 적용:** * **개의 층판상 이크티오시스(비늘증)** * **피부 T세포 림프종** (상피지향성 림프종) * **피내 각화 상피종** * **다발성 표피 봉입 낭종** * **슈나우저 면포 증후군** * **피지선염** (특히 스탠다드 푸들 및 비즐라) * **고양이 여드름** > **임상 요점:** 피지선에 미치는 강력한 효과 때문에 이소트레티노인은 피지선염 및 슈나우저 면포 증후군 치료에 우선적으로 고려되는 레티노이드이며, 원발성 각화 결함에는 다른 레티노이드(예: 아시트레틴)가 선호될 수 있습니다. 인간에게 심각한 기형 유발 위험(FDA 임부 금기 등급 X)이 있으므로, 수의학적 목적으로 이 약물을 구하는 것은 제조사 및 유통업체에 의해 엄격히 제한될 수 있습니다.

작용 기전: Isotretinoin acts by regulating epithelial cell proliferation and differentiation. * **Receptor Binding:** Retinoids enter the cell and bind to intracellular **Retinoic Acid Receptors (RARs)** and **Retinoid X Receptors (RXRs)** → altering gene transcription. * **Sebosuppressive Effect:** It significantly reduces sebaceous gland size and activity → decreasing sebum production. * **Anti-keratinization & Anti-inflammatory:** Normalizes follicular desquamation (preventing comedone formation) and affects monocyte/lymphocyte function, altering cellular immune responses. * **Antimicrobial (Indirect):** By altering the microenvironment of the sebaceous pore (reducing sebum), it indirectly reduces bacterial populations.

동물 종별 용량

Cats

Feline acne · 5 mg/kg PO once daily · PO · q24h
Feline acne · 10 mg per cat once daily PO · PO · q24h
Feline acne · 1-3 mg/kg q12-24h PO · PO · q12-24h
Epitheliotrophic lymphoma, cutaneus lymphoma · 10 mg/cat once daily PO · PO · q24h

Dogs

Sebaceous adenitis when more conservative treatments have failed · 1 mg/kg PO q12h for one month; if improvement is noted reduce dose to 1 mg/kg PO once daily; long-term goal is to treat with either 1 mg/kg PO every other day or 0.5 mg/kg once daily · PO · q12h initially, then q24h or q48h · Long-term
Sebaceous adenitis · 1-3 mg/kg PO once a day to twice daily · PO · q12-24h
Schnauzer comedo syndrome · 1 mg/kg once daily or divided q12h PO · PO · q12-24h
Sebaceous adenitis in poodles; granulomatous sebaceous adenitis in viszlas · 1-2 mg/kg once daily or divided q12h PO · PO · q12-24h
Epitheliotrophic lymphoma, cutaneus lymphoma · 2 mg/kg once daily or divided q12h PO · PO · q12-24h
Schnauzer comedo syndrome, sebaceous adenitis in poodles, ichthyosis, keratocanthoma, epitheliotropic lymphoma, and sebaceous gland hyperplasia and adenoma · 1-3 mg/kg q12-24h PO · PO · q12-24h

투여 경로

금기

Pregnancy (absolute contraindication - known teratogen)
Nursing mothers
Hypertriglyceridemia
Severe renal disease
Severe hepatic disease
Known hypersensitivity to isotretinoin

이상반응

Dogs: Keratoconjunctivitis sicca (KCS) - most common
Dogs: GI effects (anorexia, vomiting, diarrhea, abdominal distention)
Dogs: CNS effects (lassitude, hyperactivity, behavioral changes, collapse)
Dogs: Stiffness of limbs
Dogs: Pruritus, exfoliative dermatitis, erythema of feet and mucocutaneous junctions/cheilitis
Dogs: Polydipsia, swollen tongue
Cats: Blepharospasm, periocular crusting, erythema
Cats: Diarrhea
Cats: Weight loss secondary to anorexia

약물 상호작용

Vitamin A or other retinoids (etretinate, tretinoin) · May cause additive toxic effects.
Cyclosporine · Isotretinoin may increase cyclosporine levels.
Tetracyclines · Use with tetracyclines may increase the potential for the occurrence of pseudotumor cerebri (cerebral edema and increased CSF pressure).

모니터링

Clinical efficacy
Liver function tests (baseline and if signs appear)
Serum triglycerides and cholesterol
Dogs: Schirmer Tear tests (monthly, especially in older dogs to monitor for KCS)
Cats: Body weight (monitor for anorexia-induced weight loss)

과용량

In a review of 147 exposures reported to the ASPCA APCC (140 dogs, 7 cats), only 5 dogs showed clinical signs, most commonly **hypersalivation**. Cats showed no clinical signs. Because of the drug's potential adverse effects, **gut emptying** should be considered with acute overdoses when warranted. Monitor for GI upset and CNS signs.

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