Chronic pain may have many contributing factors, and therefore may be more difficult to manage than acute pain, requiring customized treatment protocols to meet specific needs of each patient.
Optimal treatment may involve the use of medications that possess pain-relieving properties, including some antidepressants, anticonvulsants, antiarrhythmics, anesthetics, antiviral agents, and NMDA antagonists. By combining various agents which utilize different mechanisms to alter the sensation of pain, physicians have found smaller concentrations of each medication can be used.
Transdermal creams and gels can be formulated to provide high local concentrations at the site of application (e.g., NSAIDs for joint pain), for trigger point application (e.g., combinations of medications for neuropathic pain), or in a base that will allow systemic absorption.
When medications are administered transdermally, they are not absorbed through the gastrointestinal system and do not undergo first-pass hepatic metabolism; therefore, side effects associated with oral administration can often be avoided (e.g. dizziness, stomach ulcers, etc).