Timing is key for some prescription drugs

The next time you pick up a prescription refill, take a moment to read the labels affixed to the container. You might find some very specific advice, including a caution to take the drug at a specific time of day.

Does it really matter when a prescription drug is taken? In many cases it does, says Leiana Oswald, a doctor of pharmacy and assistant professor of pharmacy practice at Roseman University of Health Sciences in Henderson.

Take, for instance, a statin prescribed for someone who has high cholesterol. It’s not uncommon for statin labels to specify that the drug be taken “before bedtime,” Oswald says.

Note that the instructions won’t say “at nighttime,” Oswald adds, but, rather, ‘before going to sleep.’ ”

That’s because “the body synthesizes cholesterol while you sleep, and if you take it right before bed, there’s potentially going to be more benefit,” Oswald says.

Other medications may bear instructions that the drug be taken at other times of the day, and those instructions may be designed also with consideration of how an individual patient reacts to the drug.

Some, for instance, may be instructed to take a hypertension medication “in the morning, because you get control of (blood pressure) throughout the day,” Oswald says. “For some patients who take blood pressure medication, it makes them dizzy and lightheaded and it’s better to take it before going to sleep, to sleep through those side effects.”

Meanwhile, other drugs may carry instructions that they be taken with meals — for instance, nonsteroidal anti-inflammatory drugs such as ibuprofen or aspirin, which can cause stomach upset or even ulcers if taken on an empty stomach — and some diabetes medicines taken at the wrong time or on an empty stomach also can cause adverse reactions, Oswald says.

The bottom line: Take drugs in the way, and at the time, they’re intended to be taken, and consult your health care provider if you have any questions.

Another bit of advice: Take advantage of your pharmacist’s offer of counseling. Pharmacists are required by law to counsel patients about prescription medications they dispense, Oswald says, “but if the patient refuses that counsel, at that point it’s out of our hands.”

On a related note, a reader, following up on a previous Health Q&A about how grapefruit juice shouldn’t be ingested while taking some drugs, asks if it’d be OK to eat grapefruit for breakfast eight to 10 hours after having taken a statin the night before.

Grapefruit and grapefruit juice can affect the way in which some drugs, including some statins, are metabolized, to potentially harmful effect. But, Oswald says, even after a night’s worth of sleep, someone can still run the risk of the grapefruit juice interaction with the statin, increasing its effect.

“(So) as a general rule, we just recommend to stay away,” she says. “It’s hard for patients to know what the cutoff line is.”

Contact reporter John Przybys at jprzybys@reviewjournal.com or 702-383-0280.