doxycycline hyclate 100mg tablets is a broad-spectrum antibiotic primarily used to treat bacterial infections. It is effective against a wide range of bacteria, including those causing respiratory tract infections, urinary tract infections, skin infections, sexually transmitted infections such as chlamydia and gonorrhea, as well as certain types of pneumonia, Lyme disease, and acne. However, it is not effective against viral infections such as the common cold or flu.

Respiratory tract infections: Doxycycline is commonly prescribed for bacterial infections affecting the respiratory tract, including sinusitis, bronchitis, and pneumonia caused by susceptible bacteria.

Urinary tract infections (UTIs): It can be used to treat uncomplicated UTIs caused by susceptible bacteria, such as Escherichia coli.

Skin infections: Doxycycline is effective against certain types of skin infections, including acne vulgaris and infections caused by bacteria such as Staphylococcus aureus and Streptococcus pyogenes.