Why Isn't My Medicine Working?

Kedar Gurjar , PharmD Candidate 2010

Bernard J Dunn School of Pharmacy, Shenandoah University

Prepared during Consumer Health Information Corporation Clerkship
McLean, VA

Questions and answers about why you may think your medicines are not working.

Working in a pharmacy for the past four years I have often heard patients tell me that their drugs do not work. It is important to understand that there are numerous factors that can decrease a drug’s effectiveness. Most causes can be avoided while some may not. By consulting your doctor, pharmacist, or even a reliable healthcare website you can educate yourself about your own medicines and avoid these causes. The following questions and answers should be taken into account when assessing the effectiveness of your medicine. 

Q. When should I expect the drug to start working?

A. Some drugs are not meant to work right away. It may take weeks or months for a medicine to work. Antidepressants, for example, can take up to four to five weeks for their effects to be felt.  It is important to find out when you should expect to see improvement in your condition so that you can monitor your progress properly.    

Q. Are there any special instructions for taking the drug?

A. Every medicine comes with instructions on how to take it correctly. If you do not take these medicines correctly, you may not receive the full benefit of the drug. For example, oral liquid suspensions must be shaken well every time you take it. By doing so the drug is mixed throughout the liquid evenly and the right dose is given. Make sure you understand the correct way to use your drug.

Q. When does the drug expire?

A. The ability of a drug to work decreases over time. Expiration dates are required by law to be written on every prescription drug vial. Drugs taken after the date may not work safely and effectively. Check your medicine bottles for expiration dates so that you are not taking outdated and ineffective drugs. 

Q. Are there any special storage instructions?

A. Each drug needs to be stored correctly to work properly. While most medicines on the shelves may need to be kept dry and at room temperature, some may need to be stored in the refrigerator. Others may need to be kept out of light and in the original container. 

Q. Can any foods interact with my drug?

A. Sometimes the food you eat can interact with the drugs you are taking. For example, Vitamin K is responsible for forming blood clots in the body. Eating a lot of green leafy vegetables which are high in vitamin K can negate the effects of warfarin, a drug that reduces clots.  

Q. Can any of my other medicines interact with this drug?

A. Sometimes you might be taking more than one medicine for different conditions.  Certain medicines can decrease the effectiveness of other medicines. For example, phenytoin, a seizure medicine, can decrease the effects of warfarin. It is important to let your doctor know all the medicines you take so he/she can prescribe accordingly. It is also important to fill all your prescriptions at the same pharmacy so that the pharmacist can review potential drug interactions in their computer system. 

Q. Will smoking cause any interactions with my drug?

A. Along with causing other health problems, smoking can also decrease the effects of drugs such as certain oral pain and asthma medicines.

Q. Am I taking the proper drug?

A. In many cases, finding out what drug works best for each person is a matter of trial and error. The drug that works for one person may not work well for you because we all process drugs differently in our bodies. Higher doses are sometimes needed if the drug is wearing off or the disease has progressed. Discuss with your doctor if you have any concerns that the drug may not be working right for you.  Your doctor will decide whether the dose needs to be changed or if you need a different drug.

Conclusion

If you suspect that your medicine is not working, discuss your concern with your doctor or pharmacist. Always speak to your doctor first before stopping your medicine or changing your dose. Some medicines must be stopped slowly over a period of days or weeks and may require additional monitoring. The safest thing to do is always work closely with your doctor and keep your doctor informed of your progress.   

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