Many studies have found that smokers are more susceptible to pericoronitis. Nicotine in cigarettes reduces blood flow. This in turn reduces the ability of the tissues to fight off infection. Also if the blood flow is reduced to the affected area, then antibiotics would not be able to work properly.
Next Steps
Completely avoid smoking not only during the antibiotics course, but also till the time the tissues don't heal completely.
Health Tips
Continuing smoking would make the problem last longer and would not let it resolve faster. Try alternative nicotine fixes if there is a strong urge to smoke.