I have finished my full course of antibiotic 4 hours before so can n i drink alcohol?

Generally it's ok: Whilst many drugs should not be taken with alcohol antibiotics are not usually affected to a significant degree.

Depends on…: The antibiotic: some like Flagyl (metronidazole) can interact with alcohol & cause marked nausea & vomiting. Bactrim (sulfamethoxazole and trimethoprim) alone can cause nausea/vomiting even without alcohol. No drug interactions r listed for bactrim, (sulfamethoxazole and trimethoprim) amoxicillin, & alcohol, but it's never a good idea to mix alcohol with meds. Bactrim (sulfamethoxazole and trimethoprim) & alcohol both affect the liver. Best to wait until you've finished antibiotics before drinking.