I consumed two Panadol (paracetamol) tablets for headache. Later only I noticed that the medicine had expired about a month ago. Even two days after consuming I did not feel anything unusual. Will this be harmful for my health. Is it safe to use recently expired medicines in case of necessity?
Medicinal substances have a defined shelf-life after which it may become less effective. This is denoted in the package as expiry date. Usually the shelf-life is between 12 to 60 months for most medications. When the expiry date is passed, the medicine should be discarded.
It is a common belief that the medicine become poisonous after the expiry date. The only expired medication that has ever been reported to cause toxicity was an older tetracycline (an antibiotic) formulation that is now off the market. The rest of the medications only lose their potency after the expiry date. This decline in potency greatly varies between individual drugs.
A study was carried out in the US to check the potency of 3000 medications which were 1 year past expiry date. Interestingly, 90% of them were found to be 90% effective. But these were stored in optimal conditions. In another study, 8 drugs which were discovered after 30-40 years in a retail pharmacy were examined. They were in their unopened, original containers. Nearly half of them were found to be fully potent after 40 years. But the two commonly used medications; paracetamol and aspirin had decayed significantly.
It is important to note that suspensions and topical solutions are less stable. Suspensions should be discarded after few weeks of opening the container. They are susceptible to freezing as well. The topical solutions such as eye/ear/nose drops can be used for 4-8 weeks after opening the container. Solution that have become cloudy or discolored or show signs of precipitation should not be used. Always refer to the product label for each individual medication.
In the above scenario where a person has consumed paracetamols after a month of expiry, it is highly unlikely to be harmful. But it would have been less effective for his ailment.
- 2015. “Drugs Past Their Expiration Date.” The Medical Letter. December 07. Accessed August 09, 2020. http://svmi.web.ve/wh/documentos/Drugs-Past-Their-Expiration-Date.pdf.
- GW, Frimpter, Timpanelli AE, Eisenmenger WJ, Stein HS, and Ehrlich LI. 1963. “Reversible “Fanconi Syndrome” Caused by Degraded Tetracycline.” JAMA 184 (2): 111-113. doi:10.1001/jama.1963.03700150065010.
- L, Cantrell, Suchard JR, Wu A, and Gerona RR. 2012. “Stability of Active Ingredients in Long-Expired Prescription Medications.” Arch Intern Med 172 (21): 1685–1687. doi:10.1001/archinternmed.2012.4501.
- Lyon, Robbe C, Jeb S Taylor, Donna A Porter, Hullahalli R Prasanna, and Ajaz S Hussain. 2006. “Stability profiles of drug products extended beyond labeled expiration dates.” Journal of Pharmaceutical Sciences 95 (7): 1549-1560. doi:10.1002/jps.20636.