Pentagastrin

Summary

Pentagastrin is a synthetic pentapeptide analogue of the C-terminal tetrapeptide of gastrin, used historically as a diagnostic agent to stimulate maximal gastric acid output for evaluation of gastric acid secretory function. It was also used to stimulate calcitonin secretion as a provocative test for medullary thyroid carcinoma. It has been largely withdrawn or discontinued in many markets due to availability of alternative diagnostic methods and manufacturing discontinuation.

Mechanism of Action

Binds to cholecystokinin-B (CCK-B)/gastrin receptors on parietal cells of the gastric mucosa, stimulating gastric acid secretion; also stimulates secretion of pepsin, intrinsic factor, and pancreatic enzymes, and increases gastric motility.

Routes of Administration

Goals & Uses

• Provocative test for medullary thyroid carcinomaDiagnostic/OncologyHigh
• Research tool for CCK-B receptor pharmacologyResearchModerate
• Evaluation of pheochromocytoma (historical)Diagnostic/EndocrinologyLow
• Gastric acid secretion stimulation (diagnostic)DiagnosticHigh

Contraindications

• Inflammatory bowel disease (acute)GastrointestinalModerate
• Obstructive jaundice / biliary diseaseHepatobiliaryModerate
• PregnancyPopulationModeratePotential fetal risk or insufficient safety data
• Hypersensitivity to pentagastrin or excipientsAllergy/ImmunologyHigh
• Active gastrointestinal hemorrhageGastrointestinalHigh

Adverse Effects

• Anaphylaxis / hypersensitivityImmunologicRare
• Dizziness / lightheadednessNeurologicUncommon
• HypotensionCardiovascularUncommonLow blood pressure
• FlushingVascularCommonWarmth and redness of the skin
• Nausea and vomitingGastrointestinalCommon
• Abdominal cramping / painGastrointestinalCommon

Drug Interactions

• H2-receptor antagonists (e.g., ranitidine, famotidine)Moderate
• Beta-blockersLow
• Proton pump inhibitors (PPIs)High
• Anticholinergics (e.g., atropine)Moderate

Population Constraints

• PregnancyReproductive SafetyRelative
• Patients with severe hepatic or renal impairmentOrgan ImpairmentRelative
• Pediatric patientsAgeRelative
• Elderly patientsAgeRelative

Regulatory Status

• European UnionWithdrawnApproved: Diagnostic stimulation of gastric acid secretionWithdrawn or discontinued in most EU member states; was previously available in several countries.
• United StatesWithdrawnApproved: Diagnostic agent for evaluation of gastric acid secretory function, Provocative test for medullary thyroid carcinoma (calcitonin stimulation)Peptavlon (Ayerst) was previously FDA-approved but manufacturing was discontinued; no longer commercially available in the US.
• United KingdomWithdrawnApproved: Diagnostic agent for gastric acid testing, Provocative test for medullary thyroid carcinomaPreviously available in UK; discontinued. MHRA has no current active marketing authorisation.

Previously approved in the US (Peptavlon) and other jurisdictions as a diagnostic agent; manufacturing was discontinued in the US and many other markets. No longer commercially available in most countries. Historical use for gastric acid testing and MTC screening.

Evidence & Sources

No sources recorded yet.