Yes, Efracea (doxycycline extended-release) may in rare cases cause muscle and joint pain, as well as numbness in the extremities, which may be a sign of a reaction to the medicine or a side effect of its use. If such symptoms occur, it is recommended that the treating physician be consulted immediately to assess the need for dose change or discontinuation of therapy.

I encourage you to report the symptoms you experience to your doctor, as well as to report the occurrence of an adverse effect of the preparation. Reporting side effects allows you to increase control over medicines available on the market. We wrote more about how and why to report side effects in the article: 

https://www.gdziepolek.pl/artykuly/jak-i-dlaczego-zglaszac-dzialania-niepozadane

If you need more personalized advice, you can use teleconsultations here:

https://www.gdziepolek.pl/telekonsultacja/

The availability of Efracea in pharmacies in Polish can be checked at the following address:

https://www.gdziepolek.pl/produkty/26312/efracea-kapsulki-o-zmodyfikowanym-uwalnianiu/apteki