Doxycycline belongs to a group of medicines called tetracycline antibiotics. It is also known as a broadspectrum antibiotic and may be used to treat a wide range of infections caused by bacteria, these include: - respiratory tract infections - urinary tract infections - sexually transmitted diseases - skin infections such as acne - infections of the eye - rickettsial infections such as Q fever or tick fever - other infections such as malaria, cholera, brucellosis, leptospirosis, psittacosis and fevers caused by lice or ticks. - or prevent: - travellers diarrhoea, scrub typhus and leptospirosis.