아미트리프틸린

삼환계 항우울제 (TCA) / 행동 조절제 / 신경병증성 통증 조절제

아미트리프틸린은 1세대 **삼환계 항우울제(TCA)**입니다. 반려견의 일차적 행동 장애(예: 분리 불안) 치료에 있어서는 클로미프라민이나 SSRI(예: 플루옥세틴)와 같은 최신 약물로 대체되는 추세이지만, 수의학에서는 여전히 다방면으로 활용되는 약물입니다. **임상 팁**: 이 약물의 다중 수용체 활성은 **신경병증성 통증**, **소양증**(강력한 항히스타민 효과), 그리고 **고양이 특발성 하부 요로 질환(FLUTD/FIC)**의 보조 치료에 특히 유용하게 만듭니다. 조류의 깃털 뽑기 행동을 조절하기 위해 사용되기도 합니다.

작용 기전: Amitriptyline and its active metabolite, **nortriptyline**, exhibit a complex pharmacologic profile, affecting multiple receptor systems: * **Serotonin (SERT) & Norepinephrine (NET) Reuptake Inhibition**: Blocks the amine pump → increases synaptic levels of 5-HT and NE → mood stabilization and descending pain pathway modulation. * **H1-Receptor Antagonism**: Potent antihistamine effect → stabilizes mast cells and provides antipruritic action. * **M1-Muscarinic (Anticholinergic) Antagonism**: Causes smooth muscle relaxation (useful in FLUTD) but also leads to side effects like dry mouth and urine retention. * **Alpha-1 Adrenergic Antagonism**: Can cause mild vasodilation and sedation. * **NMDA Receptor & Sodium Channel Blockade**: Contributes to its efficacy in treating chronic, neuropathic pain.

동물 종별 용량

Dogs

Adjunctive treatment of pruritus · 1-2 mg/kg PO q12h · PO · q12h
Acral pruritic dermatitis · 2.2 mg/kg PO twice daily · PO · q12h · 2-4 week trial recommended · Only occasionally effective.
Separation anxiety or generalized anxiety · 1-2 mg/kg PO q12h · PO · q12h · Use with behavior modification.
Behavior disorders amenable to tricyclics · 1-4 mg/kg PO q12h. Begin at 1-2 mg/kg PO q12h for 2 weeks, increase by 1 mg/kg up to maximum dosage (4 mg/kg) as necessary. If no clinical response, decrease by 1 mg/kg PO q12h for 2 weeks until at initial dosage. · PO · q12h
Behavior disorders amenable to tricyclics · 2.2-4.4 mg/kg PO q12h · PO · q12h
Behavior disorders amenable to tricyclics · 0.25-1.5 mg/kg PO every 12-24h · PO · q12-24h
Neuropathic pain · 1-2 mg/kg PO q12-24h · PO · q12-24h
Adjunctive treatment of pain associated with appendicular osteosarcoma · 1-2 mg/kg PO q12-24h · PO · q12-24h
Management of chronic anxiety, compulsive disorders, and separation anxiety · 1-2 mg/kg · PO · q12-24h · Clomipramine is an authorized preparation for dogs and is claimed to have better anticompulsive properties.

Birds

Adjunctive treatment of feather plucking · 1-2 mg/kg PO q12-24 hours. Anecdotal reports indicate some usefulness. Barring side-effects, may be worth a more prolonged course of therapy to determine efficacy. · PO · q12-24h · Prolonged course

투여 경로

POParenteral

금기

Prior sensitivity to any tricyclic antidepressant
Concomitant use with monoamine oxidase inhibitors (MAOIs)

이상반응

Sedation
Constipation
Urinary retention
Hyperexcitability (dogs)
Seizures (rare)
Cardiac dysrhythmias
Bone marrow suppression
Vomiting
Diarrhea
Hypersalivation (cats)
Anorexia (cats)
Thrombocytopenia
Neutropenia
Unkempt hair coat (cats)
Ataxia
Disorientation

약물 상호작용

Anticholinergic agents · Increased effects; hyperthermia and ileus possible
Cimetidine · May inhibit tricyclic antidepressant metabolism and increase the risk of toxicity · moderate
Cisapride · May have additive effects on QTc interval; possible serious arrhythmias may result
Monoamine Oxidase Inhibitors (selegiline, amitraz) · Potential life-threatening serotonin syndrome; use together not recommended
CNS Depressants · Increased sedative effects
Diazepam · Possible increased amitriptyline levels · moderate
Quinidine · Increased risk for QTc interval prolongation and tricyclic adverse effects
Selective-Serotonin Re-uptake Inhibitors (SSRIs, fluoxetine) · Potential increased amitriptyline levels, increased risk for serotonin syndrome; enhanced monitoring suggested if used together
Sympathomimetic agents · May increase the risk of cardiac effects (arrhythmias, hypertension, hyperpyrexia)
Thyroid agents · Increased risk for arrhythmias; monitor closely
Monoamine oxidase inhibitors (MAOIs) · Risk of fatal serotonin syndrome. Requires a minimum 2-week washout period. · major
Chlorphenamine · Metabolized by CYP2D6; may alter amitriptyline metabolism. · moderate

모니터링

Clinical efficacy (behavior, pain, or pruritus improvement)
Adverse effects
Baseline cardiac evaluation (ECG) prior to therapy
Baseline CBC and serum chemistry panel prior to therapy
Liver enzymes in cats (prior to therapy, 1 month after initial therapy, and yearly thereafter)

과용량

Overdosage with tricyclics can be **life-threatening** (arrhythmias, cardiorespiratory collapse). Because toxicities and therapies are complicated, it is recommended to contact an animal poison control center immediately in any potential overdose situation. * **Dogs**: Common findings include lethargy and tachycardia. * **Cats**: Common findings include vocalization, ataxia, mydriasis (dilated pupils), tachycardia, disorientation, lethargy, and agitation.

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