One of my kids was so stubborn when she was younger, that it was impossible to administer any medication to her orally. Whenever she needed antibiotics, we opted for a shot administered by the doctor. Was a pleasure, only one dose (or sometimes two IIRC) and that was it!
At the time I asked the Dr. why they don't offer it to more people, as it is so much easier and more effective, and was told that most people would rather take an oral medication regimen for 10 days than needle into them one time.