Do Chinese medicine practitioners also use injections?

Yes, nowadays many Chinese medicine practitioners use a little bit of western medicine to see patients, because western medicine works much faster than Chinese medicine.

There are also some people who don't like to drink Chinese medicine, so there are manufacturers who make the ingredients in Chinese medicine into liquids that can be consumed directly, like Blue Scutellaria Oral Liquid and Banlangen Punch. Some have low gastrointestinal absorption, all then can be hooked up intravenously.