The allergy medication Benadryl typically stays in the system for four to six hours. Most products instruct users to take the stated dosage every four to six hours as needed, while not exceeding six doses in a single day, per instructions on the package label.Continue Reading
The antihistamine provides temporary relief from seasonal allergies, hay fever, allergic reactions and other upper respiratory allergies and is also effective in treating runny nose and itchy or watery eyes.
Benadryl is available in capsule, tablet and liquid form and as a topical analgesic.
Common side effects of the drug include sedation, tiredness, sleepiness, dizziness, disturbed coordination, drying and thickening of oral and other respiratory secretions and stomach distress, according to the medical experts at rxlist.com.Learn more about Medications & Vitamins
A side effect of Benadryl is that it causes drowsiness, which can make people fall asleep. Numerous over-the-counter sleep aids contain antihistamines such as diphenhydramine and doxylamine succinate because of their potent sedative effects.Full Answer >
The lethal dose of diphenhydramine, the generic name of Benadryl, varies significantly from person to person because of differences in weight and metabolism. There have been cases of people experiencing overdose symptoms with 500 milligrams of diphenhydramine and some cases where overdose is as high as 2,800 milligrams.Full Answer >
The pediatric dosage of Benadryl, or diphenhydramine, depends on the child's weight and the formula used, according to the St. Louis Children’s Hospital. For example, the recommended dose of liquid 12.5-milligram suspension is 3/4 teaspoon for children weighing 20 to 24 pounds.Full Answer >
Benadryl brand products provide relief from itchy skin, which is medically referred to as pruritus. Benadryl's Itch Stopping Topical temporarily alleviates itching and discomfort related to sunburn, minor skin injuries, mild skin irritations, insect bites and skin poisoning, states WebMD.Full Answer >