Doxycycline tablets are tetracycline antibiotic tablets with doxycycline as the main ingredient. It has a good antibacterial effect on a variety of gram-positive bacteria, gram-negative bacteria, and some atypical pathogens (such as chlamydia, mycoplasma, etc.). It is widely used in the treatment of respiratory infections (such as pneumonia, bronchitis), urinary tract infections, skin and soft tissue infections, sexually transmitted diseases (such as gonorrhea, chlamydia infection), etc. It can also be used for malaria prevention. Its mechanism of action is to inhibit the synthesis of bacterial proteins, thereby inhibiting the growth and reproduction of bacteria to achieve the purpose of treating infections. It must be used strictly in accordance with the doctor's advice, in the specified dosage and course of treatment.