Sumycin may increase the sensitivity of the skin to sunlight, and severe burning billigste sted a kjope sumycin may result. Symptoms of Sumycin overdose include nausea, vomiting, and diarrhea. What happens if miss dose? Take the missed dose as soon as you remember. ANTICOAGULANTS-Because the tetracyclines have been shown to depress plasma prothrombin activity, patients who are on anticoagulant therapy may require downward adjustment of their anticoagulant dosage. Do not take any Sumycin 250 mg after the expiration date printed on the bottle. To clear up your infection completely, continue using Sumycin for the full course of treatment even if you feel better in few days.