Hello Dear Thanks for your query. First of all be relaxed, I will be most happy if I could help you out so no need to worry much. I have gone through your query thoroughly. First of all I would like to tell you that in most of the dental problems medicines play role as a supplemental aid along with the treatment. Source of infection which is deep inside the tooth must be removed to get complete cure. So I advice you to get an appointment with the dentist as soon as possible so that he/she can start the needful treatment. Most probably a Root Canal Treatment will cure and save the tooth. Now coming towards FACTIVE (Gemifloxacin mesylate). It is not a drug which is routinly used in this condition since the bacteria which is commonly associated with the dental abscess are not much sensitive to this medicine. Instead you can take Augmentin-625/Megamox-CV 625/Tresmox-CV 625 twice daily for 3 days till you get appointment with the dentist. Usually this medicine doesnt slow down the gut. You can take over the counter anti-inflammatory tablet for example ibuprofen 1 tablet thrice daily for 3 days. • Please consult your operating doctor before starting the medicine. • Do not apply any type of pressure or hot packs on the affected side, Instead you can use a cold pack. • Try not to sleep from the affected side for few days. Hope this will help you. If there is any more query or question regarding this in your mind, you are always welcome. Take Care Regards