All that’s needed to make antibiotics is alcohol. The best way to get some is to win the Grand Bout, which the Senku and his kingdom will also need to do in order to keep Magma away from Ruri and give her the drug.
The sacred rules of the 
Grand Bout are immutable.
.قوانين النزال الكبير المقدّسة ثابتة
Die Regeln des heiligen Großen Wettstreits
sind unveränderlich.
Sono le regole di questo sacro torneo 
e non si possono cambiare.
As regras sagradas da Grande
Luta não podem ser alteradas.