Whether combining antibiotics with alcohol will cause adverse effects depends on the type of antibiotic you are taking.
For the vast majority of antibiotics, alcohol generally does not reduce their effectiveness. However, both antibiotics and alcohol can cause similar side effects, such as stomach upset, dizziness, and drowsiness. Therefore, taking them together may increase these side effects.
A few antibiotics, such as metronidazole, tinidazole, and co-trimoxazole, should not be taken with alcohol as this may cause more severe side effects. Even a small amount of alcohol during the medication period can cause discomfort such as flushing, headache, nausea, vomiting, rapid heart rate, and shortness of breath.
In rarer cases, alcohol may reduce the effectiveness of certain antibiotics (such as doxycycline), meaning you may need to take a larger dose to achieve the same effect if you consume alcohol simultaneously.
It is also worth noting that alcohol can reduce your energy levels and prolong recovery time. Therefore, whether or not it affects the antibiotics, it is best to avoid alcohol while sick until your body recovers.