Possible Side Effects Doxycycline
Check with your doctor if any of these most common side effects persist or become bothersome:* loss of appetite; nausea; sensitivity to sunlight; vomiting.Seek medical attention right away if any of these severe side effects occur: * severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); bloody stools; dark urine; decreased urination; fever, chills, or sore throat; severe diarrhea; severe or persistent headache; stomach pain or cramps; throat irritation; trouble swallowing; unusual bruising or bleeding; unusual tiredness; vaginal irritation or discharge; vision changes; yellowing of the skin or eyes.

Drug Class and Mechanism Doxycycline
Doxycycline is a tetracycline antibiotic. It works by slowing the growth of bacteria. Slowing bacteria growth allows the body's immune system to destroy the bacteria.

More InformationDoxycycline here
Doxycycline is to be used only by the patient for whom it is prescribed. Do not share it with other people. If your symptoms do not improve or if they become worse, check with your doctor.