Morphine

Cheryl HunterLamar University

November 12, 2015

Morphine

Drugso 212.1 million drugs prescribed in the ED in 2008o Analgesics most prescribed drug class in ED in 2011(Center

for Disease Control and Prevention [CDC], 2011, table 2).• Morphine is the standard (Wenderworth, Kaneda, Amini, Amini, &

Patanwala, 2013). • 8% of patients in the ED receive at least one dose! (Wenderworth

et al., 2013).

http://www.theguardian.com/science/2007/aug/04/sciencenews

The Emergency Department

Paino Accounts for 78% of emergency room visits(Todd et al., 2007). o Complex and difficult to defineo Varied etiology (Belden, DeFriez, & Huether, 2012).

http://www.doctorramey.com/the-pain-that-is-back-pain-part-one/

Morphine Pharmacodynamics

o Pure opioid agonisto Mimics action of opioid peptides to bind with

mu receptors in pain centers of the CNS and spinal cord• Produces analgesic effect (Foy & Peterson, 2013; Lehne, 2013).

o Effective pain reliever• Best for severe, chronic, dull pain• Generally lowers pain 2 points on pain scale (Wenderworth et al.,

2013)• Pain more tolerable and less distressing• Reduces anxiety• Creates sense of well-being (Lehne, 2013)

Morphine Potential Drug Interactionso Alcoholo Antihistamineso Benzodiazepineso Antidepressantso Phenothiazineso Antihypertensiveso Opioid agonistso Agonist-antagonist opioid (Lehne, 2013).

http://www.fierceemr.com/story/analysis-doc-notes-ehrs-can-flag-drug-interactions/2013-04-11

Morphine

Adverse Effectso Urinary Retentiono Constipationo Respiratory distresso Orthostatic

hypotensiono Tolerance &

Dependence

o Nausea & Vomitingo Itchingo Dizzinesso Drowsinesso Dysphoria (Foy & Peterson,

2013; Lehne, 2013; Miller, Schauer, Ganem, & Bebarta, 2015).

Morphine Pharmacokinetics

o Administration routes• PO, Rectal, IV, IM, intrathecal or intraspinal

o Distribution• Throughout the body• Limited lipid solubility

• Small amounts cross blood brain barriero Metabolism

• Almost completely in the liver• Three hour half-life• PO administration subject to first-pass effect

• Requires higher doseso Absorption

• GI tracto Excretion

• Renal (Foy & Peterson, 2013; Lehne, 2013) http://www.thetruthaboutforensicscience.com/pharmacology-part-2-pharmacokinetics/

Morphine Pharmacogenomics

o Variations to the mu opioid receptor gene • Changes in pharmacodynamics and pharmacokinetics

• 118G allele require higher doses than 118A allele• G genotype have decreased analgesic response (Sia et al., 2013)

o Variations to CYP2D6 • Determine rate of metabolism

• Poor metabolizers• Intermediary metabolizers• Extensive metabolizers• Ultra-rapid metabolizers

• (Chummun, 2011; Sia et al., 2013; Wu & Kearney, 2013).

http://www.brunswick.k12.me.us/bhslibrary/genetics-research-ms-kirk/

Morphine Binding Interactions

o Naloxone (Narcan)• Pure opioid antagonist• Structurally comparable to morphine

• Competes or blocks morphine at opioid receptors• Reduces pharmacological effects

• IV,IM or Sub Q• Hepatic metabolism

• Two hour half-life• Rapid first-pass effect makes PO route ineffective (Foy & Peterson,

2013; Lehne, 2013).

Morphine & The Emergency

Department Interprofessional Team Communication and Patient Safety o Morphine Order Sets

• Developed by interprofessional team • Physicians• Nurses• Pharmacists

• Increase safety in ordering and administrationo Incident Reporting

• Adverse drug reactions• Sentinel events• Best practice improvements

http://certification.acsm.org/blog/2013/may/interprofessional-competencies-in-healthcare-four-core-domains

Morphine & The Emergency Department Conclusion

o The benefits of understanding the pharmacodynamics, pharmacokinetics and pharmacogenomics of Morphine. . . • Assessment

• Signs and symptoms • Adverse reactions r/t morphine administration and disease process

• Drug interactions• Efficacy• Drug toxicity

• Genetic Variation• Rate of metabolism

• Practice• Patient Advocate

• effective• Safe, competent care

References Belden, J., DeFriez, C., & Huether, S. E. (2012). Pain, temperature, sleep and sensory function. In S. E. Huether & K. L.

McCance (Eds.), Understanding pathophysiology (5th ed., pp. 324-345). St. Louis, MO: Elsevier. Center for Disease Control and Prevention. (2011). National hospital ambulatory medical care survey: 2011 emergency

department summary tables [Report]. Retrieved from http://www.cdc.gov/nchs/data/ahcd/nhamcs_emergency/2011_ed_web_tables.pdf

Chummun, H. (2011). Understanding pharmacogenomics: Applications in prescribing. Nurse Prescribing, 9(8), 402-407. Retrieved from http://www.nurseprescribing.com/

Forero, R., Mohsin, M., McCarthy, S., Young, L., Leraci, S., Hillman, K., ... Phung, H. (2008). Prevalence of morphine use and time to initial analgesia in an Australian emergency department. Emergency Medicine Australasia, 20, 136-143. http://dx.doi.org/10.1111/j.1742-6723.2008.01068.x

Foy, M., & Peterson, A. M. (2013). Principles of pharmacology in pain management. In V. P. Arcangelo & A. M. Peterson (Eds.), Pharmacotherapeutics for advanced practice (3rd ed., pp. 79-95). Ambler, PA: Lippincott Williams & Wilkins.

Lehne, R. A. (2013). Pharmacology for nursing care (8th ed.). St. Louis, MO: Elsevier. Miller, J. P., Schauer, S. G., Ganem, V. J., & Bebarta, V. S. (2015). Low-dose ketamine vs morphine for acute pain in the ED: A

randomized controlled trial. American Journal of Emergency Medicine, 33, 402-408. http://dx.doi.org/10.1016/j.ajem.2014.12.058

Peterson, A. M. (2013). Pharmacokinetic basis of therapeutics and pharmacodynamic principles. In V. P. Arcangelo & A. M. Peterson (Eds.), Pharmacotherapeutics for advanced practice (3rd ed., pp. 15-29). Ambler, PA: Lippincott Williams & Wilkins.

Sia, A. T., Lim, Y., Lim, E. C., Ocampo, C. E., Lim, W., Cheong, P., & Tan, E. (2013). Influence of mu-opioid receptor variant on morphine use and self-rated pain following abdominal hysterectomy. The Journal of Pain, 14(10), 1045-1052. http://dx.doi.org/10.1016/j.jpain.2013.03.008

Wenderworth, B. R., Kaneda, E. T., Amini, A., Amini, R., & Patanwala, A. E. (2013). Morphine versus Fentanyl for pain due to traumatic injury in the emergency department. Journal of Trauma Nursing, 20(1), 10-15. http://dx.doi.org/10.1097/JTN.Ob013e31828660b5

Wu, A. H., & Kearney, T. (2013). Lack of impairment due to confirmed codeine use prior to a motor vehicle accident: Role of pharmacogenomics. Journal of Forensic and Legal Medicine, 20, 1024-1027. http://dx.doi.org/10.1016/j.jflm.2013.09.019