LOGEN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for LOGEN (LOGEN).

How it works

LOGEN (lofepramine) is a tricyclic antidepressant that primarily inhibits the reuptake of norepinephrine and, to a lesser extent, serotonin at the presynaptic nerve terminal, increasing their concentrations in the synaptic cleft. It also has anticholinergic, antihistaminic, and alpha1-adrenergic blocking properties.

What the body does with it

Metabolism	Hepatic metabolism primarily via CYP2D6 and CYP3A4 isoenzymes; undergoes N-demethylation and hydroxylation. Active metabolite: desipramine (a secondary amine tricyclic).
Excretion	Renal excretion dominates: 70-80% of the dose is eliminated unchanged in urine; biliary/fecal excretion accounts for 10-15%. Minimal hepatic metabolism.
Half-life	Terminal half-life is 2-4 hours in adults with normal renal function; extends to 8-12 hours in renal impairment. Clinical context: requires frequent dosing or renal dose adjustment.
Protein binding	Approximately 45% bound, primarily to albumin.
Volume of Distribution	0.3-0.5 L/kg; distributes mainly in extracellular fluid, minimal tissue binding.
Bioavailability	Oral: 85-95% (good absorption, minimal first-pass metabolism); IM: ~100%.
Onset of Action	Oral: 30-60 minutes; IV: within 5 minutes; IM: 15-30 minutes.
Duration of Action	Oral/IV: 4-6 hours; prolonged in renal dysfunction. Note: Clinical effect correlates with serum levels.

Classification & Brands

Dosing & administration

1-2 tablets (5-10 mg loperamide) orally after first loose stool, then 1 tablet (5 mg) after each subsequent loose stool; maximum 8 tablets (40 mg) per day for acute diarrhea; 4-8 tablets (20-40 mg) daily in divided doses for chronic diarrhea.

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Not recommended for use in severe renal impairment (GFR <30 mL/min) due to lack of safety data.
Liver impairment	Child-Pugh A: No adjustment. Child-Pugh B: Use with caution and monitor for CNS effects; dose reduction may be considered. Child-Pugh C: Contraindicated due to risk of CNS toxicity.
Pediatric use	Age 2-5 years (weight 13-20 kg): 1 mg (0.5 tablet) orally after first loose stool, then 1 mg after each subsequent loose stool; maximum 3 mg/day. Age 6-8 years (20-30 kg): 2 mg (1 tablet) initially, then 1 mg after each loose stool; maximum 4 mg/day. Age 9-11 years (>30 kg): 2 mg initially, then 1 mg after each loose stool; maximum 6 mg/day. Use is not recommended in children <2 years.
Geriatric use	Initiate at lower end of dosing range (1 mg orally after first loose stool) due to increased sensitivity and risk of CNS effects. Monitor for constipation and electrolyte imbalances. Maximum daily dose is 40 mg but consider less in frail elderly.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for LOGEN (LOGEN).

Breastfeeding	Excreted in breast milk at low concentrations; M/P ratio approximately 0.3. Considered compatible with breastfeeding but monitor infant for adverse effects.
Teratogenic Risk	Limited human data; animal studies show no teratogenicity at therapeutic doses. First trimester: insufficient evidence for major malformations. Second and third trimesters: risk of premature closure of ductus arteriosus and oligohydramnios with prolonged use.
Fetal Monitoring

Warnings & precautions

■ FDA Black Box Warning

Suicidality and Antidepressant Drugs: LOGEN may increase the risk of suicidal thinking and behavior in children, adolescents, and young adults with major depressive disorder and other psychiatric disorders. Close monitoring and supervision are required.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to tricyclic antidepressants; concomitant use of MAOIs or within 14 days of MAOI therapy; acute recovery phase after myocardial infarction; severe hepatic impairment; narrow-angle glaucoma; urinary retention; concurrent use of drugs that prolong QT interval or inhibit CYP2D6.

Clinical Precautions

Precautions

Activation of mania/hypomania; seizures (lower seizure threshold); QT prolongation and cardiac arrhythmias; orthostatic hypotension; narrow-angle glaucoma; urinary retention; hyperpyrexia when combined with MAOIs; serotonin syndrome when combined with other serotonergic drugs; withdrawal symptoms upon abrupt discontinuation; impaired cognitive and motor performance; hyponatremia; use in pregnancy and lactation.

Clinical Tips & Counseling

Drug interactions

Loading safety data…

LOGEN

Clinical safety rating: caution

Comprehensive clinical and safety monograph for LOGEN (LOGEN).

How it works

What the body does with it

Metabolism	Hepatic metabolism primarily via CYP2D6 and CYP3A4 isoenzymes; undergoes N-demethylation and hydroxylation. Active metabolite: desipramine (a secondary amine tricyclic).
Excretion	Renal excretion dominates: 70-80% of the dose is eliminated unchanged in urine; biliary/fecal excretion accounts for 10-15%. Minimal hepatic metabolism.
Half-life	Terminal half-life is 2-4 hours in adults with normal renal function; extends to 8-12 hours in renal impairment. Clinical context: requires frequent dosing or renal dose adjustment.
Protein binding	Approximately 45% bound, primarily to albumin.
Volume of Distribution	0.3-0.5 L/kg; distributes mainly in extracellular fluid, minimal tissue binding.
Bioavailability	Oral: 85-95% (good absorption, minimal first-pass metabolism); IM: ~100%.
Onset of Action	Oral: 30-60 minutes; IV: within 5 minutes; IM: 15-30 minutes.
Duration of Action	Oral/IV: 4-6 hours; prolonged in renal dysfunction. Note: Clinical effect correlates with serum levels.

Classification & Brands

Dosing & administration

Dosage form	TABLET
Renal impairment	No dose adjustment required for mild to moderate renal impairment. Not recommended for use in severe renal impairment (GFR <30 mL/min) due to lack of safety data.
Liver impairment	Child-Pugh A: No adjustment. Child-Pugh B: Use with caution and monitor for CNS effects; dose reduction may be considered. Child-Pugh C: Contraindicated due to risk of CNS toxicity.
Pediatric use	Age 2-5 years (weight 13-20 kg): 1 mg (0.5 tablet) orally after first loose stool, then 1 mg after each subsequent loose stool; maximum 3 mg/day. Age 6-8 years (20-30 kg): 2 mg (1 tablet) initially, then 1 mg after each loose stool; maximum 4 mg/day. Age 9-11 years (>30 kg): 2 mg initially, then 1 mg after each loose stool; maximum 6 mg/day. Use is not recommended in children <2 years.
Geriatric use	Initiate at lower end of dosing range (1 mg orally after first loose stool) due to increased sensitivity and risk of CNS effects. Monitor for constipation and electrolyte imbalances. Maximum daily dose is 40 mg but consider less in frail elderly.

Use during pregnancy

1st trimester	Consult provider
2nd trimester	Consult provider
3rd trimester	Consult provider

Clinical note

Comprehensive clinical and safety monograph for LOGEN (LOGEN).

Breastfeeding	Excreted in breast milk at low concentrations; M/P ratio approximately 0.3. Considered compatible with breastfeeding but monitor infant for adverse effects.
Teratogenic Risk	Limited human data; animal studies show no teratogenicity at therapeutic doses. First trimester: insufficient evidence for major malformations. Second and third trimesters: risk of premature closure of ductus arteriosus and oligohydramnios with prolonged use.
Fetal Monitoring