The global Medicine Safety Week starts today, and Bulgaria is taking part again. The campaign runs until 8 November, the Bulgarian Drug Agency (BDA) said.
Every side effect from a medicine should be reported, not passed over, so that other people are not harmed.
More than 139 organisations from over 129 countries are taking part this year, and the campaign's messages will be shared in more than 60 languages.
The BDA asks patients and health professionals to watch for any side effects and report them. Its website has separate forms for patients and for medical staff.
Medicines save lives and improve the health of millions of people worldwide, but they can sometimes cause unexpected side effects, the agency says. Some appear suddenly, while others develop slowly, at times after long use of a medicine. Some show up as clear clinical signs, while others are "silent" and only come to light in tests.
The risk is higher when a person starts a new medicine, changes the dose, or takes the medicine together with other medicines, certain foods or herbal products.
People who are not sure their symptoms come from a medicine can also file a report. The BDA says such reports give data on the safety of medicines and help regulators, the agency among them, to respond to any possible risk.
People can also support the campaign on social media with posts that include #MedSafetyWeek and information from the BDA website.