이미프라민

삼환계 항우울제 (TCA)

이미프라민은 수의학에서 허가 외(off-label)로 사용되는 **삼환계 항우울제(TCA)**입니다. 주로 분리 불안과 같은 행동 문제에 사용되는 것으로 알려져 있지만, 독특한 수용체 프로파일 덕분에 활용도가 매우 높습니다. * **개와 고양이**에서는 **요실금**과 **탈력발작(cataplexy)** 치료에 자주 사용됩니다. * **말**에서는 **기면증(narcolepsy)** 관리 및 약물 유도 사정에 사용됩니다. > **임상 팁:** 이미프라민은 3급 아민 TCA로, 간에서 활성 2급 아민 대사산물인 **데시프라민(desipramine)**으로 빠르게 대사됩니다. 이러한 이중 작용은 세로토닌과 노르에피네프린 경로 모두에 영향을 미쳐 약리학적 작용 범위를 넓혀줍니다.

작용 기전: Imipramine and its active metabolite, desipramine, exert their effects through a complex, multi-receptor pharmacologic profile: * **Monoamine Reuptake Inhibition**: Blocks the presynaptic amine pump, preventing the reuptake of **serotonin (5-HT)** and **norepinephrine (NE)** → increases neurotransmitter concentrations in the synaptic cleft → modulates mood, arousal, and pain pathways. * **Anticholinergic Activity**: Antagonizes **muscarinic receptors** centrally and peripherally. This mechanism is primarily responsible for its efficacy in treating urinary incontinence (facilitating urine storage by relaxing the detrusor muscle) and its common side effects (dry mouth, tachycardia). * **Alpha-Adrenergic Agonism/Antagonism**: Exhibits complex interactions at alpha receptors, which may contribute to increasing internal urethral sphincter tone. * **Antihistaminic (H1) Activity**: Contributes to its significant **sedative** properties.

동물 종별 용량

Cats

Urethral incompetence · 2.5-5 mg (total dose) · PO · q12h
Adjunctive cancer pain treatment · 2.5-5 mg (total dose) · PO · q12h
Anxiety, inappropriate urination · 0.5-1 mg/kg · PO · q12-24h

Horses

Pharmacologic induced ejaculation · 2 mg/kg · IV · once · If imipramine alone does not induce erection and ejaculation in 10-15 minutes, give xylazine 0.2-0.3 mg/kg IV. (Note: ARCI UCGFS Class 2 Drug)
Narcolepsy/cataplexy · 0.55 mg/kg IV or 250-750 mg (total dose) orally · IV, PO · once · PO administration produces inconsistent results.

Dogs

Urethral incompetence · 5-15 mg (total dose) · PO · q12h
Urinary incontinence when other agents fail · 5-20 mg (total dose) · PO · q12h
Cataplexy · 0.5-1 mg/kg · PO · q8h · Titrate dose based on clinical effect
Adjunctive treatment of separation anxiety or other tricyclic antidepressant-responsive behavior disorders · 2.2-4.4 mg/kg · PO · once to twice daily
Adjunctive cancer pain treatment · 0.5-1 mg/kg · PO · q8h

투여 경로

POIV

금기

Prior sensitivity to any tricyclic antidepressant
Concomitant use with monoamine oxidase inhibitors (MAOIs) within 14 days
Glaucoma
History of seizures
Urinary retention
Severe liver disease
Hypersensitivity to tricyclic antidepressants

이상반응

Sedation
Dry mouth
Constipation
Tachycardia
Hyperexcitability
Tremors
Seizures (CNS stimulation)
Bone marrow suppression
Diarrhea
Vomiting
Diarrhoea
Excitability
Arrhythmias
Hypotension
Syncope
Increased appetite

약물 상호작용

Anticholinergic agents · Additive anticholinergic effects; use cautiously
Cimetidine · May inhibit tricyclic antidepressant metabolism and increase the risk of toxicity · major
CNS Depressants · Additive CNS depressant effects; use cautiously
Levodopa · Imipramine may decrease levodopa oral absorption
Phenobarbital · May decrease tricyclic levels
Quinidine · Increased risk for QTc interval prolongation and tricyclic adverse effects
Rifampin · May decrease tricyclic blood levels
SSRIs (e.g., fluoxetine, paroxetine, sertraline) · Increased risk for serotonin syndrome
Sympathomimetic agents · May increase the risk of cardiac effects (arrhythmias, hypertension, hyperpyrexia)
Monoamine Oxidase Inhibitors (including amitraz, selegiline) · Concomitant use (within 14 days) is generally contraindicated due to risk of serotonin syndrome
Thyroid agents · May increase risk for cardiac arrhythmias
Cisapride · Increased risk for prolonged QT interval
Clonidine · Tricyclics may increase blood pressure

모니터링

Clinical efficacy
Adverse effects
ECG (Tricyclics can widen QRS complexes, prolong PR intervals, and invert or flatten T-waves)
Blood Glucose (Tricyclics may increase or decrease blood glucose levels)
Heart rate and rhythm (ECG) in susceptible patients
Signs of serotonin syndrome (agitation, tremors, hyperthermia, tachycardia) if used with other serotonergic drugs
Liver function tests (baseline and periodic)

과용량

Overdosage with tricyclics can be **life-threatening**, leading to severe arrhythmias and cardiorespiratory collapse. Because the toxicities and therapies for treatment are complicated and controversial, it is highly recommended to **contact a poison control center** for further information in any potential overdose situation.

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