Pain Management

1. Pain Management Robert V. Brody, M.D. Attending Physician Medicine, Pain, and Palliative Care Services, and Chief, Pain Consultation Clinic, San Francisco General Hospital Medical Director, Health at Home, San Francisco Department of Public Health Clinical Professor of Medicine and Family & Community Medicine, UCSF

2. What is Pain? PAIN:an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage. International Association for the Study of Pain Not just the unpleasant sensation, not just the perception of the sensation, but also the emotional reaction to or experience of the perceived sensation. Pain is therefore always SUBJECTIVE

3. Framework for Pain Management: • Gate Control Theory of Pain • Pain is an interaction between excitatory and inhibitory pathways: • Excitatory “opens gates” = increases in pain • Inhibitory “closes gates” = decreases in pain • These pain pathways integrate information from: • Sensory – physiological components • Cognitive – evaluative components • Motivational – affective components

4. Assessment • History, including medical, psychsocial, and addiction issues and: • Location & distribution • Duration & periodicity • Quality • Pain scale 0-10 • Associated signs & symptoms • What makes it worse or better • Previous treatments and outcomes • Effect on function • Patient goals and expectations • Physical examination

5. 0 2 4 6 8 10

7. Take apart the pain complaint: What kind of pain? • somatic? • inflammation? • muscle spasm? • visceral? • ischemic? • crampy? • neuropathic? Psychological issues? • Substance use? • sleeplessness? nightmares? pain? • anxiety / depression? • PTSD? • history of sexual / physical / emotional abuse?

8. Non-Pharmacologic pain management • Physical therapy / exercise / stretching / yoga • Massage / heat and cold • Acupuncture • Biofeedback / neurofeedback • Transcutaneous electrical nerve stimulation TENS • Cognitive behavioral therapy • Therapeutic provider-patient relationship.

9. Neuropathic Pain • Peripheral neuropathy, nerve compression, phantom limb, radiculopathy, herpetic neuralgia, tic douloureaux • Listen for the adjectives: sharp, shooting, buzzing, electric, radiating. Not aching.

10. Anti-neuropathic Agents • tricyclic agents - desipramine, nortriptyline, imipramine, amitrityline • other antidepressants - duloxetine, venlafaxine, milnacipran, SSRI’s, bupropion, mirtazapine • anti-epileptics - carbamazepine, gabapentin, topiramate, lamotrigine pregabalin, tiagabine, zonisamide • lidocaine, mexilitene, (flecainide) • baclofen • capsaicin • conventional analgesics

11. Anti-spasmodics • baclofen • carisoprodol • tizanidine • dantrolene • cyclobenzaprine • methocarbamol

12. Analgesic Ladder Step 2Step 3 CodeineMorphine Hydrocodone (Diacetylmorphine) Step 1 Meperidine Hydromorphone Butorphanol Oxycodone Aspirin Pentazocine Oxymorphone Acetaminophen Tramadol Fentanyl NSAID’s Tapentadol Methadone Buprenorphine Levorphanol

15. Some principles of opiate use • Increase opioid dosage by percentages – 10%, 15%, 20% - not milligrams. • USE THE GI TRACT • Methadone is great, but… • One long acting, one short acting, plus methadone for withdrawal • Patient controlled analgesia - basal rate

16. Adverse Effects of Opiates • Constipation • Almost universal in patients taking opiates and should be anticipated • The one effect to which patients do not become tolerant • Prophylactic treatment better than prn. • Stool softeners and propulsantsmay be useful, as is sorbitol or polyethylene glycol. • Avoid bulk agents • Nausea • Common with opiates, and often caused by constipation. Useful agents: • antihistamines • butyrophenones (haloperidol, droperidol) • phenothiazines (prochlorperazine, promethazine) • scopalamine • rarely, benzodiazepines

17. Adverse Effects of Opiates • Itching • May respond to antihistamines, and is self-limited when due to mast cell degranulation. True allergic reactions do occur (hives). • Sedation • May be temporary with initiation of therapy. If persistent: • Try reducing the dose of medication • Increase the interval between doses • Switch agents • Add caffeine, or rarely dextroamphetamine or methylphenidate • Respiratory depression • Rare in chronic opioid therapy • Observe patient closely • Physical stimulation may be sufficient • If naloxone required, dilute 0.4mg ampule in 10cc NS and administer 0.5ml IV push q 2 minutes. Titrate dose to avoid withdrawal, seizures, severe pain. • Decreased libido, fertility with long term use.

18. Mental Health Issues and Pain • Anxiety / depression • Post traumatic stress • Substance abuse • Sexual / physical / emotional abuse

19. Tolerance • APS: State of adaptation in which exposure to a drug induces changes that result in a diminution of one or more of the drug’s effects over time • Refers to the need for increasing amounts of the substance to achieve the desired effect, or markedly diminished effects with continued use of the same (usual) amount of the substance. American Pain Society, 2001

20. Physical Dependence • APS: State of adaptation that is manifested by a drug class specific withdrawal syndrome that can be produced by abrupt cessation, rapid dose reduction, decreasing blood level of the drug, and/or administration of an antagonist. • Occurs when, after a period of continuous use, abrupt discontinuation of an agent causes physical systems (withdrawal or abstinence syndrome) • Is a common feature of opioids, corticosteroids, barbiturates, benzodiazepines, antihypertensive and other agents • Is easily managed by gradually tapering the drug if it is no longer needed American Pain Society, 2001

21. Drug Abuse • The inappropriate use of a medication for a non-medical purpose.

22. Addiction • APS: Addiction is a primary, chronic, neurobiological disease, with genetic, psychosocial, and environmental factors influencing its development and manifestations. It is characterized by behaviors that include: • impaired control over drug use, • compulsive use, • continued use despite harm, and • craving • There is no concensus about the percentage of patients prescirbed opioids for pain who later develop a substance use disorder or addiction. Patients with a history of SUD are at risk of relapse. American Pain Society, 2001

23. Pseudoaddiction • Pseudoaddict: • Patient with a chronic painful condition who requires opiates to function. • May exhibit behaviors which providers label as manipulative, obsessive or drug seeking in order to find sufficient relief from pain to fully participate in life • These behaviors stop promptly after adequate analgesia is provided

24. Sceening for Substance Use Disorder • Have you ever tried to stop using or cut down? • Has your family or anyone else complained about or discouraged your use? • Have you ever had trouble with driving while under the influence? • Did you ever get into trouble or have difficulty at work or school due to your use? • Have you ever been injured while under the influence?

25. Urine Toxicology • Know your laboratory • Approximate duration of detectability of drugs in urine by commonly used screening tests: • Amphetamines 2-4 days • Barbiturates 3 days • Phenobarbital 2 weeks or longer • Cannabinoids Infrequent user: up to 10 days Chronic user: 30 days or longer • Cocaine metabolite 2-3 days • Methadone 2-4 days • Other opiates 2-3 days • Phencyclidine (PCP) 3-8 days • Confirmatory tests: • Gas liquid chromatography with or without mass spectrometry • High performance liquid chromatography • Beating the test: • Substitution • Adulteration with chemicals • Dilution – Substance Abuse and Mental Health Services Administration uses a cut off of specific gravity of 1.003 and urine creatinine concentration of 40 mg/dl

29. Opportunities for Improvement in Your Pain Practice • Believe patient’s report of pain. • Ascertain and treat the cause of pain. • Prevention of pain is better than treatment • Take the pain apart. • Diagnose and treat psychiatric disorders in your pain patients. • Pay attention to sleep disturbance. • Abolish PTSD nightmares with alpha blocking agents like prazosin. • Cognitive behavioral therapy changes lives.

30. Opportunities for Improvement in Your Pain Practice • Substance use is common – order a Utox. • Cocaine is a marker for diversion. • Include non-pharmacologic management approaches. • Recognize neuropathic pain and spasm and treat specifically • Individualize the dosing regimen - the right dose of medication is the dose that works, i.e. improves function. • Titrate the dose of your medication to effect or undesirable side effects • Use the GI tract.

31. Opportunities for Improvement in Your Pain Practice • Understand how to use an equianalgesic table. • Use methadone cautiously. • Limit number of opiates – one long acting, one short acting for breakthrough, plus methadone for opioid use disorder • Pain is a quality of care issue. Seek help from others with more experience.

32. Take apart the pain complaint: What kind of pain? • somatic? • inflammation? • muscle spasm? • visceral? • ischemic? • crampy? • neuropathic? Psychological issues? • Substance use? • sleeplessness? nightmares? pain? • anxiety / depression? • PTSD? • history of sexual / physical / emotional abuse?

33. 55 y/o man remote h/o IVDU p/w back pain, LE weakness, found to have osteomyelitis, diskitis, epidural abscess T12-L3, s/p laminectomy, corpectomy, spinal fusion, complicated by E. coli bacteremia • Labs: WBC 18.4, H/H 7.8/25, plts 424, Na 123, K 3.9, Cl 91, CO2 29, BUN 18, Cr 0.71, glu 100 • Current meds: APAP prn, ascorbic acid 500mg BID, CaCo4 prn, ceftriaxone 2gm q12h, docusate 250mg bid, enoxaparin 40mg, ferrous sulfate 325mg, hydromorphone 1mg IV q2h prn, oxycodone 10mg q4h prn, lansoprazole 30mg, rifampin 300mg bid, senna nightly, silvadene, thaiamine 100mg, vancomycin 750mg q12h, Vit A, zinc • S: “the pain starts in my back and travels to my feel, its very intense, sharp at time, dull at time, its tight in my lower back, my shoulders are achy and sore, I’ve had a bad rotator cuff for years. I smoke weed every day to relax and for my arthiritis pain, I don’t sleep very well, I have nightmares now and then, about my dad and family and how I was treated. I want off the shots – I saw my dad die with my stepmom giving him shots of morphhine and a drip, that scares me.”

34. O: appears in acute discomfort, distress, anxious, tearful • patient has received 9 doses IV hydromorphone + 1 dose oxycodone per 24hrs • A/P • c/o acute somatic and neuropathic pain, • chronic somatic pain, spasms, endorses anxiety, mentions use of cannabis for pain and to relax, insomnia due to pain and anxiety, nightmares of childhood abuse, requesting off IV opioids, • willing to try anti-neuropathic and anti-spasm agents, trial of SNRI warranted once hyponatremia corrected. • Therefore would recommend: • MSContin 30mg po q8hr • Gabapentin 300mg q8h for neuropathic pain • Baclofen 5mg po q12hr for spasms • Change oxycodone to 10mg po q2hr prn breakthrough pain • Change hydromorphone to 0.6mg IV q6hr prn severe pain if oral pain meds ineffective