Formulary Analgesic Medications
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Brian Erickson, MD
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Clinical Assistant Professor,
Psychiatry, UVM
FAHC Center for Pain
Medicine
Psychiatry Consultation
Service
Electroconvulsive Therapy
UVM Program in Integrative
Health
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Acute Pain
Opioids
Codeine morphine
Hydrocodone hydromorphone
Oxycodone oxymorphone
Fentanyl patch
Methadone
Levorphanol
Buprenorphine
Freye, E. (2008). Opioids in Medicine: A comprehensive review on the mode of action
and the use of analgesics in different clinical pain states. New York: Springer
Publishing Co.
Smith, H. (2009). Opioid metabolism. Mayo Clinic Proceedings, 84(7), 613-624
Codeine
“mild opioid” 130 mg = morphine 30 mg
May be combined with Tylenol, Butalbital
Available in 15, 30, 60 mg
Max dose 60 mg q4hr (higher dose not
more analgesia, more side effects
Half-life 2.9 hr
Codeine
Metabolites: codeine-6-glucuronidate
morphine (10%)
Renal excretion
Caution ultra-rapid metabolizers CYP2D6
convert to morphine more rapidly with
increased effects
Caution alcohol, benzodiazepines,
Codeine—Practice Agreement
“Universal Precautions” with opioids
Screen for history of substance abuse
Random drug screens
Lost/stolen scripts not refilled
One pharmacy
Involve family members
Document discussion of risks/benefits
Cautions with Opioids
May cause depression/mania
Constipation, sedation, nausea, myoclonus
Decrease testosterone levels
Methadone – metabolite long half-life; QRS
Opioid-Induced Hyperalgesia
Death – patient, others
Krantz, M., Martin, J., Stimmel, B., Mehta, D. & Haigney, M. (2009). QTc interval screening in
methadone treatment. Annals of Internal Medicine, 150(6), 387-395.
Tenant, F. (2009, Nov/Dec). Testosterone replacement in female chronic pain patients. Practical Pain
Management.
Webster, L. & Dove, B. (2007). Avoiding opioid abuse while managing pain. North Branch, MN:
Sunrise River Press.
Ultram (tramadol)
Non-opioid– affinity for mu-receptor 10x
less than codeine
Metabolite o-desmethyltramadol 200x
greater affinity that tramadol
Inhibits serotonin and norepinephrine reuptake (similar but less than SNRI)
Lower abuse potential than opioids
Tramadol
•Available 50 mg tabs
•Sustained Release 100mg,200mg,300mg
•Dosage: 50 mg q 6hr prn
•May use 50 mg qid
•Max dose 100mg qid
•Studied in osteoarthitis, back pain, others
•Side effects: dizziness, nausea,
constipation
Tramadol--warnings
Seizure risk: reported in recommended
dosage range, increased risk combined
with TCA, SSRI, SNRI, opioids, MAO-I
Serotonin Syndrome: other serotonergic
drugs– triptans, neuromuscular
activity,autonomic activity, altered mental
status
Tramadol—warnings (cont)
Serotonin Syndrome management:
--stop agents, iv hydration, consider
cyproheptadine
Suicide warning—class warning with
antidepressants
Caution with alcohol, CNS depressants
Pregnancy cat C
Neurontin (gabapentin)
Structure similar to GABA, no known direct
activity on GABA receptor
Acts on alpha-2 sub-unit Calcium Channel
receptor in spinal cord
Approved for Partial-Complex
Seizure,Post-Herpetic Neuralgia,
Used for neuropathic pain, migraine,
Fibromyalgia (similar to Lyrica), CRPS
Gabapentin
May help anxiety
Sleep: enhance slow-wave, help Fibro
Not helpful in Bipolar D/O
Half-life 5.9 hours
Renal excretion, caution renal impairment
Side effects: somnolence, peripheral
edema, weight gain, cognitive effects
Gabapentin
•Available 100mg, 300mg,600mg,800mg
•Dosage 100mg hs
• 100mg tid, increase by 100mg tid q 3days
•Max 800mg two qid
• Pregnancy cat C
Flexeril (cyclobenzaprine)
Relieves muscle spasm of local origin
without interfering with muscle function
Not act at neuromuscular junction
Mechanism of action unknown, thought to
act at brainstem rather than spinal level
Similar in structure and effect to tricyclic
anti-depressants
Half-life 3.2 hrs
Cyclobenzaprine
Primarily renal excretion
Some hepatic metabolism –caution p450
metabilism, CYP2D rapid metabolizers
Caution with TCA, MAO-I
Side effects anticholinergic: dry mouth,
constipation, urinary retention, vision,
cognitive, sedation
Caution alcohol, CNS depressants
Cyclobenzaprine
Available 5mg, 10mg
Amrix(cyclobenzaprine extended
release),15mg,30mg
Dosage 5mg tid to 10mg tid
Amrix 15mg to 30mg qd
Soma (carisoprodol)
Muscle spams, low back pain
Mechanism of action unknown
Metabolized to meprobamate (carbamate,
resembles barbituate)
Side effects drowsiness, dizziness,
headache,
Caution porphyria
Caution of CNS agent
Carisoprodol
Available 250mg, 350mg
Dosage 250mg hs
May use 250qid up to 350 qid
Concern for misuse, street value
Compounded Formulations
Topical, sublingual, rectal, nasal delivery
avoid systemic side effects, metabolism
problems
NSAID—ketoprofen
Neuropathic agents—amitriptyline,
gabapentin
Muscle relaxants—MgCl, baclofen
Topical anesthetics—bupivicaine
Compounded formulations (cont)
Intranal Lidocaine—migraines
Rectal baclofen—spasms
Naturopaths can’t use Schedule II presently
Some insurances will pay for compounds
Adjuvants to Opioids
(Nitric Oxide activity)
Oxytocin 10 units q3-6 hr
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Helps mood, anxiety, sexual interest
Side effects – fluid retention, vasopressin
(Kovacs, 1993)
L-Arginine 1000 mg bid
Kovacs (1993). Role of oxytocin in neuroadaptation to drugs of abuse.
Psychoneuroendocrinology, 19(1), 85-117.