Saralasin

Summary

Saralasin is a synthetic octapeptide analogue of angiotensin II that acts as a competitive, partial agonist/antagonist at angiotensin II receptors. It was used investigationally to diagnose and treat renin-dependent hypertension but was never approved for clinical use due to its partial agonist activity, short half-life, and requirement for intravenous administration. It was largely superseded by non-peptide angiotensin II receptor blockers (ARBs) and ACE inhibitors.

Mechanism of Action

Competitive antagonist of angiotensin II at AT1 receptors; partially acts as a partial agonist. Blocks vasoconstriction and aldosterone release mediated by angiotensin II, leading to reduction in blood pressure in renin-dependent hypertension.

Routes of Administration

Goals & Uses

• Research tool for RAS characterizationResearchHigh
• Antihypertensive effect in high-renin statesCardiovascularModerate
• Diagnosis of renin-dependent hypertensionDiagnosticModerate

Contraindications

• Low-renin hypertension or normal renin statesCardiovascularHigh
• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Sodium depletionMetabolicModerate

Adverse Effects

• HypotensionCardiovascularCommonLow blood pressure
• FlushingVascularUncommonWarmth and redness of the skin
• NauseaGastrointestinalUncommonFeeling of sickness or urge to vomit
• Hypertension (paradoxical)CardiovascularCommon

Drug Interactions

• ACE inhibitorsModerate
• DiureticsModerateMay worsen dehydration or electrolyte imbalance

Population Constraints

• Pediatric patientsAgeRelative
• Patients with normal or low renin activityCardiovascularAbsolute
• Pregnant womenReproductiveAbsolute

Regulatory Status

• European UnionUnapprovedNo EMA approval; historical research use only.
• United StatesUnapprovedUsed investigationally in the 1970s–1980s; never received FDA approval. No active IND on record for modern use.
• United KingdomUnapprovedNo MHRA approval; used only in research context historically.

Never received FDA approval for therapeutic use. Used primarily as a research and diagnostic tool for renin-angiotensin system studies in the 1970s–1980s. No longer in active clinical or investigational development.

Evidence & Sources

No sources recorded yet.