Think about the path a drug follows through your body. Different organs and fluids break it down along the way. Some parts go to work, but other parts are flushed out of the body.

Drugs have been carefully made to take all of that into account. That's why each drug has its own set of directions. Following the directions helps ensure the drugs you take work the way they should. Here are a few factors to keep in mind. 

Time of Day
When you take a drug may make a difference. Some drugs can make you sleepy or keep you awake.

How Far Apart
Drugs last different lengths of time in the body. Some break down and wear off quickly. Others can last a full day or longer. Taking your drug as directed ensures you get the full benefit of the drug. It also helps prevent an accidental overdose. If you take several drugs that need to be taken at different times, use a chart   or alarms to help you keep track.   If you forget a dose, ask your doctor or pharmacist if you should take it right away or wait for the next dose.

With or Without Food (or Certain Foods)
Some drugs must not be taken with certain foods because of their ingredients. If your doctor tells you to take a drug with food, it may be to avoid an upset stomach. If it should be taken on an empty stomach, the drug may have a harder time working if it is competing with your last snack or meal.

With or Without Liquids
Most people take pills with a drink to wash them down. Water is the safest choice. Some drugs should be taken with a lot of water to help them do their best work. Other drugs should not be taken with certain types of drinks, such as juices or dairy.  If you take meds at night, you may need to be careful about any alcohol you consume before or after your dose. With some drugs, you should avoid alcohol.

With or Without Other Drugs (Including Over-the-Counter)
Some drugs can cancel each other out or cause problems if they are taken too close together or together at all. Some drugs are less effective if taken with other drugs that affect digestion (antacids).

How Much
Getting the right dose can be easy if you just take a certain number of pills. But some drugs like liquids or shots must be measured. The amount you take is important. Too little may not work. Too much can be toxic. Pharmacists often provide a measuring cup or spoon with prescriptions.

Take ad Directed

It’s important to continue taking your meds as instructed. For example, take all of your antibiotic. If you don’t, the drug might not kill the bacteria causing infection.

Some people may not take their drugs as directed for other reasons, including

• They can’t afford to pay for the drugs.
• They don’t believe the drug is needed or helps.
• They have a hard time keeping track of several drugs and their directions.
• They may not understand the directions.

Ask for Help

If you are struggling with taking your meds as directed for any reason, ask for help. Your doctor or pharmacist may know of ways to help you pay for prescriptions. They can also offer advice to better manage your schedule.

Sources: Why You Need to Take Your Medications as Prescribed or Instructed,   U.S. Food & Drug Administration, 2016; Get Medicine Reminders,   Script Your Future, 2020.

Originally published January 21, 2016; Revised 2019, 2021