Propylthiouracil is a thiourea antithyroid drug that mainly inhibits the synthesis of thyroxine. Its mechanism of action is to inhibit the oxidation of iodide taken into the thyroid gland and the coupling of tyrosine by inhibiting thyroid endoperoxidase, thereby hindering the synthesis of thyroid hormone (T4) and triiodothyronine. In addition, propylthiouracil also inhibits the deiodination of T4 in peripheral tissues to produce T3.

The antipyretic and analgesic effects are faster and stronger than those of aminopyrine.

Broad-spectrum antiviral drug. It has the effect of inhibiting the growth of many viruses such as respiratory syncytial virus, influenza virus, hepatitis A virus, adenovirus, etc. in vitro, and its mechanism is not fully understood. This product does not change the adsorption, invasion and uncoating of viruses, nor does it induce the production of interferon. After entering the virus-infected cells, the drug is rapidly phosphorylated, and its product acts as a competitive inhibitor of viral synthase, inhibiting inosine monophosphate dehydrogenase, influenza virus RNA polymerase and mRNA guanosine transferase, thereby causing a decrease in intracellular guanosine triphosphate, impairing viral RNA and protein synthesis, and inhibiting viral replication and transmission. It may also have an immune effect and neutralizing antibody effect on respiratory syncytial virus.

Fluoroquinolone antibiotics have a broad-spectrum antibacterial effect, especially against aerobic Gram-negative bacteria. They act on the A subunit of bacterial DNA helicase, inhibit DNA synthesis and replication, and cause bacterial death. They have good antibacterial effects on most bacteria of the Enterobacteriaceae family, penicillin-resistant Neisseria gonorrhoeae, Haemophilus influenzae, and Moraxella catarrhalis.

This product can inhibit viral DNA and RNA polymerase, thereby inhibiting viral reproduction. On human embryonic kidney cells, 1% concentration has a significant inhibitory effect on DNA viruses (adenovirus, herpes virus) and RNA viruses (echovirus), and has an inhibitory effect on all stages of the viral proliferation cycle. It has no direct effect on free viral particles.