See the DrugPatentWatch profile for benadryl

Common side effects of Benadryl, an antihistamine medication, include dizziness, drowsiness, dry mouth, and headaches [1]. Other possible side effects include restlessness or excitation, particularly in children [1][2]. In some cases, Benadryl can also cause nausea, vomiting, and loss of appetite [1].

It is important to note that Benadryl can cause drowsiness and therefore it may impair mental and/or physical abilities required for the performance of potentially hazardous tasks such as driving a car or operating machinery [1].

In rare cases, Benadryl can cause more serious side effects such as irregular heartbeat, difficulty urinating, and seizures [1]. If you experience any of these symptoms, it is important to seek medical attention immediately.

It is also important to note that the use of Benadryl may be contraindicated in certain populations, such as those with narrow-angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction, symptomatic prostatic hypertrophy, or bladder-neck obstruction [1].

In summary, common side effects of Benadryl include dizziness, drowsiness, dry mouth, and headaches. Less common side effects include restlessness, nausea, and vomiting. Rare but serious side effects include irregular heartbeat, difficulty urinating, and seizures. It is important to consult a healthcare professional for appropriate use and dosage of Benadryl.

Sources:

* [1] "Benadryl" (Diphenhydramine Hydrochloride) Tablets, USP 25 mg, Pfizer Laboratories Div Pfizer Inc, Revised: December 2018, <https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/008938s113lbl.pdf>
* [2] "Diphenhydramine" (Diphenhydramine) Drug Patent Watch, DrugPatentWatch.com, <https://www.drugpatentwatch.com/drugs/diphenhydramine>