Is it safe to combine the use of medications? Sulovas, Asertin and Venalex ?

The available sources show that there are no pharmacological interactions between the above-mentioned drugs, so there are no contraindications to their concomitant use.
Just remember to keep at least a 20-minute interval between each tablet and medication always with water for complete safety.

Here you can check the availability of the drug with the possibility of reserving it at the pharmacy: 

https://www.gdziepolek.pl/produkty/7639/asertin-100-tabletki-powlekane/apteki

https://www.gdziepolek.pl/produkty/98385/sulovas-kapsulki/apteki

Here you can compare the prices of sample preparations to improve venous circulation and order them with home delivery or collection at the pharmacy:

https://www.gdziepolek.pl/produkty/81738/venalex-kapsulki/apteki

https://www.gdziepolek.pl/produkty/81807/venoruton-forte-tabletki/apteki

https://www.gdziepolek.pl/produkty/23779/diohespan-max-tabletki/apteki

In cities such as Warsaw, Wrocław, Katowice, Kraków, Lublin, Gdańsk, Łódź, Szczecin, Białystok, Poznań and Chorzów, products can be ordered with instant delivery in as little as 1 hour thanks to the Wolt Drive service. Throughout June, delivery with Wolt Drive is free on orders from 99 zł  - check if the service is available in your location:  https://www.gdziepolek.pl/koszyk/szybka-dostawa?src=zf

I am sending you materials that may be helpful:

https://www.gdziepolek.pl/artykuly/leki-na-zylaki

Best regards!