Is the word antibióticos the same in Brazilian and European Portuguese?

Yes

The spelling, meaning, and grammar of "antibióticos" are identical in both Brazilian and Continental Portuguese. The only difference lies in pronunciation:

• Vowels: In Brazilian Portuguese, vowels are typically more "open" and clearly articulated. In Continental Portuguese, unstressed vowels (such as the "i" in the suffix "-icos") are often "reduced" or more closed, making them sound much shorter or nearly swallowed.
• Sibilants: In most regions of Brazil, the final "s" is pronounced as a soft "s" (like in "sun"). In Portugal, the final "s" is almost always pronounced as a "sh" sound (like in "shoe").

Brazilian Portuguese Examples

1. O médico receitou antibióticos para a infecção. (The doctor prescribed antibiotics for the infection.)
2. Você não pode parar de tomar os antibióticos antes da hora. (You cannot stop taking the antibiotics prematurely.)
3. Eu esqueci de comprar os antibióticos na farmácia. (I forgot to buy the antibiotics at the pharmacy.)
4. O uso de antibióticos deve ser controlado. (The use of antibiotics must be controlled.)
5. Os antibióticos estão fazendo efeito. (The antibiotics are working.)

Continental Portuguese Examples

1. O médico receitou antibióticos para a infeção. (The doctor prescribed antibiotics for the infection.)
2. Não podes deixar de tomar os antibióticos antes do tempo. (You cannot stop taking the antibiotics prematurely.)
3. Esqueci-me de comprar os antibióticos na farmácia. (I forgot to buy the antibiotics at the pharmacy.)
4. O uso de antibióticos deve ser controlado. (The use of antibiotics must be controlled.)
5. Os antibióticos estão a fazer efeito. (The antibiotics are working.)