final 07-2019 noma 2019 4pm pain medicine...
TRANSCRIPT
PAIN MEDICINE PHARMACOLOGICAL
REVIEW
John M. DiMuro, DO, MBAAnesthesiology & Pain MedicineDiMuro Pain Management
Reno & Las Vegas
NOMA 2019 Las Vegas
PAIN MEDICINE PHARMACOLOGICAL
REVIEW
AGENDA
▪Most common classes of pain medications
▪What each class is best treating▪Common side effects
▪Relevant details▪On the horizon…
PAIN MEDICINE PHARMACOLOGICAL REVIEW
CLASSES OF PAIN MEDICATIONS
1) NSAIDs
Best to treat for: Acute painMost notable side effects: Vascular complications, GI distress, bleeding
PAIN MEDICINE PHARMACOLOGICAL
REVIEW
CLASSES OF PAIN MEDICATIONS
1) NSAIDsAspirin, Celebrex, Diclofenac, Ibuprofen
• Prostaglandins promote inflammation that isnecessary for healing, but also results in painand fever. Prostaglandins are produced withinthe body's cells by the enzyme cyclooxygenase(COX). There are two COX enzymes, COX-1and COX-2. However, only COX-1 producesprostaglandins that support platelets andprotect the stomach.
• Nonsteroidal anti-inflammatory drugs block theCOX enzymes and reduce prostaglandinsthroughout the body. As a consequence,ongoing inflammation, pain, and fever arereduced. Since the prostaglandins that protectthe stomach and support platelets and bloodclotting also are reduced, NSAIDs can causeulcers in the stomach and promote bleeding.
PAIN MEDICINE PHARMACOLOGICAL REVIEW
CLASSES OF PAIN MEDICATIONS 1) NSAIDs
Can be used for both acute and chronic pain BUTIncreased risk for long-term administration and
especially in the perioperative period.
NSAIDsCOX selectivity
ANALGESIC MEDICATIONS
NSAIDsNonsteroidal anti-inflammatory drugs block the COX enzymes and reduce the release of prostaglandins throughout the body. As a consequence, ongoing inflammation, pain, and fever are reduced.
1SAIDsActually interfere with the synthesis of COX as they suppress the immune system.Best treatment for: Chronic diseaseCommon side effects: ….
2
STEROIDSAre not benign!
STEROIDS
Bone loss
Reduces sex hormone levels
Hypercalciuria
Myopathy
Avascular necrosis
Increase serum lipids
Hyperglycemia
HTN
Psychiatric effects
Gastritis
ANALGESIC MEDICATIONS
Muscle Relaxants
Best for: Myalgias, insomniaSide effects: Somnolence
NSAIDs
SAIDs
MUSCLE RELAXANTS▪Flexeril: CNS at brain stem
▪Baclofen: Stimulation of Gabaβ
▪Zanaflex: α-2 agonistSkelaxin: ?
ANALGESIC MEDICATIONS
NSAIDS SAIDS MUSCLE RELAXANTS
ANTI-NEUROPATHIC AGENTS
Gabapentin: ?Lyrica: ? α-2 delta subunitTopamax: ? But thought to be blockage of Na channels, augment GABA, block AMPA, inhibit carbonic anhydrase
Best: Peripheral neuropathySide Effects: Somnolence, weight gain (not Topamax)
ANALGESIC MEDICATIONS
NSAIDs SAIDs Muscle relaxants
Anti-neuropathic
agents
ANTI-DEPRESSANTS
TCAs•Amitriptyline: ? but
inhibits NE and S•Nortriptyline: ? but
inhibits H, S, Ach
•Best for: Peripheral and spinal neuritis
•Side effects: Somnolence, weight gain
ANALGESIC MEDICATIONS• NSAIDs
• SAIDs
• Muscle relaxants• Anti-neuropathic agents
• Anti-depressants
MY FAVORITES:
• 6) Alpha agonistsClonidine: reduced CNS outflowTizanidine: increases inhibition of pre-synaptic
motor neurons
ANALGESIC MEDICATIONS
MY FAVORITES:
• 6) Alpha agonistsClonidine: reduced CNS outflowTizanidine: increases inhibition of pre-synaptic
motor neurons
Best for: Hypersensitivity, diffuse painSide effects: CV, somnolence
MY FAVORITES
6) Alpha agonists 7) NMDA blockersKetamineMethadoneNamendaMagnesiumDextromethorphan
Best for: Severe and refractory pain, nociceptive & neuropathic pain
Side effects: Sedation
Routes of Administration
Sublingual
Implanted
Mucosal
Inhalation
TOPICAL
PR
IM
IV
PO
Intraspinal
ANALGESIC MEDICATIONS
BENZODIAZEPINES
• Best used for: Muscle relaxation, insomnia,
anxiety
• Side effects: Sedation, addiction
ANALGESIC MEDICATIONS
NSAIDs
SAIDs
Muscle relaxantsAnti-
Neuropathic agents
Anti-depressants
Alpha agonists NMDA blockers
Benzodiazepines
TRAMADOL
What is TRAMADOL?
• Synthetic OPIOID analgesic (direct from package insert)
• Indicated for moderate to moderate severe pain
• Binds mu receptor• Weak inhibitor of NE and S reuptake
• Partially antagonized by naloxone• Peak plasma in 2-3 hours
• 30% excreted unchanged in urine
• 60% excreted as metabolites
TRAMADOL
CONCERNS• Increased risk of seizures with concomitant use of multiple drugs including anti-depressants
• SEROTONIN SYNDROME
SEROTONIN SYNDROMEFig. 1: Mechanisms of serotonin syndrome. (1) Increased doses of L-tryptophan will proportionally increase 5-hydroxytryptamine (5-HT or serotonin) formation. (2) Amphetamines and other drugs increase the release of stored serotonin. (3) Inhibition of serotonin metabolism by monoamine oxidase (MAO) inhibitors will increase presynaptic 5-HT concentration. (4) Impairment of 5-HT transport into the presynaptic neuron by uptake blockers (e.g., selective serotonin reuptake inhibitors, tricyclic antidepressants) increases synaptic 5-HT concentration. (5) Direct serotonin agonists can stimulate postsynaptic 5-HT receptors. (6) Lithium increases postsynaptic receptor responses. From Elsevier Science (Critical Care Clinics 1997;13[4]:763-83). Photo: Chesley Sheppard
SEROTONIN SYNDROME
• Common presentation: The most common presenting symptoms and signs are confusion, agitation, diaphoresis, tachycardia, myoclonus, and hyperreflexia.
OPIOIDSWhat to do about opioid prescribing?
OPIOIDSOpioid drugs bind to opioid receptors centrally and peripherally
• GOOD• Provide excellent analgesia
• Can obtain better analgesia with higher doses
• CV stable
HELP!• BAD• Provides such great analgesia they
can be addicting
• Dose-dependent effects can lead to overdose and death
• Decrease respiratory rate
MOST COMMONLY PRESCRIBED OPIOIDS
• Short-acting• Hydrocodone• Oxycodone• Morphine• Tramadol• Hydromorphone• Oxymorphone
• Long-acting• Zohydro, Hysingla• Oxycontin, Xtampza• MS Contin, Arymo• Methadone• Exalgo, Palladone• Opana ER
OPIOIDS
• Best for acute pain
• Well-tolerated with chronic pain but patient needs to have routine follow-up
• Tool in the toolbox• Don’t be scared!
• Use the PDMP• Follow the opioid law –
AB474
On the horizon ….
• NKTR – 181 (Loxicodegol)• Selective mu opioid
agonist• Less euphoria• Reduction in CNS side
effects• Reduced rate of entry
into the brain
On the horizon …
• TANEZUMAB• Monoclonal antibody
against nerve growth factor
Take Home Points
▪There are multiple medical classes to choose from when treating pain▪There are multiple routes of administration for analgesics▪Be careful with polypharmacy regiments
▪Make sure you have an evidence-based diagnosis▪Use the PDMP▪Understand Nevada AB474-Opioid Law▪Understand how these drugs work▪Don’t be afraid to refer out to a specialist early in the case▪Don’t be afraid to ask for help!▪Like everything else, moderation is the key
