Since your symptoms are related to an allergy, antibiotics like Cefolac XL (Cefixime and Cloxacillin) will not help, as they only treat bacterial infections. You should stop taking the antibiotic and consult your doctor to determine the cause. Your doctor may recommend antihistamines, decongestants, nasal corticosteroid sprays, or other allergy treatments. Simple measures such as staying hydrated, using a humidifier, avoiding allergens (dust, pollen, smoke), and saline nasal rinses may also help.