Copyright PGXL Laboratories, Louisville KY All materials herein are the exclusive property of PGXL Laboratories PGX Applications in Pain Management Kristen K. Reynolds, PhD VP Laboratory Operations

Panels* Core: CYP2D6 CYP2C9 CYP2C19 CYP3A4 CYP3A5 CYP1A2 Panel Add-Ons: OPRM1 (opioids) SLC6A4 (SSRIs) *All genes always orderable a la carte

GenericBrandMetabolic Route AlfentanilAlfentaCYP3A4/CYP3A5 Carisoprodol**SomaCYP2C19 CelecoxibCelebrexCYP2C9 Codeine**Various brandsCYP2D6 CyclobenzaprineFlexarilCYP1A2, CYP3A4/CYP3A5 FentanylActiq, DuragesicCYP3A4/CYP3A5 Hydrocodone**Lortab, VicodinCYP2D6 HydromorphoneDilaudidUGT2B7 + IbuprofenAdvil, MotrinCYP2C9 LidocaineVarious brandsCYP1A2 MethadoneVarious brandsCYP2C19, CYP2B6 + MorphineVarious brandsUGT2B7 + NaproxenAleveCYP2C9 Oxycodone**Oxycontin, PercocetCYP2D6, CYP3A4/5 OxymorphoneOpanaUGT2B7 + RopivicaineVarious brandsCYP1A2 TizanidineZanaflexCYP1A2 Tramadol**Ultram, variousCYP2D6 ZolmipitranZomigCYP1A2 **prodrug; + test not yet available Common pain medications with PGXL tests

Opioids

Pharmacokinetic Gene Metabolism Pharmacodynamic Gene Clinical Effect

CYP2D6 - Opioids Hydrocodone Oxycodone Codeine Propoxyphene Tramadol etc…

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

Decreased drug metabolism = lack of efficacy – Poor pain control – Mis-interpretation of drug seeking behavior Ultra-rapid drug metabolism = possible side effects – Over-production of active compound – Mis-interpretation of over-compliance – Possible lower doses required Effects of CYP2D6

FDA Drug Safety Codeine use in certain children after tonsillectomy and/or adenoidectomy may lead to rare, but life-threatening adverse events or death 3 deaths reported in children (2-5yo) who received codeine after undergoing tonsillectomy and/or adenoidectomy for obstructive sleep apnea 3 deaths in children who were CYP2D6 UMs All children received typical codeine doses Morphine toxicity signs developed within 1-2 days after starting codeine Supratherpeutic post-mortem morphine concentrations in the 3 death cases Morphine Overdose from Codeine

FDA recommendations for Physicians: Use the lowest effective codeine dose for the shortest period of time on an as-needed basis (i.e., not scheduled around the clock) Counsel parents: – how to recognize the signs of morphine toxicity – Advise them to stop giving the child codeine – Seek medical attention immediately if child exhibits these signs Tests are available for determining CYP2D6 genotype Consider prescribing alternative analgesics for children

**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. CONFIDENTIAL COPYRIGHT PGXL LABORATORIES 2012

Pharmacokinetic Gene Metabolism Pharmacodynamic Gene Clinical Effect

OPRM1: Mu Opioid Receptor Analgesia Sedation Euphoria Respiratory depression Itching Morphine Mu opioid receptor

OPRM1 118A>G Genotypes AGAAGG Mean effective analgesic concentration = Therapeutic target range

OPRM1: Mu Opioid Receptor Opioid binds OPRM1 to elicit pain relief 118A>G variant decreases receptor availability and may increase dose requirements Morphine mg/24hr Reynolds 2008; Reyes-Gibby 2007; Klepstad 2004

OPRM1 helps predict dose of active opioids Morphine Hydromorphone Oxymorphone

GenericBrandMetabolic RouteReceptor/Dose AlfentanilAlfentaCYP3A4/CYP3A5 Carisoprodol**SomaCYP2C19 CelecoxibCelebrexCYP2C9 Codeine**Various brandsCYP2D6 CyclobenzaprineFlexaril CYP1A2, CYP3A4/CYP3A5 FentanylActiq, DuragesicCYP3A4/CYP3A5 Hydrocodone**Various brandsCYP2D6 HydromorphoneDilaudidUGT2B7 + OPRM1 IbuprofenAdvil, MotrinCYP2C9 LidocaineVarious brandsCYP1A2 MethadoneVarious brandsCYP2C19, CYP2B6 + MorphineVarious brandsUGT2B7 + OPRM1 NaproxenAleveCYP2C9 Oxycodone**Oxycontin, variousCYP2D6, CYP3A4/5 OxymorphoneOpanaUGT2B7 + OPRM1 RopivicaineVarious brandsCYP1A2 TizanidineZanaflexCYP1A2 Tramadol**Ultram, variousCYP2D6 ZolmipitranZomigCYP1A2 **prodrug; + test not yet available

OPRM1 Opioid Interpretations OPRM1 AA OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Normal Opioid Responder Opioid response: Average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. OPRM1 GG OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Poor Opioid Responder Opioid response: Higher then average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. Adjust Dosage Morphine Adjustment Increase up to 80% OPRM1 AG OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Intermediate Opioid Responder Opioid response: Higher then average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. Adjust Dosage Morphine Adjustment Increase 10%

OPRM1 and Naltrexone for Alcohol dependence

OPRM1 and Naltrexone Naltrexone is a competitive mu opioid receptor antagonist – Decreases alcohol cravings – Inhibits endorphin “reward” effects in EtOH/opioid abuse – Decreases relapse risk EtOH

OPRM1 and risk of alcohol relapse 40% of patients treated with naltrexone will relapse 80% of those who relapse have AA genotype Chamorro et al. Addiction Biology 2012;17:

OPRM1 AA carriers treated with naltrexone have highest risk of relapse Chamorro et al. Addiction Biology 2012;17: AA genotype pts are 2x more likely to relapse that G carriers

OPRM1 Combined Interpretations OPRM1 AA OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Normal Opioid Responder / Impaired Naltrexone Responder Opioid response: Average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. Naltrexone response: With respect to naltrexone treatment for alcohol dependence, 80% of treated patients who relapse have the OPRM1 AA genotype. Relapse rate among AA genotype patients is 5% higher than the typical on-treatment relapse rate, and is 2-fold greater than for patients with the AG or GG genotypes.

OPRM1 Combined Interpretations OPRM1 GG OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Poor Opioid Responder / Normal Naltrexone Responder Opioid response: Higher then average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. Naltrexone response: In patients treated with naltrexone for alcohol dependence, those with the GG genotype have a 15% lower average relapse rate compared to the typical on-treatment relapse rate. Overall, relapse rate among G allele carriers is 25% compared to 54% in patients with AA genotype. Adjust Dosage Morphine Adjustment Increase up to 80%

OPRM1 Combined Interpretations OPRM1 GG OPRM1 PhenotypeTherapeutic Implications (adapted from published resources) Poor Opioid Responder / Normal Naltrexone Responder Opioid response: Higher then average doses of morphine typically required (may also apply to other active opioids, eg, hydromorphone, oxymorphone). Note: Formation of active opioid metabolites (e.g., morphine) from prodrugs (eg, codeine) is dependent on CYP2D6 activity. Naltrexone response: In patients treated with naltrexone for alcohol dependence, those with the GG genotype have a 15% lower average relapse rate compared to the typical on-treatment relapse rate. Overall, relapse rate among G allele carriers is 25% compared to 54% in patients with AA genotype. Adjust Dosage Morphine Adjustment Increase up to 80%

NSAIDs

Non-steroidal anti-inflammatory drugs Ibuprofen, naproxen, celecoxib, diclofenac, etc Individual or combination preparations Celebrex (celecoxib) Vicoprofen (hydrocodone + ibuprofen)

NSAID Adverse Events Severe ADRs Ulcer GI bleed Kidney failure MI Stroke Metabolized by CYP2C9

CYP2C9 variants increase risk of NSAID-induced bleeding CYP2C9 GenotypeRisk of GI bleed taking NSAID *1/*11 *1/*23.8 *1/*37.3 Case control study: 26 patients taking NSAID <1 month with confirmed GI bleed vs 52 NSAID users without GI bleeds CYP2C9 genotyping performed Pilotto et al Gastroenterology 2007;133(2):

CYP2C9 and NSAID use CYP2C9 genotyping may identify patient subgroups at increased risk of NSAID-related GI bleeding Use with caution based on other clinical factors

Summary Pearls Opioid prodrug efficacy/ADR: 2D6 Active opioid dose: OPRM1 Naltrexone efficacy: OPRM1 NSAID ADR: 2C9 Other opioids and muscle relaxers: 3A4/5, 2C19, 1A2