Sinus Decongestant Why Do Most Sinus/decongestant Medicines Or Prescription Painkillers Also Include A Dosage Of Acetaminophen Or?

Why do most sinus/decongestant medicines or prescription painkillers also include a dosage of acetaminophen or? - sinus decongestant

For example, hydrocodone is always a dose of paracetamol. Like most drugs without a sinus. Analgesics such as paracetamol and iburprofin seem to do anything for me and I hate to take additional medication, do not really need.