Diphenhydramine: Side Effects, Uses & Monitoring
Epinephrine injection is indicated in the emergency treatment of allergic reactions (Type I) including anaphylaxis to stinging insects (e.g., order Hymenoptera, which includes bees, wasps, hornets, yellow jackets and fir
- Data source
- FDA labeling via NIH DailyMed (label 58d78805…)
- Label version
- current
- Last reviewed
- 2026
Reported adverse reactions
Reactions listed in current FDA labeling, with the highest frequency reported across summarized placebo-controlled trials.
No structured frequency data available in current labeling. Consult the official label.
Labeled uses (from FDA prescribing information)
Epinephrine injection is indicated in the emergency treatment of allergic reactions (Type I) including anaphylaxis to stinging insects (e.g., order Hymenoptera, which includes bees, wasps, hornets, yellow jackets and fire ants), and biting insects (e.g., triatoma, mosquitoes), allergen immunotherapy, foods, drugs, diagnostic testing substances (e.g., radiocontrast media), and other allergens, as well as idiopathic anaphylaxis or exercise-induced anaphylaxis. Epinephrine injection is intended for immediate administration in patients who are determined to be at increased risk for anaphylaxis, including individuals with a history of anaphylactic reactions. Anaphylactic reactions may occur within minutes after exposure and consist of flushing, apprehension, syncope, tachycardia, thready or unobtainable pulse associated with a fall in blood pressure, convulsions, vomiting, diarrhea and abdominal cramps, involuntary voiding, wheezing, dyspnea due to laryngeal spasm, pruritus, rashes, urticaria, or angioedema. Epinephrine injection is intended for immediate administration as emergency supportive therapy only and is not a replacement or substitute for immediate medical care.
Conditions associated with Diphenhydramine in labeling
Diarrhea
Loose, watery stools occurring more than three times a day, which can be acute or chronic....
Fainting (Syncope)
A brief loss of consciousness due to a temporary drop in blood flow to the brain....
Shortness of Breath
A feeling of being unable to catch your breath or get enough air, which can be sudden or gradual....
Urticaria
Raised, itchy, red welts (hives) that appear on the skin, often as an allergic reaction, and usually resolve w...
Frequently Asked Questions
What is Diphenhydramine used for?
FDA labeling lists the approved uses shown above under "Labeled uses." This summary is informational; only a qualified prescriber can determine whether a medication is appropriate for you.
What are the most commonly reported side effects of Diphenhydramine?
Current labeling for this ingredient does not include a structured frequency table that we can reproduce. Review the official label linked below.
Does Diphenhydramine require lab monitoring?
Monitoring needs vary. Ask your healthcare provider whether any lab tests apply while taking Diphenhydramine.
Where does this information come from?
All clinical facts on this page were extracted from the current FDA-registered product labeling for this ingredient, published by manufacturers through NIH DailyMed. See the source link below.
Medical disclaimer: Educational content extracted from public FDA labeling. Not medical advice. Always consult a qualified healthcare professional before starting, stopping, or changing any medication.