A recent study published in the journal Frontiers in Medicine identified some previously unknown side effects from epinephrine, a life-saving medicine used to treat severe allergic reactions.
Many people with conditions like systemic mastocytosis (SM) carry epinephrine auto-injectors (EpiPens) because allergic reactions can happen quickly and be dangerous. While epinephrine can save lives, it can also cause side effects.
This study looked at reports of epinephrine side effects listed in the U.S. Food and Drug Administration Adverse Event Reporting System from 2004 to 2024. Researchers analyzed 9,262 reports regarding epinephrine and found 264 different side effects.
The most commonly reported problem was that the medicine didn’t seem to work; this accounted for 1,867 reports out of 9,262.
A serious side effect called injection site ischemia (when blood flow to the injection area is blocked) had the strongest link to epinephrine use.
The study also identified some rare but important side effects that are not listed on current drug labels. These included myocardial stunning (a temporary weakening of the heart), systolic anterior motion of the mitral valve (when a flap in the heart moves the wrong way), left ventricle outflow tract obstruction (a blockage in the heart), harlequin syndrome (one side of the face turns red while the other stays pale), injection site nerve damage and problems with movement at the injection site.
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“Our findings corroborate previously recognized adverse reactions documented on the drug’s labeling information, and notably, we identified several previously unreported adverse event signals,” the researchers said.
The study found that most side effects happened quickly, often on the same day as the injection and usually within 24 hours. This is why people who get epinephrine should be watched closely by a doctor or nurse during this period.
Further clinical studies are needed to confirm the findings of this study and understand what causes the side effects, the researchers said.
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