A swelling on the face could be due to an infection resulting from a decayed/damaged tooth. Over the counter painkillers would help relieve the pain, but only to an extent. Kindly visit a dentist soon and get it evaluated properly. No medication, especially antibiotics, can be suggested without examining the patient.
Next Steps
Visit you dentist at the earliest.
Health Tips
Make sure the patient does not apply anything externally on the swelling. No balm, No hot or cold fomentation.
Taking antibiotics without a doctor's prescription can be be harmful. Every specific condition requires a specific medication which can be prescribed by your doctor after complete evaluation only.
Painkillers should be taken only as an emergency measure to control the pain till you visit the dentist.