Global Post-operative Pain Therapeutics Market is segmented By Drug Type (Opioids, NSAIDs, Glucocorticoids, Local Anesthetics, Tricyclic Antidepressants, Antiepileptic drugs, Others), By Route of Administration (Oral, Intravenous, Intramuscular, Others), By Type of Pain (Neuropathic Pain, Nociceptive Pain), By Distribution Channel (Hospital Pharmacies, Retail Pharmacies, Online Pharmacies, E-commerce, Others)