Author: Joana Simões (Pharmacist) #MedSafetyWeek is an annual campaign aimed at both the public and healthcare professionals, with the goal of raising awareness and encouraging the reporting of suspected adverse reactions to medicines. The 2026 campaign runs from 2 to 8 November, under the theme “Don’t ignore suspected adverse reactions. Report them!” Medicines save lives and improve the health of millions of people around the world, but they can also cause unwanted side effects . To monitor the safety of medicines, regulatory authorities rely on reports of adverse reactions submitted by healthcare professionals and members of the public. Unfortunately, fewer than 10% of side effects are reported. What are adverse reactions to medicines? An adverse drug reaction, also known as a side effect, is an unwanted and harmful response that may occur after taking or using a medicine. These reactions can occur in different ways, for example: Skin: itching, redness, spots or rashes. Digestive system: nausea, vomiting, diarrhea or abdominal pain. Nervous system: dizziness, headaches or drowsiness. General wellbeing: excessive tiredness, changes in sleep or mood changes. Some adverse reactions are mild and temporary, while others can be serious and require medical attention. Adverse reactions may occur shortly after starting a medicine or only after weeks or months of use. An adverse reaction may be known or unknown, expected or unexpected. A reaction does not have to be new to be important to report it. Why is it important to report adverse reactions? Reporting suspected adverse reactions helps regulatory authorities to: Identify new or rare adverse reactions. Improve the monitoring of medicine safety. Update safety guidance for healthcare professionals and members of the public. Detect problems with medical devices or other healthcare products. By reporting a possible adverse reaction, you are helping to make medicines safer for yourself and for everyone. One report can make a difference. Remember that your health should always come first. Do not stop taking a prescribed medicine or change the dose on your own without advice from a healthcare professional, except in an emergency, when you should seek medical assistance immediately. If you experience difficulty breathing, swelling of the tongue or throat, fainting or other signs of a severe reaction, go to a hospital emergency department or call the national emergency number (112 in Portugal). Find out more about medicine safety and reporting adverse reactions. Sources: World Health Organization. 2026. #MedSafetyWeek 2026: Don't ignore side effects. Report them . Uppsala Monitoring Centre. 2026. Side effects - don't ignore them, report them. Serviço Nacional de Saúde. 2026. Notificar efeitos indesejáveis dos medicamentos. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item. English translation generated with AI and reviewed by the editorial team.
