Pain Management Part 2 Use of Adjuvants John Mulder, MD, FAAHPM Vice President of Medical Services Faith Hospice Director, GR MEP Palliative Medicine Fellowship Program Coanalgesic Drugs (Adjuvant Therapy) Definition: Drugs which enhance analgesic efficacy of opioids, treat concurrent symptoms that exacerbate pain, or produce independent analgesia for specific types of pain. • Early use optimizes comfort and function by preventing or reducing side effects of higher doses of opioids Coanalgesic Drugs (Adjuvant Therapy) Most • • • Most • • • • amenable cancer pain syndromes Bone metastases Neuropathic pain Visceral distention commonly used coanalgesic drugs NSAIDs Corticosteroids Antidepressants Anticonvulsants Bone Metastases - Adjuvants • NSAIDs • Steroids • Decadron 4mg BID, titrate • Bisphosphonates • Zometa, Aredia • Radioisotopes Neuropatic Pain – Adjuvants • Tricyclic antidepressants • Anticonvulsants • Steroids Alternative/Adjuvant Medications • NSAIDs • Antidepressants • TCA - Elavil, gold standard; desipramine • SSRI - Paxil only one shown effective thus far; Serzone, Effexor promising • Psychostimulants - dietary caffeine, Ritalin, amphetamines Alternative/Adjuvant Medications • Neuroleptics • Benzodiazapines (watch for sedation) • Anticonvulsants - especially for neurogenic pain (Neurontin) • Baclofen Alternative/Adjuvant Medications • Steroids - high dose, short term/low-dose, long term • Antihistamines (Benedryl, Vistaril) • Alpha-2-adrenergic stimulants (Clonidine) • Cannabanoids Alternative/Adjuvant Medications • Capsaicin • Colchicine • Thalidomide • Ketamine • Lidocaine • Dextromethorphan - (no guaifenesin or alcohol) - 30 mg BID - 1 g/d (400 - 600 mg/d usual ) Narcotic Resistant Pains • Headaches • Muscle Spasm • Tenesmoid (Bowel / Bladder) • Incident to movement • Decubitus • Deafferentation Deafferention Pain • Type I Complex Regional Pain Syndrome A syndrome characterized by severe burning pain in an extremity accompanied by sudomotor, vasomotor, and trophic changes in bone without an associated specific nerve injury. ... • Complex Regional Pain Syndromes Conditions characterized by pain involving an extremity or other body region, HYPERESTHESIA, and localized autonomic dysfunction following injury to soft tissue or nerve. The pain ... • Reflex Sympathetic Dystrophy Syndrome A syndrome characterized by severe burning pain in an extremity accompanied by sudomotor, vasomotor, and trophic changes in bone without an associated specific nerve injury. ... Non-pharmacologic Interventions • OMM • Acupuncture • Acupressure • Massage Therapy • Music Therapy • Hypnosis • Relaxation Unwarranted / Exaggerated Fears • Respiratory Depression • Addiction • Rapid Tolerance • Regulatory Reprisal Opiate Side Effects: Constipation – Most common side effect - expected – Mediated spinally and in GI tract – Decreased peristalsis & decreased intestinal secretions – Tolerance does not readily occur – Treat with peristaltic agent and softeners prophylactically Opiate Side Effects: Pruritis – – – – Caused by opioid induced histamine release Tolerance generally develops quickly Difficult cases may require a change in opioid Usually treated with transient use of antihistamines Opiate Side Effects: Somnolence / Sedation – Common, but tolerance typically develops within a few days – Sedation varies with opioid and dosing schedule – Additive effects with other cerebral depressants – Decrease or discontinue other cerebral depressants – Concurrent use of Dextroamphetamine or Methylphenidate is helpful, but tachyphylaxis is common Opiate Side Effects: Hallucinations / Confusion – Less common, but may occur especially in older patients – Often an indication of excess dosing – Try dose reduction or different opioid Opiate Side Effects: Nausea / Vomiting – Occurs in 50 – 65% of patients on oral morphine – Varies with drug and route – Usually easy to control, occasionally severe and difficult to control Opiate Side Effects: Urinary Retention – Opioids increase smooth muscle tone (sphincter) – May also cause bladder spasms – Try changing opioids or insertion of catheter Opiate Side Effects: Myoclonus – Can occur with all opioids – Typically due to high doses and/or dehydration – Long half-life metabolites are typically implicated – Reduce dose, change opioids, change routes and/or hydrate patient Opiate Side Effects: Respiratory Depression – Cause of death in opioid overdose – Tolerance develops rapidly – Rarely a concern with appropriate dose escalations – If accidental overdose occurs in a patient chronically receiving opioids, dilute Naloxone 1:10 and titrate very carefully to reverse respiratory depression without precipitating withdrawal or reversing analgesia