Is it a cause for concern, when I take Kwelux SR I am very sleepy and I have the impression that I am about to fall, faint?

Thank you for sharing your case. According to the Summary of Product Characteristics, somnolence is one of the common side effects of Kwelux SR and may disappear with continued use: https://www.gdziepolek.pl/produkty/41768/kvelux-sr-tabletki-o-przedluzonym-uwalnianiu/apteki Please note that side effects of medicines should be reported to your doctor or individually. By reporting side effects, you help other patients, including your relatives, who may also need the same medicine one day. This step also allows you to gather more information on the safety of medicinal products and to update data on them. I encourage you to report an adverse reaction if you have not already done so: https://www.gdziepolek.pl/artykuly/jak-i-dlaczego-zglaszac-dzialania-niepozadane