Last reviewed 2026-04-20 · How we verify

Epipen (epinephrine)

Epipen works by stimulating the alpha-1D adrenergic receptor to rapidly increase heart rate, blood pressure, and bronchodilation.

Epipen (epinephrine) is a small molecule catecholamine that targets the alpha-1D adrenergic receptor. Originally developed, it is now owned by Ph Health and has been FDA-approved since 1948 for various indications including anaphylaxis, asthma management, and allergic reactions. Epipen is off-patent with 7 generic manufacturers available. Key safety considerations include potential cardiovascular and neurological effects. As a medication, Epipen is used to rapidly alleviate severe allergic reactions.

At a glance

Mechanism of action

Epinephrine acts on both alpha ()- and beta ()-adrenergic receptors. The mechanism of the rise in blood pressure is 3-fold: direct myocardial stimulation that increases the strength of ventricular contraction (positive inotropic action), an increased heart rate (positive chronotropic action), and peripheral vasoconstriction.

Approved indications

• Acute exacerbation of asthma
• Administration of Local Anesthetic Nerve Block
• Allergic Reactions
• Anaphylaxis
• Asthma management
• Bronchiectasis
• Bronchitis
• Dyspnea
• Exacerbation of asthma
• Hypotension associated with septic shock
• Local anesthesia, by infiltration
• Low blood pressure
• Open-angle glaucoma
• Pulmonary emphysema
• Wheezing

Common side effects

• cardiac arrhythmias
• excessive rise in blood pressure
• cerebral hemorrhage
• hemiplegia
• subarachnoid hemorrhage
• anginal pain
• anxiety
• restlessness
• throbbing headache
• tremor
• weakness
• dizziness

Drug interactions

• Inhalational Anesthetics
• isocarboxazid
• labetalol
• linezolid
• methylthioninium chloride
• metoprolol
• nadolol
• penbutolol
• phenelzine
• pindolol
• procarbazine
• propranolol

Key clinical trials

• A Clinical Study of Ifinatamab Deruxtecan (I-DXd) in People With Metastatic Prostate Cancer (MK-2400-001) (PHASE3)
• Testing the Addition of the Anti-cancer Drug Venetoclax and/or the Anti-cancer Immunotherapy Blinatumomab to the Usual Chemotherapy Treatment for Infants With Newly Diagnosed KMT2A-rearranged or KMT2A-non-rearranged Leukemia (PHASE2)
• Testing Trametinib as a Potential Targeted Treatment in Cancers With GNAQ or GNA11 Genetic Changes (MATCH-Subprotocol S2) (PHASE2)
• Efficacy and Safety of Fully Resorbable Sinus Drug-eluting Stents in Patients With Eosinophilic Chronic Rhinosinusitis With Nasal Polyps After Surgery: A Prospective, Randomized Controlled Trial (NA)
• Clinical and Molecular Characteristics of Primary Aldosteronism in Blacks
• Treatment Strategies for IgG4-RD Patients With Superficial Organ Involvement (NA)
• Sleep Loss and Circadian Misalignment - Mechanisms of Insulin Resistance (PHASE4)
• Parenting and CAH - 21-hydroxylase Deficiency

Patents

Primary sources

Every claim on this page is sourced from regulatory or scientific primary sources. See our editorial policy for full methodology.

Competitive intelligence

For the full competitive landscape — auto-detected comparators, recent regulatory actions across the set, upcoming PDUFA, patent timeline, sponsor landscape:

• Epipen CI brief — competitive landscape report
• Epipen updates RSS · CI watch RSS
• Pfizer Inc. portfolio CI