Benefits of a well-timed drug

Some drugs are early birds that work better in the morning, while others are night owls that peak late at night. What time, exactly, depends on the part of the body the drug affects. That’s because many cells in your body have schedules all their own, known as circadian rhythms, set by a biological clock in your brain and loosely based on a 24-hour cycle. Researchers in the budding field of chronobiology study those clocks to determine when various health products work best. For example, applying antiperspirants before bed allows them to work overnight, when body temperature and perspiration drop, and effectively prevents wetness and odor when they peak the following day. Below are examples of how the proper timing of medications can increase their effectiveness and minimize their side effects.

Arthritis
The pain and stiffness from rheumatoid arthritis, the less common but more serious form of the disease, generally build overnight and peak in the morning. So about an hour before bedtime and after waking up may be the best times for taking over-the counter nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil and generic) or naproxen (Aleve and generic). Corticosteroids used for more severe rheumatoid arthritis are best taken in the morning.  Pain from osteoarthritis, on the other hand, tends to worsen through the day, often peaking in the afternoon or evening. People who require an NSAID to manage their pain should consider taking it before the symptoms typically start—at breakfast if they experience afternoon pain, for example, or at lunch to prevent evening flare-ups.

Asthma and Hay Fever
At night the body secretes more of the histamines that can trigger allergy and asthma attacks, and less of certain hormones that can combat the narrowing of airways. So it makes sense to take some drugs in the evening, including antihistamines and leukotriene-receptor antagonists such as montelukast (Singulair) and zafirlukast (Accolate). A time-released formula of the asthma drug theophylline (Uniphyl) is designed to peak overnight when it’s most needed.  But intranasal steroid sprays used to reduce inflammation should usually be taken in the morning. That’s because most of those drugs, such as beclomethasone (Beconase AQ) and budesonide (Rhinocort Aqua) for allergies, are more prone to cause side effects when taken at night.

Cancer
The anticancer drug fluorouracil, often used to treat malignancies of the breast and colon, is best given at night when cancer cells are most vulnerable to the drug and healthy cells in the gastrointestinal tract are most resistant to the drug’s toxic effects. Similarly, research suggests that chemotherapy for leukemia in children seems to work best when given in the evening.

High Blood Pressure
Many heart problems occur early in the morning, when blood pressure tends to spike. Researchers have tried to compensate by developing drugs that target overnight and morning rises in blood pressure, such as long-acting diltiazem (Cardizem-LA and generic) and controlled-onset extended-release verapamil (Covera-HS, Verelan PM, and generic). But consult your doctor before trying to time your blood pressure medicines to the biological cycle. Some people, especially seniors, may experience dangerous drops in nighttime blood pressure.  And taking some diuretics before bed may interfere with sleep by increasing the need to urinate.

Ulcers And Heartburn
Stomach-acid secretion normally spikes at night, when heartburn and stomach ulcers can worsen. So it often makes sense to take relatively fast-acting H2-blockers such as famotidine (Pepcid and generic) and ranitidine (Zantac and generic) with dinner. In contrast, protonpump inhibitors such as lansoprazole (Prevacid) and omeprazole (Prilosec and generic) are usually best taken in the morning. But since heartburn varies among individuals, try to adjust the timing to prevent your symptoms.

Insomniacs Beware
Many medications, including asthma drugs, beta-blockers, and oral decongestants, can keep you up at night. So if you experience sleep problems, ask your doctor if you can take your medication at another time, or if another drug might work just as well.

Also ask if timing affects other drugs you regularly take, but be prepared to bring some research. “Most doctors and pharmacists know little about chronotherapy,” says Michael Smolensky, Ph.D., director of the Hermann Hospital Chronobiology Center at the University of Texas in Houston, and author of “The Body Clock Guide to Better Health.”
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