Lecture 76 - Non-Malignant Pain Part 2 Flashcards
Gabapentinoids: Gabapentin (Neurontin) and Pregabalin
Uses: Fibromyalgia; Neuropathies; Post-operative pain
Available formulations: Tablets/capsule; ER tablet; Liquid solution
Recommended dosing: Gabapentin (Neurontin): 100-300mg PO TID (max 3600mg/day); Pregabalin (Lyrica): 75mg PO BID (max 600mg/day)
Side effects: Sedation, dizziness, peripheral edema
Clinical pearls: Renally dose adjusted; Titrate up dose to limit sedation; Use in combination to ̄ requirements of other analgesics; Pregabalin is a schedule V controlled substance, gabapentin is unscheduled
SNRI’s: Venlafaxine (Effexor) Duloxetine (Cymbalta)
Uses: Fibromyalgia; Neuropathy
Available formulations: Capsule/tablet; ER capsule/ER tablet
Recommended dosing: Venlafaxine: 37.5 – 75mg PO daily (max 225mg/day); Duloxetine: 30mg PO daily x 1 week, then increase to 60mg PO daily (max 60mg/day)
Side effects: Nausea, headache, hypertension, sedation, weakness
Clinical pearls: Start low dose and titrate up to minimize side effects; Renally dose adjust venlafaxine and avoid duloxetine for CrCl < 30 mL/min
TCA’s: Amitriptyline (Elavil)* Nortriptyline (Pamelor)
Uses (all off label): Fibromyalgia; Neuropathy; Migraine prophylaxis
Available formulations: Tablet (amitriptyline); Capsule (nortriptyline); Oral solution (nortriptyline)
Recommended dosing: Amitriptyline or nortriptyline: 10mg PO QHS (max
150mg/day)
Side effects: Anti-cholinergic side effects, sedation
Clinical pearls: Last line option for neuropathy and fibromyalgia due to side effects
Muscle Relaxants: Cyclobenzaprine (Amrix, Fexmid) Baclofen (Lioresal) Methocarbamol (Robaxin) Carisoprodol (Soma) Tizanidine (Zanaflex)
Uses: Musculo-skeletal pain/spasms
Available formulations: Tablet/capsule (IR/XR); Oral suspension (baclofen); Parenteral solution (methocarbamol, baclofen)
Recommended dosing: Cyclobenzaprine 5 mg PO TID (max 30mg/day); Baclofen 5mg PO TID (max 80mg/day); Carisoprodol 250-350 mg PO TID (max 1050mg/day); Methocarbamol 1.5 g PO 3-4x/day (max 8g/day); Tizanidine 2-4 mg PO q8-12h (max 24mg/day)
Side effects: Sedation/ drowsiness, dizziness, dry mouth, vision changes
Clinical pearls: Short term use (<3 weeks); Carisoprodol is schedule IV due to abuse potential
Antiepileptics: Carbamazepine (Tegretol)
Uses: Neuropathic pain
Available formulations: Tablet; ER capsule/tablet; Chewable tablet; Suspension
Recommended dosing: 200mg-400mg PO daily in 2-4 divided doses (max
1200mg/day)
Clinical pearls: Increased risk of hypersensitivity reaction in patient with HLA-B*1502 allele; Autoinduction of hepatic enzymes (levels will fall over first few weeks of use)
Topical Agents: Lidocaine
Available formulations: Patch (4% OTC, 5%); Injection; Topical (cream, gel, ointment, lotion, spray, liquid)
Recommended dosing: Apply 1 patch to affected area daily and remove 12 hours later (can vary by manufacturer)
Side effects: Hypotension, arrythmia (minimal risk with patch)
Clinical pearls: Tachyphylaxis with continuous use; 12 hour break between patches; Local effect- apply to site of pain
Topical Agents: Capsacian
Uses: Muscle/joint pain; Neuropathic pain
Available formulations: Cream, gel, liquid, lotion: Apply 3-4 times per day; Patch: Apply 1 patch to affected area daily and remove 8 hour later u Side effects: Skin irritation and pain
Clinical pearls: Do not get medicine into eyes (burning); Wash hands after applying; Some formulations available OTC
Non-COX-2-selective NSAIDs, oral *includes aspirin >325mg/day in older adutls
Increased risk of GI bleeding or peptic ulcer disease in high-risk groups
Avoid chronic use unless other alternatives are not effective and the patient can take a gastroprotective agent (proton- pump inhibitor or misoprostol
Indomethacin, Ketorolac (oral and parenteral) in older adults
Increased risk of GI bleeding/peptic ulcer disease and acute kidney injury in older adults
Of all the NSAIDS, indomethacin has the most adverse effects, including a higher risk of CNS effects
Avoid
Skeletal muscle relaxants: Carisoprodol, Cyclobenzaprine, Methocarbamol in older adults
Poorly tolerated by older adults because some have anticholinergic adverse effects, sedation, and increased risk of fractures
Avoid
SNRIs, TCAs, Carbamazepine in older adults
May exacerbate or cause SIADH or hyponatremia; monitor Na levels
use with caution
Opioids and benzodiazepines in older adults
Increased risk of overdose and adverse events
Avoid
Opioids and gabapentin/pregabalin in older adults
Increased risk of severe sedation- related adverse events in older adults including respiratory depression and death
Avoid
Exceptions
* Transitioning from opioid to
gabapentinoid
* Using gabapentinoid to reduce
opioid dose
Anticholinergic in older adults
Increased risk of cognitive decline, delirium, and falls or fractures.
Avoid
Antiepileptics (including gabapentinoids)
Antidepressants (TCAs, SSRIs, and SNRIs)
Antipsychotics Benzodiazepines
Z drugs
Opioids
Skeletal Muscle Relaxants
in order adults
Increased risk of falls and fracture with concurrent use of three or more CNS-active agents
Avoid concurrent use of three or more CNS-active drugs
Opioid Antagonist
naloxone
Opioid weak agonist
codeine
tramadol
Opioid full agonist
- Morphine
- Hydrocodone
- Hydromorphone
- Oxycodone
- Meperidine
- Fentanyl
- Methadone
Tolerance
Medication becomes less effective over time and it takes a higher dose of the drug to achieve the same effect
Dependence
When a patient stops using a drug, their body goes through withdrawal
Addiction
Continued use of a drug despite negative consequences
Signs and Symptoms of Opioid Overdose
- Sedation/decreased level of consciousness (LOC)
- Pinpoint pupils
- Decreased respiratory rate
- Bradycardia
- Hypotension
- Pale, clammy skin
Signs and Symptoms of Opioid Withdrawal
- Insomnia/Agitation
- Dilated pupils
- Increased respiratory rate
- Tachycardia
- Hypertension
- Sweating
Treatment of opioid overdose
Naloxone (Narcan): Opioid Antagonist
Available in different formulations: Intravenous (hospital) u 0.4-2mg IV q2-3min; Nasal spray (community); 4mg intranasal spray q2-3min (alternate nostrils)
Can precipitate opioid withdrawal
Prescribe together with opioids in patients at risk for overdose
Naloxone (Narcan)
Who should receive co-prescription of naloxone?
Considering prescribing naloxone for patients at risk of overdose, such as ANY of the following: History of overdose; History of substance use disorder; Higher opioid dosages (≥50 morphine milligram equivalents (MME)/day); Concurrent benzodiazepine use
Opioid Withdrawal
Onset: Short-acting opioids (e.g. heroin): 8-24
hours after last use; duration 4-10 days; Long-acting opioids (e.g. methadone): 12-48 hours after last use; duration 10- 20 days
Treatment: Clonidine - Helps with symptoms of withdrawal such as HTN, sweating, vomiting and anxiety; Buprenorphine; Methadone
