Acute Pain Management in the Elderly

1. Acute Pain Management in the Elderly Cheryl Kaye, PharmD PGY1 Pharmacy Resident University of Arkansas for Medical Sciences

2. Disclosure of Interest • Dr Kaye has signed a document stating that she has NO disclosures.

3. Objectives • Describe acute pain and pharmacokinetic changes that make pain management in the elderly challenging • State the goals for management and treatment options for acute pain in the elderly patient.

4. History of Pain • The word pain is derived from the Latin peone and the Greek poine , meaning “penalty” or “punishment” from the gods. • Aristotle believed pain to be a passion of the soul – a belief that predominated for 2,000 years. • Today we realize that pain is due to a complex array of neural networks in the brain that are acted upon by afferent stimuli, thus producing pain.

5. What is acute pain? • Acute Pain • Limited in duration (<6 weeks) or for duration of injury • Usually nociceptive in nature, although it can be neuropathic • Common causes: surgery, acute illness, trauma, and medical procedures. • Often localized, well described, relieved with conventional analgesic therapy

6. Characteristics of Acute & Chronic Pain Baumann Terry J, Strickland Jennifer M, Herndon Chris M, "Chapter 69. Pain Management" (Chapter). Joseph T. DiPiro, Robert L. Talbert, Gary C. Yee, Gary R. Matzke, Barbara G. Wells, L. Michael Posey: Pharmacotherapy: A Pathophysiologic Approach, 8e: http://www.accesspharmacy.com/content.aspx?aID=7986332.

7. Fears in Pain Treatment • Pharmacokinetic changes • Delirium and Dementia • Polypharmacy • Multiple disease states • Addiction fears • “Opiophobia”

8. Special Considerations in the Elderly • Reporting of pain • Many elderly believe pain is part of growing old and thus underreport • Dementia and Delirium • Reduces the ability to express and localize pain

9. Pharmacokinetic Changes in the Elderly • Absorption • GI: transit time into the small intestine is slowed, but there is no change in overall absorption • Skin: changes in skin (reduced blood flow, thinner skin) may lead to possible increases or decreases in drug absorption

10. Pharmacokinetics • Distribution • Decrease in total body water • Water soluble medications will have a smaller volume of distribution • Decrease in lean muscle mass • Medications that distribute into muscle will have a smaller volume of distribution • Increase in the percentage of body fat • Lipid soluble medications will accumulate • Protein binding – may or may not be decreased • Normal in healthy elderly, malnourished have decreased serum proteins

11. Pharmacokinetics • Metabolism • In the elderly, the liver is small and has decreased blood flow • Drugs with high first pass metabolism will have increased bioavailability • Phase I and II reactions • Phase I: oxidation, reduction, hydrolysis • Decreased in the elderly • Phase II: glucuronidation, acetylation, sulfation • Do not show a significant decrease in the elderly

12. Pharmacokinetics • Elimination • Renal mass and blood flow are reduced, decrease in functioning glomeruli • GRF drops ~ 1% per year for every year past age 20 • Reduced excretion of drugs through the kidneys • Cockcroft-Gault equation is the best validated form of estimating CrCl in pts >75 years and has the most data for drug dosing adjustments. • (x 0.85 for women)

13. Treatment Goals • Prompt & adequate treatment of acute pain • Facilitate recovery from underlying disease or injury • Prevent development of chronic pain • Help the patient resume an acceptable QOL

14. Benefits of Prompt and Adequate Treatment • Relief of suffering • Many pain clinicians believe that swift treatment of pain (both acute and chronic) minimizes time in the hospital and time away from work, while maximizing quality of life • Undertreated pain leads to other problems: reduced QOL, decreased socialization, depression, sleep disturbances, cognitive impairment, malnutrition

15. Treatment Options

16. Non-Pharmacologic Treatment • Physical Therapies: Massage, stretching • Application of Heat or Ice • Physiotherapy: Walking • Transcutaneous Electric Nerve Stimulation

17. Non-Pharmacologic Treatment • Provide Information: Educate patient about what to expect and how it will feel (good for medical procedures • Complementary and Alternative Therapies: Music, aromatherapy, prayer, acupuncture, acupressure, relaxation training, hypnosis • Non-pharmacologic treatment of acute pain should supplement, but not replace, analgesics.

18. Topical Therapy- OTC • Salicylate cream (Aspercreme) • Muscle aches, sprains • Salicylate & menthol (BenGay, Icy Hot) • Muscle aches, bruises, simple backaches, sprains, strains • Capsaicin cream (Capsasin-P, -HP) • Muscle aches, strains,sprains, bruises, cramps

19. Topical Therapy - RX • Diclofenacgel (Voltaren), patch (Flector) • Acute pain due to minor strains, sprains, contusions • Lidocaine ointment (Xylocaine), patch (Lidoderm) • Ointment: minor buns, cuts, abrasions; Patch: postherpetic neuralgia • Capsasin patch (Qutenza ) • Postherpetic neuralgia

20. Non-Opioid Analgesics • Acetaminophen • Recommended first line in elderly patients for mild-moderate pain • 325-650mg every 4-6 hours or 1000mg three or four times a day • Do not exceed 4 gm per day • Malnourished states (fasting, gastroenteritis, alcoholism) increase risk of toxicity • Renal impairment • CrCl 10-50ml/min: administer every 6 hours • CrCl <10ml/min: administer every 8 hours • Hepatic impairment - Use with caution

21. Non-Opioid Analgesics • NSAIDs (OTC) • Ibuprofen 200 mg q 4-6 hrprn; • Maximum 1.2 gm/day • Avoid use in severe hepatic impairment • Avoid use during anuria or oliguria • Naproxen 200 mg q 8-12 hrprn; • May take 400 mg for initial dose; • Maximum 600mg per 24 hours • CrCl <30 mL/min: use is not recommended

22. Non-Opioid Analgesics • NSAIDs – Prescription • Ketorolac • Etodolac • Indomethacin • Ketoprofen • Diclofenac • Piroxicam • Celecoxib • Meloxicam

23. Non-Opioid Analgesics • NSAID Side Effects: • Bleeding – interfere with platelet aggregation • Many elderly are already on warfarin or aspirin • Use with care in surgical pts due to ↑ risk of bleeding • GI toxicity – dyspepsia, ulceration • Administer with food to reduce GI symptoms • Can use PPI, H2 antagonist, misoprostol • Hepatic & Nephrotoxicity(renal vasoconstriction) • Increased cardiac events (MI, stroke) • Increased BP (avgeof 3/2 mmHg, but wide variation) • Exacerbation of CHF (pre-existing and 1st occurrence)

24. Which NSAID to Use? • NSAID choice based on CV and GI risk: • Increased CV risk: larger doses, longer duration, COX-2 selective • Highest risk: diclofenac 100 mg/day, celecoxib 400 mg/day or greater • Lowest risk: appears to be naproxen • Increased GI risk: larger doses and longer-acting products • Highest risk: piroxicamand ketorolac • Lowest risk: appears to be ibuprofen and celecoxib • BUT lower GI risk associated with celecoxib if used > 6 months. Managing NSAID risks. Pharmacist’s Letter/Prescriber’s Letter 2010;26(8):260810. (Full update December 2010; last modified October 2011).

25. Which NSAID To Use? • GI Risk Factors: age > 65, daily ASA, high-dose NSAIDs, prior uncomplicated ulcer • High risk for GI events: ≥ 3 risk factors • Moderate risk for GI events: 1-2 risk factors • Low risk for GI events: 0 risk factors • CV risk factors: HTN (CV morbidity and mortality is directly related to BP), DM, Post-MI, Post-Stroke, CAD Managing NSAID risks. Pharmacist’s Letter/Prescriber’s Letter 2010;26(8):260810. (Full update December 2010; last modified October 2011).

26. Which NSAID to Use? Managing NSAID risks. Pharmacist’s Letter/Prescriber’s Letter 2010;26(8):260810. (Full update December 2010; last modified October 2011).

27. Opioids - Moderate Pain • Codeine • Renal Impairment • CrCl 10-50 mL/min: use 75% of normal dose • CrCl <10 mL/min: use 50% of normal dose • Hepatic Impairment • Dosing adjustments probably necessary, initiate at lower dose • Weak Analgesic – use with NSAIDs, ASA, APAP

28. Opioids - Moderate Pain • Tramadol • Use with caution in pts >65 years • Do not exceed 300mg/day in pts >75 years • Inhibits serotonin and norepinephrine reuptake • Serotonin syndrome a concern, especially in pts on other serotonergic drugs • Seizure risk in pts with history of seizure or on meds that lower the seizure threshold • CrCl <30 ml/min: 50-100 mg IR q12h (max 200mg/day) • The ER preparation should not be used • Cirrhosis: 50 mg IR q12h • ER preparation should not be used in sever hepatic dysfunction

29. Opioids - Moderate/Severe Pain • Hydrocodone • Only available as a combination product with APAP, NSAIDs • Remember to counsel patient against using other external sources of acetaminophen or NSAIDs • Make sure patient understands acetaminophen, Tylenol, and APAP are the same thing

30. Opioids - Moderate/Severe Pain • Oxycodone • Hepatic impairment: use with caution • CrCl<60 mL/min: Serum concentrations ↑ ~50% • Hepatic Impairment: ↓ the dose of CR tabs to 1/3-1/2 usual dosage • Most effective when used with NSAIDs, ASA, APAP

31. Opioids – Severe Pain • Morphine • Considered the drug of choice by many physicians for severe pain • DOC for acute MI • New opioid and non-opioid compounds are compared against morphine as the standard for efficacy and SE.

32. Opioids – Severe Pain • Morphine • Metabolized to morphine-6 glucuronide(M6G) and morphine-3 glucuronide (M3G), which are renally cleared • M6G contributes to analgesia, M3G contributes to SE if accumulation occurs • Renal Impairment: • CrCl 10-50 mL/min: use 75% of normal dose • CrCl <10 mL/min: use 50% of normal dose • Hepatic Impairment: no change in mild disease, ↓ dose in cirrhosis

33. Opioids – Severe Pain • Hydromorphone • More potent than morphine • Some clinicians believe it to have less pruritis compared to other opioids, but there has been no conclusive research.

34. Opioids – Severe Pain • Hydromorphone • Moderate Renal Impairment: low dose, close monitoring • Severe Renal Impairment: consider alternate drug • Moderate-Severe Hepatic Impairment: low dose, close monitoring

35. Opioids – Severe Pain • Fentanyl • Transdermal patch not for acute pain (12-24 h onset) • Iontophoretic patient controlled transdermal system for use in acute postoperative pain (IONSYS)

36. Opioids – Severe Pain • Demerol • NOT RECOMMENDED IN THE ELDERLY (American Pain Society 2008 and ISMP 2007) • Normeperidine (metabolite) can cause seizures, tremors, myoclonus • DO NOT USE IN RENAL FAILURE • Normeperidine is renally cleared, so the risk for toxicity is greatest in those with renal failure.

37. Opioid Side Effects • CONSTIPATION! • Remember to use an appropriate bowel regimen if using opioids! • Stool softeners and stimulant laxatives ATC, along with hydration and physical activity • Constipation symptoms • Anorexia • Nausea • Delirium • Supraventricular tachyarrhythmias

38. Opioid Side Effects • Dysphoria • Lethargy • Drowsiness • Inability to Concentrate • Apathy • N/V • Respiratory Suppression • Histamine release – pruritus An electronic opioid dose calculator can be downloaded at: http://www.agencymeddirectors.wa.gov/guidelines.asp

39. Adjuvant Treatments • Tricyclics – good for neuropathic pain • Amitriptyline, imipramine, doxepin, clomipiramine, desipramine • Anticholinergic SE • CI in pts with significant cardiac arrhythmias, bladder outflow obstruction, prostatic hypertrophy and narrow-angle glaucoma • Use with extreme caution in elderly • Start low and go slow, giving dose at bedtime

40. Adjuvant Treatments • Anticonvulsants – good for neuropathic pain • Gabapentin, pregabalin, carbamazepine • Titrate off slowly to prevent seizures • Antispasmodics • These agents are on the Beers List

41. Route of Administration • Route of Administration • Depends the needs of each individual patient • Oral route preferred, whenever possible • Alternative routes of therapy preferred if pt in severe acute pain or unable to tolerate PO,. Bromley Lesley, BrandnerBrigitta. “Chapter 11. Acute pain in the elderly” Acute Pain. Oxford University Press, 2010.

42. Route of Administration • Postoperative Pain • Continuous IV and SQ opioid administration are effective, but the probability for unwanted SE is high. • Patient Controlled Analgesia (PCA) is an alternative. Compared to prnopioid dosing, PCA yields better pain control, improved pt satisfaction, and relatively few differences in SE. Bromley Lesley, BrandnerBrigitta. “Chapter 11. Acute pain in the elderly” Acute Pain. Oxford University Press, 2010.

43. Analgesic Ladder • Mild to Moderate (0-3), non-opioid, NSAID, ASA, APAP (+/- adjuvant) • Moderate to Severe (4-6), add a weak opioid, codeine or hydrocodone, available in combo with non-opioids. (+/- adjuvant) • Severe Pain (7-10), replace weak opioid with strong opioid (morphine, oxycodone, others) (+/- adjuvant)

44. Treatment Algorithm

45. Case 1 • CC: “I stepped in a hole and fell down while tending to my garden and now my right ankle hurts when I walk.” • HPI: MM is a 69 y/o WF brought after falling to the ER by her family. She lives alone and is very active. • PMH: HTN, HPLD, DM Type II • Allergies: NKDA • MPTA: MVI daily , lisinopril 5 mg daily, simvastatin 5 mg daily, metformin 1000mg BID, ASA 81 mg daily

46. Case 1 • PE: Ht: 5’6”, Wt: 60 kg, BP: 145/85, HR: 87, RR: 12, Pain Score: 5.5, erythema, warmth, swelling, bruising noted on right ankle • Labs: WNL , SCr: 1.2, (CrCl~42mL/min) • X-ray: shows no evidence of fracture • Assessment: sprained ankle • What is your plan to treat her pain?

47. Case 2 • HPI: AB is a 65 y/o WM with h/o ulcerative colitis x 15 years. Conventional medications have stopped working for him, and he has decided undergo BCIR surgery (appliance-free intra-abdominal ileostomy). • PMH: HTN, MI x 5 yrs ago, HPLD, arthritis, mild hepatic impairment • MPTA: lisinopril 20 mg daily, ASA 81 mg daily, metoprolol 50 mg BID, simvastatin 20 mg daily, Aspercreme QID to hands

48. Case 2 • Labs: WNL (CrCl~60mL/min) • Assessment: ulcerative colitis, admit for colectomy • Devise a post-surgery treatment plan for his pain.

49. Summary • Pain tends to be undertreated in the elderly • Although more complicated, pain treatment in the elderly is still vitally important! • Be aware of drug therapy and disease states that may alter treatment choices. • Start low, go slow and increase dose as needed • Stay on the lowest dose that effectively treats pain for the shortest duration necessary • Assess and reassess pain frequently

50. Questions?