The earlier treatment is started, the better the results. Antibiotics such as tetracyclines within the first 4 days are effective in shortening the illness. Sometimes leptospires persist in urine for a long time, even with correct treatment. It is preferable to give doxycycline 200 mg per day for 1 week. If there is vomiting IV penicillin is used. Ampicillin is also active against leptospires. Chloramphenicol, on the other hand, is not. Symptomatic and supportive therapy is very important.