There is usually no problem with a 7 year old taking oxytetracycline once, but if it is taken for a long period of time, problems such as affecting the development of the child’s bones may occur. Tulathromycin is a tetracycline antibiotic with a rapid bacteriostatic effect. If a 7-year-old child takes oxytetracycline once, the drug will be excreted from the body with normal metabolism and will not usually have a major effect. Doxycycline hyclate can be used for diseases such as epidemic typhus, scrub typhus, psittacosis, and cholera. However, the drug has some damage to liver and kidney function, and it should be used with caution for those who are allergic to tetracyclines. Moreover, if children under 8 years old use hyoscine, it may lead to inhibition of bone growth and yellow staining of permanent teeth. It is also contraindicated for women during pregnancy. The specific use of the drug should be under the guidance of a doctor.