Learn how to take BENADRYL® products with this helpful dosing guide. Take 1 capsule every 4 to 6 hours or as directed by a doctor. Under 6. Do not use. Benadryl (diphenhydramine) is a brand-name, over-the-counter product oral tablets; oral liquid-filled capsules (liqui-gels); oral chewable. Pill with imprint Benadryl is Clear, Capsule-shape and has been identified as Benadryl Allergy Liqui-Gels 25 mg. It is supplied by McNeil Consumer Healthcare . Orr, S. Schutte-Rodin, S. However, if you're taking Benadryl frequently on more than about four days per weektalk with your doctor. Hematologic System: Hemolytic anemia, thrombocytopenia, agranulocytosis. There is no proven risk in humans during pregnancy. Diphenhydramine side effects in more detail. After oral administration, the onset of action is approximately 15 to 30 minutes. Tell your doctor and pharmacist about all of your drugs prescription or OTC, natural products, vitamins and health problems. Allegra fexofenadine is a newer, second-generation antihistamine. If you are using Benadryl liquid, do not use a kitchen teaspoon to measure a dose. There is very little scientific research about the long-term effects of Benadryl. Over-the-counter Benadryl products aren't approved to cqpsule symptoms of motion sickness. Q: Is Benadryl safe for use in people with asthma? Benadryl can eia asthma with falling asleep in people with occasional sleeplessness. It can make you feel sleepy, which might temporarily make you feel less anxious. If you take Zyrtec, talk with your doctor before taking Benadryl. The diagnosis and management of acute and chronic urticaria: update. Both products can help with falling asleep in people with occasional sleeplessness. Over-the-counter Benadryl products aren't approved to treat sinus pain. A: Benadryl diphenhydramine is an antihistamine used to treat allergies.