IF:Pain © PGXL Laboratories

Pain Management - Opioids Problem and Implications 2% to 40% of adults suffer from chronic pain 1 90% of patients in the pain management setting receive opioids 2 Prescriptions for opioids have skyrocketed in recent years 3 178% increase in hydrocodone 3 556% increase in oxycodone 3 Opioid poisoning increased 91.2% between 1992 and % of patients with adverse events from opioids had impaired CYP2D6 metabolism 5 Increased regulatory oversight and guidelines Codeine has pharmacogenetic language in label 1.Statement of Laxmaiah Manchikanti, MD, CEO, American Society of Interventional Pain Physicians Before the Sub- committee On Criminal Justice, Drug Policy, And Human Resources, July 26, 2006, Prescription Drug Abuse: What Is Being Done To Address This Drug Epidemic? 2.Manchikanti L, Damron KS, McManus CD, Barnhill RC. Patterns of illicit drug use and opioid abuse in patients with chronic pain at initial evaluation: A pro- spective, observational study. Pain Physician 2004; 7: Testimony of Nora D. Volkow, M.D., Director, National Institute On Drug Abuse, National Institutes Of Health, U.S. Department Of Health And Human Services, Before The Subcommittee On Criminal Justice, Drug Policy, And Hu- man Resources Committee, July 26, Paulozzi LJ, Budnitz DS, Yongli X. In- creasing deaths from opioid analgesics in the United States. Pharmacoepidemiol Drug Saf 2006; 15: Utilization of Pharmacogenetics and therapeutic drug monitoring for opioid pain management. Pharmacogenomics 2009;10(7):

Pain Management: Opioids Clinical FactEconomic ImplicationRef Response to opioids can very as much as 40 fold among patients. Blood concentrations of opioids does not predict analgesia. Pain medications are involved in 30% of all adverse drug events involve pain medications. Adverse drug events cost an average of $5.6M per hospital. Patients with adverse drug events average 8-12 additional hospital days at cost of $16,000 to $24,000 1,2 80% of patients reporting adverse drug reactions had impaired 2D6 metabolism 3,2 51% of patients taking oral opioids experience at least one adverse event or adverse effect. 4,2 29% of preventable adverse drug events were associated with analgesics Increased length of stay by 2.2 days and costs by $3, Relationships between the measurement of pain using visual score analog and morphine requirements during post operative intravenous morphine titration. Anesthesiology 2003;98(6): Agency for Healthcare Research and Quality. Publication # Utilization of Pharmacogenetics and therapeutic drug monitoring for opioid pain management. Pharmacogenomics 2009;10(7): ACPA Guide to Chronic Pain Medication and Treatment Edition 5.The cost of drug events in hospitalized patients. Journal of the American Medical Association 1997;277: Property of PGxl Laboratories

Biochemical and Physiological Effects of Drugs Pharmacokinetics and Pharmacodynamics Pharmacokinetics What the body does to a drug Think metabolism, bioavailability Converting Pro-Drug to active agent Washing the active agent out of the body Pharmacodynamics What the drug does to the body Think therapeutic, sub-therapeutic or toxic Distribution

Pharmacogenetics in Pain Management Leading pain management drugs are metabolized by genes in the CYP450 Super Family Cytochrome P450 Enzymes Enzymes bound to membranes within a cell (cyto) Contain a heme pigment (chrom and P) Heme pigment absorbs light at a wavelength of 450nm (450) More than 50 enzymes in CYP450 CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5 90% of drugs are metabolized by these 6 enzymes 1,2 1. Wilkinson GR. Drug metabolism and variability among patients in drug response. N Engl J Med. 2005;352:2211– Slaughter RL, Edwards DJ. Recent advances: the cytochrome P450 enzymes. Ann Pharmacother. 1995;29:619–24.

Phenotypes Categories of people with specific CYP450 variants (polymorphisms) Extensive Metabolizer (EM): Normal Genetics Two Good Copies of the genetic code required for metabolism Intermediate Metabolizer (IM): Reduced enzymatic activity 1 Good Copy and 1 Bad Copy of code required for metabolism May render the drug a No Go or require a dose adjustment Poor Metabolizer (PM): Complete lack of enzymatic activity 2 Bad Copies code required for metabolism Usually renders a drug a No Go Ultra Rapid Metabolizer (UM): Higher than average enzymatic activity 2 Bad Copies causing much higher than normal metabolism May render the drug a No Go or require a dose adjustment

Incidence of Variants in the Population Are variants rare or common? GeneEMIMPMUMTotal CYP2D653%35%10%2%47% CYP2C1936%32%4%28%64% CYP2C957%40%3%NA43% CYP3A487%12%1%NA13% CYP3A51%18%81%NA99% OPRM1 Caucasians African Americans Asians Normal 60%80%30% Intermediate 30%19%50% Poor 5%1%20%

Pharmacogenetics in Pain Management Pharmacogenetics is only relevant if the drug is metabolized by a CYP450 enzyme ** Prodrug

Consensus Recommendations Our report will suggest specific actions for these drugs only GenePhenotypeDrugConsensus Based Action Examples CYP2D6Intermediate Metabolizer  35% of the population oxycodoneAvoid hydrocodoneAvoid codeineDose Adjustment nortriptylineDose Adjustment amitriptylineDose Adjustment imipramineDose Adjustment Poor Metabolizer  10% of the population codeineAvoid hydrocodoneAvoid oxycodoneAvoid tramadolAvoid amitriptylineAvoid clomipramineDose Adjustment imipramineDose Adjustment Ultra Rapid Metabolizer  approx 2-6% of Caucasian population  29% of North African and Ethiopian populations  6% of African American populations codeineAvoid hydrocodoneAvoid oxycodoneAvoid tramadolDose Adjustment nortriptylineDose Adjustment imipramineDose Adjustment clomipramineAvoid AmitriptylineAvoid

Consensus Recommendations Our report will suggest specific actions for these drugs only GenePhenotypeDrugConsensus Based Action Examples CYP2C19Intermediate Metabolizer 25% of the population ImipramineDose Adjustment Poor Metabolizer 2% of the population Methadone (active portion) Carisoprodol Possible dose adjustment Avoid, or use with caution Ultra Rapid Metabolizer  28% of the population Carisoprodol OPRM1Poor ResponderActive Opioids (eg, morphine) Dose Adjustment Intermediate ResponderActive OpioidsDose Adjustment

IF:Pain We test and report on Kinetics and Dynamics

Hydrocodone Oxycodone Codeine Tramadol Morphine Hydromorphone Oxymorphone Fentanyl Common Opioids

Poor Metabolizer = decreased metabolic activity Prodrug = lack of efficacy from no active metabolite Active Drug = risk of side effects Ultrarapid Metabolizer = Super-fast metabolic activity Prodrug = risk of side effects from active metabolite Active drug = risk of therapeutic failure

Incorporating PGX into Pain Management What to do with results? – CYP2D6 abnormal results (PM, UM): AVOID prodrugs due to potential lack of efficacy/risk ADRs – CYP2D6 EM or IM results with inhibitor: use caution – OPRM1 G carriers: pts may need higher than average doses PM = decreased metabolic activity Prodrug = lack of efficacy from no active metabolite Active Drug = risk of side effects UM = fast metabolic activity Prodrug = risk of side effects from active metabolite Active drug = risk of therapeutic failure

CODEINE CYP3A4 CYP2D6 Norcodeine Morphine Morphine-6-glucuronide Morphine-3-glucuronide Active opioid effects (OPRM1) Renal Excretion Reynolds KR et al. Clin Lab Med 2008;28:581–598. CYP2D6 PM: inadequate morphine CYP2D6 UM: morphine toxicity Property of PGxl Laboratories

Report **Lack of efficacy due to failure to produce active metabolite; † Increased risk of adverse events due to diminished drug clearance. CYP2D6 Poor Metabolizer (PM): This patient’s genotype is consistent with a lack of CYP2D6 enzymatic activity. PMs are at increased risk of drug-induced side effects due to diminished drug elimination of active drugs or lack of therapeutic effect resulting from failure to generate the active form of the drug, as is the case with pro-drugs. Property of PGxl Laboratories

IF:Pain We test and report on Kinetics and Dynamics

Pharmacogenetics in Opioids In addition to CYP450, we also test for OPRM1 Cytochrome P450 Enzymes Enzymes bound to membranes within a cell (cyto) Contain a heme pigment (chrom and P) Heme pigment absorbs light at a wavelength of 450nm (450) More than 50 enzymes in CYP450 CYP1A2, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5 90% of drugs are metabolized by these 6 enzymes 1,2 1. Wilkinson GR. Drug metabolism and variability among patients in drug response. N Engl J Med. 2005;352:2211– Slaughter RL, Edwards DJ. Recent advances: the cytochrome P450 enzymes. Ann Pharmacother. 1995;29:619– Reynolds 2008; Reyes-Gibby 2007; Klepstad 2004 OPRM1: Mu Opioid Receptor Variant decreases receptor availability 3 May lead to increased dose requirements 3