Drug Effectiveness and Safety

ByShalini S. Lynch, PharmD, University of California San Francisco School of Pharmacy
Reviewed/Revised May 2022 | Modified Sept 2022
VIEW PROFESSIONAL VERSION

The main goals of drug development are demonstrating the effectiveness and safety of the drug. Because all drugs can harm as well as help, safety is relative. The difference between the usual effective dose and the dose that causes severe or life-threatening side effects is called the margin of safety. A wide margin of safety is desirable, but when treating a dangerous condition or when there are no other options, a narrow margin of safety often must be accepted. If a drug's usual effective dose is also toxic, doctors do not use the drug unless the situation is serious and there is no safer alternative.

To help ensure that their treatment plan is as safe and effective as possible, people should keep their health care practitioners well informed about their medical history, drugs (including over-the-counter drugs) and dietary supplements (including medicinal herbs) that they are currently taking, and any other relevant health information. In addition, they should not hesitate to ask a doctor, nurse, or pharmacist to explain the goals of treatment, the types of side effects and other problems that may develop, and the extent to which they can participate in the treatment plan.

Making the Most of Drug Treatment

People can help make their treatment plan as safe and effective as possible by telling the doctor, nurse, or pharmacist:

  • What medical problems they have

  • What drugs (prescription and nonprescription) and dietary supplements (including medicinal herbs) they have taken in the previous few weeks

  • Whether they have or have had any allergies or unusual reactions to drugs, foods, or other substances

  • Whether they follow special diets or have food restrictions

  • Whether they are pregnant, plan to become pregnant, or are breastfeeding

Additionally, people can help by

  • Knowing the brand name, generic name, or both of a drug and knowing what the drug is taken for

  • Reading the label on drug containers carefully before taking a drug, whether prescription or nonprescription

  • Understanding what a drug is being taken for, how to know whether the drug is working, and what side effects are possible

  • Knowing how long the drug should be taken

  • Not drinking alcohol if so advised

  • Not chewing, cutting, or crushing a capsule or tablet unless so instructed

  • Not using household spoons to measure liquid drugs

  • Knowing what to do if they miss a dose

  • Using simple tools like charts or medication organizers to remember to take doses at the correct times

  • Storing drugs in the correct place (cool, dry place; out of sunlight; and away from children and pets)

  • Disposing of expired drugs properly

  • Never taking someone else's prescription drugs

  • Taking recommended preventive steps and participating in recommended health programs

  • Keeping a drug list handy

  • Keeping appointments

  • Seeking medical care promptly when a problem develops

  • Contacting their provider or pharmacist with any questions that may arise

More Information

The following are some English-language resources that may be useful. Please note that THE MANUAL is not responsible for the content of these resources.

  1. The Center for Information and Study on Clinical Research Participation (CISCRP): A nonprofit organization that educates and informs patients, medical researchers, the media, and policy makers about the roles they all play in clinical research

  2. ClinicalTrials.gov: A database of privately and publicly funded clinical studies conducted around the world

Drugs Mentioned In This Article
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