Timing Your Medication Make an Appointment Ask a Question Search Conditions Allergy and asthma sufferers can maximize the benefit of their medications by taking advantage of their bodies' natural circadian rhythms. Circadian rhythms are the daily variations in biological functions, from mental alertness to blood pressure and body temperature. Blood pressure generally peaks around 9 pm and is lowest at about 3 am, while mental performance and strength both peak at about 3 pm. Allergies and asthma also follow significant circadian rhythms. Allergies Can Trigger Asthma Allergies can trigger asthma symptoms in many patients. Asthma symptoms generally worsen almost immediately after exposure to the allergen. But some patients also suffer a "late asthmatic response" about six to eight hours later. The timing of the allergen exposure can affect this delayed response. Studies have shown that about half of asthmatics exposed to allergens in the morning experience the late asthmatic response. But when they are exposed to the allergen in the evening, virtually all asthma patients develop the late asthmatic response. It is highly recommended that asthmatics who come into contact with an allergen in the evening be especially careful about monitoring symptoms and taking asthma medications. Peak Asthma Symptoms Asthma symptoms generally peak at about 4 am. One scientific study showed three quarters of asthma patients wake up during the night with asthma symptoms at least once a week. For severe asthmatics on oral steroids, taking them at 3 pm helps reduce nighttime symptoms. Asthma Medications - Your Best Strategies Inhaled steroids are a more widely used medication for people with mild to moderate asthma. Studies have shown that inhaled steroids have their greatest effect when taken between 3 pm and 5:30 pm. However, most inhaled steroids are taken two or more times a day, and research has not yet determined the best times to take the multiple doses. The most important strategy for inhaled steroids is to be consistent. Taking them in conjunction with regular events, such as breakfast and dinner, is a good way to make sure that you maintain adequate medication in your system. This information has been approved by Rafeul Alam, MD (February 2014).