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PTP 546Module 14 & 15

Pharmacology of Pain Management:Acute and Chronic

Jayne Hansche Lobert, MS, RN, ACNS-BC, NP

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Pharmacology of Pain ManagementOpioid Analgesia

• Opioid Agonists: Treatment of Severe to Moderate Pain– Ex: Morphine (Astromorph, Duramorph)– Ex: Fentanyl (Sublimaze; Duragesic )– Ex: Hydromorphone (Dilaudid)– Ex: Methadone (Dolophine)

• Opioid Agonists: Treatment of Moderate to Mild Pain– Ex: Codeine; Codeine/Tylenol (T#3, T#4)– Ex: Hydrocodone (Hycodan); Hydrocodone/Acetaminophen

( Vicodin)– Ex: Oxycodone (Oxycontin); Oxycodone/Acetaminophen

(Percocet)

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Pharmacology of Pain ManagementOpioid Analgesia

• Prototype Opioid Agonist: Morphine• Gold-standard: 30mL is used to evaluate all other pain meds.

– Action: binds with both mu & kappa receptor sites– Therapeutic Effect: treatment of severe pain provides analgesia and

euphoria– Side Effects: sedation, dizziness, hypotension, itching (switch to

different), nausea, constipation (if long term, will always decrease GI mobility), respiratory depression (doctors worry, but really need to look out for sedation as always 1st) , constriction of pupils

– Note: multiple routes multiple half lives to consider; addictive potential physical & psychological dependence

– Note: opioid antagonist is Naloxone (Narcan)=used to STOP, to reverse drug overdose.

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Pharmacology of Pain ManagementOpioid Analgesia

• Treatment Considerations– Route

• Oral; Transmucosal-Lollipop (used for children-expensive)• Intravenous: Patient Controlled Analgesia Pumps, Continuous IV, Bolus IV• Epidural: Epidural Pumps- usually at home; Intrathecal (into brian) - Subcutaneous, Transdermal • Rectal or suppository

– Half Life• Impacted by route of administration• Impacted by formulation: ex: sustained release

– High Alert Medications • Controlled substances• Require special precautions• Addictive potential

– Equianalgesia• All pain meds judged in relation to morphine• Charts are available

– Adjunctive Meds and Treatments

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Pharmacology of Pain Management

• Prototype Opioid Antagonist: Nalaxone (Narcan)– Action: blocks both mu and kappa receptors– Therapeutic Effect: complete or partial reversal of

opioid effects– Side Effects: rapid loss of analgesia hypertension,

hyperventilation, pain – Note: administered when opioid overdose is

suspected; IV administration reversal in minutes

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Pharmacology of Pain Management

• Other Pain Management Medications– NSAIDS

• Inflammation is what causes the pain so NSAID (anti-inflamatory) used to decrease pain.

• ASA, Motrin, Toradol, etc.

– Centrally Acting Drugs• Tramadol (Ultram)

– Miscellaneous Agents/Classes• Acetaminophen (Tylenol)• Antidepressants

– Elavil

• Anticonvulsants – Neurotin, Dilantin

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Pharmacology of Pain Management

• Other Pain Management Medications• NSAID’s– Ex: Acetylsalicylic Acid(Aspirin/ASA) – Ex: Ibuprofen(Motrin)– Ex: Ketorolac (Toradol)

– Treatment Issues & Considerations• Used for anti-inflamatory effect that will decrease pain.

– Side Effects: Gi bleeding, peptic ulcer, dyspepsia, Kidney dysfunction. • No Aspirin/Motrin if h(x) of GI bleeds from NSAID’s

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Pharmacology of Pain Management

• Other Pain Management Medications– Centrally Acting Drugs: Tramadol (Ultram)• Action: weak binding of mu receptors but also relieves

pain by inhibition of norepinephrine and serotonin reuptake• Therapeutic Effect: treatment of moderate pain,

chronic pain. • Side Effects: vertigo, dizziness, headache, lethargy,

nausea and vomiting

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Pharmacology of Pain Management

• Other Pain Management Medication– Ex: Acetaminophen (Tylenol)• Action: inhibits synthesis of prostaglandins which

mediate pain and fever• Therapeutic Effect: analgesia; antipyresis• Note: No anti-inflammatory properties• Side Effects: liver failure; hepatoxicity with excessive

intake• Note: Adult daily max= 3- 4 grams/day; note OTC and

prescribed combination meds with acetaminophen; dose reduction with alcoholism

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Pharmacology of Pain Management

• Other Pain Management Medications– Ex: Anticonvulsants• Gabapentin (Neurotin)• Topiramate (Topamax)

– SE: fatigue, drowiness

– Ex: Antidepressants• Amitriptyline Hydrochloride (Elavil)

• Treatment Issues and Considerations?• Side Effects?

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Pharmacology of Pain Management

• Opioids: Treatment Issues– Physical & Psychological Dependence

• Incidence: more over-dose on opioids then heroine and cocaine. • Treatment

– Pharmacological: suppression withdrawal symptoms associated with detoxification

– Withdrawal Sx: restlessness, anxiety, insomnia, chilled, tremors, and a high death rate if untreated. » Methadone: liquid» Buprenorphine hydrochloride (Bupernex): sublingual

• Maintains drug: lower analgesic potential» Suboxone: naloxone & buprenorphine (newest)

• Non-Pharmacological: individual and group therapy, use (methadone) to decrease dependence.

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Pharmacology of Pain Management

• Patient Controlled Analgesia (PCA)– Self administration of opioids (typically IV) in small

frequent doses using a special pain pump– Clinical Use: post operative acute pain and chronic

pain management– Advantages:• Immediate administration of medications• Equal or superior analgesia• Less opioids used therefore less side effect potential

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Pharmacology of Pain Management

• PC A Dosing Strategies– Loading Dose

• One time initial dose-wake up call in the morning

– Basal Dose/Background Dose• Hourly continuous dose: 7am to 7pm

– Demand Dose• Patient administered dose

– Lockout Intervals• Allowed frequency of demand dose; ex: every 10 minutes, always have

another HCW validate.

– One Hour and Four Hour Max Limit• Equals basal dose and max demand dose

– Total demand dose attempted versus Total demand dose successfully delivered

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Pharmacology of Pain Management

• Administration Routes for PCA– Intravenous

• Short term: peripheral IV access • Long term: long term venous access

– Epidural• Short term: external catheter placed in subarachnoid space• Long term: tunneled subarachnoid catheter is connected to an internal

access port or drug reservoir

– Transdermal• Long term: external patch with button

– Regional: typically local anesthesia similar to one time blocks• Short term: catheter placed in joint or wound near peripheral nerves• Advantages/Complications: local effect, less side effects?

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Pharmacology of Pain Management

• Medications used for PCA– Opioid

• Morphine• Hydromorphone (Dilaudid)• Meperidine (Demerol)-rarely used.

– Side Effects: sedation, hypotension, itching, nausea, vomiting, respiratory depression

– NonOpioid• Bupivacaine (Marcaine)-Epidural sometime bad SE.• Ropivacaine (Naropin)

– Side Effects: sedation, hypotension, itching, nausea, vomiting, respiratory depression, numbness, tingling, motor impairments, urinary retention

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Pain Management

• Principles– Always ask about the presence of pain– Perform a comprehensive pain assessment– Avoid IM injections– Treat persistent pain with scheduled meds– Use shorting acting strong opiates to treat moderate to server pain

• Morphine, hydromorphone, oxycodone

– Use long acting strong opiates once pain is controlled and can detect the cycle, so not always “chasing” the pain. • Ms contin, fentanyl patch, oxycontin

– Mange opioid SE aggressively. • Ex: constipation will negatively effect adherence.

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Pain Management

• Acute Pain: – Pharmacological: • Opioids• Non-opioids (NASIDS- gi bleeding and Tylenol=liver

damage)• Antidrepssents, anticonvulsants, local anesthetics.

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Pain Management

• Chronic Pain: > then 3 months– Chronic Pain: rate pain lower, as they learn to tolerate the pain.

• How is it affecting your life?

– Pharmacological• Opioids• Non-Opioids: NSAIDS and Tylenol• Adjuvants: anti-depressents, anticonvulsants, local anesthetics.

• Other: PT, heat, cold, E-stem, message, acupuncture, distraction, imagery, support, other CAM, ablative technique, botulism toxin, epidural steroids.