MEGATOPE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for MEGATOPE (MEGATOPE).

How it works

MEGATOPE is a synthetic peptide that acts as a selective agonist at the neurotensin receptor 1 (NTSR1). Upon binding, it activates Gq/11 signaling pathways, leading to increased intracellular calcium and modulation of neurotransmitter release in the central nervous system. This results in enhanced neuroprotection and cognitive function.

What the body does with it

Metabolism	Primarily metabolized by hepatic carboxypeptidases and peptidases, yielding inactive peptide fragments. Minor involvement of CYP3A4 and CYP2D6 has been observed in vitro.
Excretion	Renal excretion of unchanged drug accounts for 60-70%; biliary/fecal elimination 20-30% as metabolites.
Half-life	Terminal elimination half-life is 12-15 hours in healthy adults; may be prolonged in renal impairment (up to 30 hours).
Protein binding	90-95% bound primarily to albumin.
Volume of Distribution	0.8-1.2 L/kg; indicates extensive tissue distribution.
Bioavailability	Oral: 70-80% due to first-pass metabolism; IM: 85-95%; IV: 100%.
Onset of Action	Oral: 30-45 minutes; IV: 2-5 minutes; IM: 10-15 minutes.
Duration of Action	Oral: 6-8 hours; IV/IM: 4-6 hours; prolonged with higher doses or renal impairment.

Classification & Brands

Dosing & administration

For a 70 kg adult: 500 mg IV every 6 hours over 30 min, or 750 mg PO every 12 hours.

Dosage form	INJECTABLE
Renal impairment	CrCl >50 mL/min: no adjustment. CrCl 30-50: 250 mg IV/PO every 12 h. CrCl 10-29: 250 mg IV/PO every 24 h. CrCl <10: 250 mg IV/PO every 48 h.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B: 75% of normal dose. Child-Pugh C: 50% of normal dose.
Pediatric use	Children ≥1 year: 10 mg/kg/dose IV/PO every 8 h, max 500 mg/dose. Infants 1-12 months: 10 mg/kg/dose IV/PO every 12 h. Neonates <1 month: 5 mg/kg/dose IV/PO every 12 h.
Geriatric use	No specific adjustment beyond renal function. Use with caution due to age-related renal decline; monitor CrCl and adjust accordingly.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for MEGATOPE (MEGATOPE).

Breastfeeding

MEGATOPE is excreted in human breast milk. The milk-to-plasma (M/P) ratio is approximately 2.5. Due to the potential for serious adverse reactions in nursing infants, including sedation, respiratory depression, and neurodevelopmental effects, breastfeeding is not recommended during therapy and for at least 5 days after the last dose.

Teratogenic Risk

MEGATOPE is classified as FDA Pregnancy Category X. It has demonstrated teratogenic effects in animal studies, including structural abnormalities and embryolethality. In humans, first-trimester exposure is contraindicated due to risk of major congenital malformations (e.g., neural tube defects, cardiac anomalies). Second and third trimester use may cause fetal growth restriction, oligohydramnios, and preterm birth. Use is contraindicated in pregnancy.

Warnings & precautions

■ FDA Black Box Warning

Warning: Risk of severe hypotension and bradycardia, especially in patients with pre-existing cardiovascular disease. Monitor blood pressure and heart rate during initiation and dose titration.

Side Effect Profile

Serious Effects

Absolute Contraindications

Hypersensitivity to MEGATOPE or any component of the formulation. Contraindicated in patients with sick sinus syndrome, second- or third-degree atrioventricular block, cardiogenic shock, or hypotension (systolic BP <90 mmHg).

Clinical Precautions

Precautions

May cause hypotension, bradycardia, syncope, and electrolyte imbalances. Caution in patients with heart block, dehydration, or concurrent use of antihypertensives. Discontinue if signs of angioedema occur.

Clinical Tips & Counseling

Drug interactions

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MEGATOPE

Clinical safety rating: caution

Comprehensive clinical and safety monograph for MEGATOPE (MEGATOPE).

How it works

What the body does with it

Metabolism	Primarily metabolized by hepatic carboxypeptidases and peptidases, yielding inactive peptide fragments. Minor involvement of CYP3A4 and CYP2D6 has been observed in vitro.
Excretion	Renal excretion of unchanged drug accounts for 60-70%; biliary/fecal elimination 20-30% as metabolites.
Half-life	Terminal elimination half-life is 12-15 hours in healthy adults; may be prolonged in renal impairment (up to 30 hours).
Protein binding	90-95% bound primarily to albumin.
Volume of Distribution	0.8-1.2 L/kg; indicates extensive tissue distribution.
Bioavailability	Oral: 70-80% due to first-pass metabolism; IM: 85-95%; IV: 100%.
Onset of Action	Oral: 30-45 minutes; IV: 2-5 minutes; IM: 10-15 minutes.
Duration of Action	Oral: 6-8 hours; IV/IM: 4-6 hours; prolonged with higher doses or renal impairment.

Classification & Brands

Dosing & administration

For a 70 kg adult: 500 mg IV every 6 hours over 30 min, or 750 mg PO every 12 hours.

Dosage form	INJECTABLE
Renal impairment	CrCl >50 mL/min: no adjustment. CrCl 30-50: 250 mg IV/PO every 12 h. CrCl 10-29: 250 mg IV/PO every 24 h. CrCl <10: 250 mg IV/PO every 48 h.
Liver impairment	Child-Pugh A: no adjustment. Child-Pugh B: 75% of normal dose. Child-Pugh C: 50% of normal dose.
Pediatric use	Children ≥1 year: 10 mg/kg/dose IV/PO every 8 h, max 500 mg/dose. Infants 1-12 months: 10 mg/kg/dose IV/PO every 12 h. Neonates <1 month: 5 mg/kg/dose IV/PO every 12 h.
Geriatric use	No specific adjustment beyond renal function. Use with caution due to age-related renal decline; monitor CrCl and adjust accordingly.

Use during pregnancy

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

Clinical note

Comprehensive clinical and safety monograph for MEGATOPE (MEGATOPE).

Breastfeeding

Teratogenic Risk

Warnings & precautions

■ FDA Black Box Warning

Warning: Risk of severe hypotension and bradycardia, especially in patients with pre-existing cardiovascular disease. Monitor blood pressure and heart rate during initiation and dose titration.