Role of Opioid Analgesics

Agent of choice for moderate to severe pain (especially visceral)

Used for limited perioid of time in most patients

Patient Controlled Analgesics

Keeps pain under control

Gets the patient involved

Proper patient selection is critical

Ideal for acute, sharp, post-op pain

Patients activate pump when they feel a little pain

Y-tubing site close to injection site

PCA Potential Errors

(3)

Programming Errors

Pump Failure

PCA by proxy => family member thinking pt is in pain

Patient Controlled Analgesia

Adult Dosing

Intermittent Dose, Lockout Interval, Hour Limit, 4 Hour Limit, Basal Rate

Adult:  25-50 mcg/kg or 2-4 mg morphine

Intermittent Dose:  1 mg

Lockout Interval:  5-10 minutes

Hour Limit:  5 mg

4 Hour Limit:  15-20 mg

Basal Rate:  2 mg/hr

Patient Controlled Analgesia

Potential Benefits of Fentanyl

(2)

Short duration may aid tiration

Less NV, urinary retention, and sedation

Patients who will benefit from basal rate

(4)

Patient who undergo major surgery

Patient who hits limit every hour

Patient with high dosing requirement during first 24-48 hours

Patient who wake up frequently at night with pain

Monitoring Patients PCA

(5)

Every 4 hours until stable

Basal Rate

Number of Attempts

Number of Injections

Ask patient how they feel:  HR, BP, Pain Scale

Adjusting PCA Pumps

(5)

Cut or stop basal rate when patient stops attempts

If patient waits too long between injections, re-bolus

If patient needs more drug:  increase intermittent dose by 50% increasing 1 and 4 hr limit

If this increase dose not work ,increase dose by 50% of the first increase

Always reassess if patient needs to be re-bolused!!!

Epidural/Inthrathecal Analgesia

Usually intentded for short-term use

Useful post-op and some OB patients when epidural catheter is already in place

Useful when pts can NO longer tolerate SE associated with Oral or IV

Useful in terminal patients Not achieving pain relief by conventional means

Used in some pain patients when other treatment proves unsuccessful

Epidural/Intrathecal Analgesia

Monitoring

SEs (2)

Patients must be monitored and stabalized over 48 hour period

Any respiratory depression may be delayed

Itching and Urinary Retention more Common

Risk of infection

Epidural/Intrathecal Analgesia

Dosing is Emperic for (3)

Morphine

Hydromorphone

Fentanyl

USE ONLY PRESERVATIVE FREE PRODUCTS AND DILUENTS

DepoDur

Morphine Extended-Release Liposome Injection

Provides analgesia up to 48 hours

Administered into lumbar spaces prior to surgery

Eliminates need for catheter and pumo

Stored in refrigerator must be used with 4 hours after withdrawing from vial

Clonidine-Duraclon

Ziconotide-Prialt

MOAs

Blocks Alpha-2 Receptor (Best for Neuropathic Pain)

Synthetic peptide from sea snail venom indicated for IT injection to manage severe chronic pain in patients who do NOT respond to other therapies

Managemtn of Chronic Pain

Non-visceral/Non-somatic

Mild to Moderate Pain (4)

Step 1 Options (3)

Arthritis

Neuropathies

Fibromyalgia

Low back pain

APAP

NSAIDs

Tramadol

with Routine Dosing

Management of Chronic Pain

Non-Visceral/Non-Somatic

Step 2 Options (2)

Use SR forms of Step 1 drugs

Long Acting NSAIDs

ER forms of Tramadol

Ultram ER titrate over 5 days

Ryzolt tirate over 5 days

Management of Chronic Pain

Non-Visceral/Non-Somatic

Step 3 Options (3)

Continue Step 1 and 2 drugs

Avoid chronic use of opioids if possible

Conside use of buprenorphine patch

Management of Chronic Pain

Non-Visceral/Non-Somatic

Lower Back Pain

Treatment Guidelines (5)

NSAIDs or APAP

Heat massage, activity, rehabilitation, acupuncture, spinal manipulation

Injectable corticosteroids if there is evidence of inflammation

Muscle Relaxants for acute use only

TCS, gabapentin, topirimate (mixed results)

Opioids should be reserved for pts with severe pain NOT relieved by other agents (less effect with chronic use)

Neuropathic Pain

Often the result of loss of inhibitory activities of the descending pathway on pain transmission

Conditions associated with Neuropathic Pain

(10)

Diabetic Neuropathies

Lower Back Pain

Trigeminal Neuralgia

HIV Sensory Neuropathy

Tumor Infiltration

Post-Herpetic Neuralgia

Cancer Pain

Some Headaches

Spinal Cord Injury

Phantom Limb Pain

Post-Herpetic Neuralgia

Severe Pain

Extremely sensitive to tough or temperature

Feeling of clothing against skin is painful

Condition can last for months

Treatment of Neuropathic Pain

General Principles

(5)

Initiate one drug at a time

Use drugs with the lowest SE profile

Start at low dose, slowly increase dose evaluating benefit vs. SE

for tx failure, try alternative agents within same class

Education:  full benefit may take days to weeks with full pain relief NOT expected

Treatment of Neuropathic Pain

Antidepressants

MOA

Effect

Medications

(4)

Agents with activity against NE and serotonin most effective

Analgesic effect takes at least 1 week

Amitriptyline (Elavil)

Nortriptyline (Pamelor)

Desipramine (Norpramin)

start at 10-25 mg po hs (max 100-150 mg)

Venlafaxine (Effexor XR) 150-225 mg/day

Treatment of Neuropathic Pain

Duloxentine (Cymbalta)

30-60mg/day

Not superior to other antidepressants

Avoid in pts with liver disease

Urinary hesitancy reported

Treatment of Neuropathic Pain

MOA

Medications

(6)

Inhibit glutamate activity

Enhance GABA activity

Carbamazepine

Phenytoin

Gabapentin

Pregabalin

Lamotrigine

Topiramate

Gabapentin

Dosing

Gabapentin Extend-Release (Gralise)

900-1800 mg/day

max:  3600 mg/day

Start at 100 mg TID

Taper when d/c

Marketed for post-herpetic neuralgia

Taken once daily with evening meal

Dose is titrated over 2 weeks to max of 1800 mg

Pregabalin (Lyrica)

Start at 75 mg BID

Titrate to 150 mg BID

No benefit at doses > 300 mg/day

SE dose related

d/c gradually to avoid withdrawl symptoms

Capsaicin Topical Cream

Depletes stores of Substance P which inhibits pain transmission and inflammation

For pain from arthritis and neuropathies

Apply 3-4 times daily

A burning sensation may occur

Wash hands thoroughly with soap and water

Inital relief is usually noted within 1-2 weeks

Daily application is necessary to sustain pain relief

Capasaicin 8% Patch (Qutenza)

Only indicated for PHN

Apply for 1 hours q 3 months

Design for application by HCP

Use only NITRILE GLOVES

Causes slight elevation in BP

Lidocaine Patches 5% (Lidoderm)

Local Anesthetic

No more than 3 (4) patches at a time

Patches can be cut to fit affected area

on for 12 hours, then off for 12 hours

Apply on intact skin

Treatment of Neuropathic Pain

Other Therapies

(6)

Muscle relaxants/Antispasmotic => Tizandiine, Baclofen

Lidocaine injections/Alcohol injections

Clonidine (topical patches)

Ketamine Injection or 5% gel (NMDA receptor antagonist)

Botox injections (paralyzes nerves and muscles)

Fibromyalgia

Characterized by (2)

Statistics

Causes

Sx (4)

Generalized muscle pain, fatigue

Imbalance of serotonin and NE are thought to be involved

Achiness ALL over

Inability to sleep

Stiffiness on wakening

Tiredness during the day

Fibromyalgia

Criteria Classification

(4)

Pain left/right sdie

Pain above/below waist

Pain for > 3 months

Palpable pain at 11 of 18 indentified tender point sites

Fibromyalgia

Therapies with supporting evidence for use

(6)

Amitriptyline

Cyclobenzaprine

Duloxetine

Venlafaxine

Tramadol

Pregabalin

Treatment of Fibromyalgia

Milnacipran (Savella)

SNRI

Only indicated for fibromyalgia

50-100 mg BID

Nausea is common

Monitor BP and HR

Fibromyalgia

Non-pharmacological Treatment Options

(3)

Exercise and muscle strengthening

Cognitive behavioral therapy

Patient education