Ask the Pharmacist

Q. Last week you discussed food/drug interactions which I found very enlightening. Can you discuss the importance of taking my medications in the morning vs evening or vice versa?

A. There are many medications that the time of day at which it is taken really does not matter and the time chosen would be up to each individual keeping in mind that the determining factor should probably be what is the easiest for you to remember. This is because one of the main keys to achieving the best results from a medication, regardless of whether your drug is once a day or more often, is consistency with respect to when it is taken.

Now, let’s discuss the medications that are more prudent to be taken in the morning.

For those of you that have had to take a diuretic (aka water/fluid pill), you would likely already know it is best to take that in the morning. The diuretic works by taking the excess fluid that your body is retaining and excreting it by way of urination. If you do take them later in the day, your sleep might be affected by nighttime trips to the bathroom (or should I say more trips as many of us already have noticed that as we mature, frequent bladder related interruptions to our rest is simply a fact of life).

Levothyroxine is another medication that is best suited for morning administration. Recall from last week when we discussed that it should be taken 60 minutes before breakfast which also includes coffee by the way!) as this will ensure a truly empty stomach and give it an optimum absorption. There are studies done with evening dosing of levothyroxine for people that just cannot manage the 60 minutes before breakfast and coffee. If choosing evening administration, ensure that it is at least 2 to 4 hours after the last meal of the day. Whichever method you do choose, the key, once again, is consistency!

Another class of medications for morning dosing are the bisphosphonates (alendronate and risedronate) for our bones. These medications can cause esophageal irritation and therefore it is crucial to stay upright for 60 minutes after swallowing which is easier to achieve in the morning.

Prednisone is a corticosteroid and is dosed in the morning to reduce the risk of adverse effects. Prednisone is commonly associated with a surge of energy and if dosed later in the day, you may find yourself cleaning the house in the wee hours of the morning rather than getting a restful sleep. Prednisone has the potential to suppress the hypothalamic-pituitary-adrenal axis (In English terms, this suppression results in your adrenal glands being unable to generate its own cortisol levels) and morning doses help minimize this suppression.

There are also medications that are best taken at bedtime for ideal effectiveness.

Amongst this list are H2 blockers such as ranitidine (Zantac) which helps reduce overnight heartburn symptoms. Shorter acting statins such as Fluvastatin, lovastatin and simvastatin are best in the evening since our cholesterol production is increased when we are sleeping and there is less food in our stomach. If you are on a longer acting statin such as rosuvastatin (Crestor), pravastatin and atorvastatin (Lipitor), you can certainly take them in the morning due to their longer lengths of action.

There are also some evening medications that are obvious for bedtime dosing such as those to help you sleep. What is not so obvious however is that some drugs for insomnia are best taken right before retiring for the night whereas others could be administered anywhere from 1 to 3 hours before bedtime. To further complicate matters, the timing can be further individualized depending upon whether the nature of the sleep problem was in falling or staying asleep.

Beyond the prescriptions that are taken for its desired drowsy effect, there are medications that cause sedation and in order to avoid daytime drowsiness, they should be taken in the evening.

There are also some blood pressure meds that are suggested to be taken in the evening to help reduce the overnight cardiovascular risk you sometimes hear about. It is a well-established fact that the most common time to suffer a cardiovascular accident is during the last few hours of sleep and the first 3 hours of the morning. As such, certain blood pressure medications such as the ACEIs like ramipril and ARBs like telmisartan are more likely to protect you if taken the night before.

Lastly, there are medications that are best suited to be taken in the late afternoon. Warfarin, a blood thinner, is a medication that has a very narrow window for proper blood levels and routine lab work is required to ensure the correct dose is given. Usually the blood is drawn in the morning and a corrected dose can then be given by 6pm that same day.

Some people take gabapentin for restless legs syndrome and it is best administered around 5pm for a peak effect and optimum relief when you need it most.