Antihistamines are designed to block the effects of the histamine that your body produces.
In turn, they decrease the symptoms of the allergy.
Its daytime counterpart is antihistamine free Day Quil, formulated to avoid drowsiness. Ny Quil D contains pseudoephedrine, a decongestant that in some regions (such as the United States) is now placed behind the counters at pharmacy and other retail stores and must be requested by the customer.
It contains the following active ingredients (15 m L is one tablespoon, half the recommended adult dose): Previously, Ny Quil Cold/Flu Multisymptom Relief and Ny Quil Sinus contained pseudoephedrine (30 mg/15 m L), a nasal decongestant that also formed the active ingredient in Sudafed.
Some antihistamines may also be helpful in reducing anxiety, inducing sleep, or at preventing or treating motion sickness.
Zyrtec and Claritin have very few side effects and are generally recognized as safe for most people. Zyrtec can cause sleepiness, but only in some people.
Take it for the first time when you will be at home for a few hours in case it makes you sleepy.
They both calm your immune system’s reaction to allergens. They also take effect at different times and stay effective for different durations. Antihistamines have a reputation of making you sleepy because the first types crossed into your central nervous system more easily and had a direct effect on your alertness.
These factors could determine which of these two drugs is better for you. However, newer antihistamines like Zyrtec and Claritin are less likely to cause this side effect. Most people experience at least 24 hours of relief after a single dose. People who take it may feel relief in as little as one hour.