Many individuals take their medications at times of the day that are convenient or easy to remember -- in the morning, at lunchtime, or before bed, for example. But this strategy may not always give you the most benefit. Instead, an approach called chronotherapy takes into account your body's rhythms to tailor the timing and dosage of your drugs so that they work better and produce fewer side effects.
The human body follows multiple natural rhythms to regulate physiological functions and behavior. The most important one for chronotherapy is circadian rhythm -- your body's daily biological clock that follows the sun's 24-hour cycle and regulates sleeping and waking. Circadian rhythm also affects important biological processes such as hormone secretion, cell growth, and metabolism.
Biological rhythms are known to influence health. For example, jet lag describes the unpleasant symptoms we experience after breaking with the normal circadian rhythm of sleeping and waking related to travel. Scientists have also discovered that biological rhythms play a role in disease and its treatment, since these rhythms cause symptoms to vary throughout the day. Consequently, chronotherapy times administration of a drug so that its peak concentration in the blood occurs around the time of day when the symptoms are worst -- not necessarily because the drug works any better at that time.
Studies to date suggest that by timing drug therapy to biological rhythms, it is possible to reap greater benefits with fewer downsides. For example, symptoms of allergic rhinitis, a condition that affects the mucus membranes of the nose and includes seasonal allergies (hay fever), are often worst in the morning when histamine levels in the body are elevated. That's why some allergists recommend that individuals take a long-acting antihistamine drug at bedtime so it will be in their systems when they wake up.
Chronotherapy is an active area of research, and its applications may extend to other health conditions. For example, researchers have discovered that cholesterol production in the liver appears to be higher in the evening, whereas many people take their cholesterol-lowering statin drugs in the morning. The timing of statin therapy and other drug treatments may change in the future if clinical trials show a benefit to watching the clock as we take our drugs. In the meantime, ask your doctor or pharmacist for the ideal time to take your prescription drugs. Most important, never change the timing of your drugs without first consulting your physician.
