How To Prescribe Pain Medications Without Killing People Catherine Casey MD
How To Prescribe Pain Medications Without
Killing People
Catherine Casey MD
Case #1
A 28yo F with MSK pain s/p MVA one week ago is taking ibuprofen 800mg QID and 4-6 oxycodone per day. She does not feel tired, constipated, confused or depressed on this regimen. She does find that the medicine helps improve her function, but that it wears off after 3 hours.
Convert her to OxyContin.
Case #2
A 45 yo M with chronic LBP with sciatica has been taking 2 Vicodin QID for the last eight months. They help his back pain, but the sciatica is still impeding his function.
Suggest a methadone regimen for him.
Case #3
A 54 yo physician on Zanaflex has a UTI. What are you going to prescribe her?
Case #4
A 23 yo F on the inpatient service is on a fentanyl drip at 100mcg/h. You want to convert her to a patch. How do you propose doing this?
Case #5
A 57yo F with NASH cirrhosis sustains a compression fracture. What can you give her, and what should you avoid?
Pain Management Principles
By the mouth
By the clock
By the ladder
By the ladder…
Pain Management Principles
Add non-drug therapies
Differentiate nociceptive from neuropathic pain
Strive for complimentarity
Opiate Principles
Titrate by percents rather than milligrams
Convert short-acting to long-acting
Use equianalgesic doses, but anticipate incomplete cross-tolerance
If you remember nothing else…
SEDATION PRECEDES RESPIRATORY DEPRESSION
Start low and go slow in elderly, liver, and kidney patients. Dose-adjust and use longer intervals.
Reassess frequently
Don’t forget the bowel regimen
ACETAMINOPHEN – nociceptive pain
The “starter drug” of choice, even in folks with kidney or liver disease
Limit to 2g/d in liver disease, 4g/d in healthy folks
Highest risk for hepatotoxicity – alcoholics
NSAIDS – nociceptive pain (but not neuropathic)
Ibuprofen has a NNT=2
Monitor kidney function. If Cr bumps, check for AIN.
Use carefully or not at all in kidney or liver disease.
NSAIDS – nociceptive pain (but not neuropathic)
Use big, scheduled doses for a limited amount of time
Consider adding a PPI or misoprostol, esp in elderly – & NO indomethacin.
No aspirin in kids, teenagers, pregnant or breastfeeding moms
TRAMADOL – nociceptive or neuropathic pain, fibromyalgia
SEROTONIN SYNDROME HAPPENS
Start 50mg Q6h
Can be addictive!
Avoid in liver disease, seizure hx
Max 50mg BID in kidney disease due to prolonged elimination
OPIATES – nociceptive > neuropathic pain
Codeine, Demerol, and Darvocet suck
Kidney pts: No Demerol or Darvocet. Consult before using morphine.
Liver pts: No oxycodone, tramadol, codeine. Fentanyl OK.
Fentanyl patches contraindicated in pts < 110 lbs.
METHADONE – nociceptive & neuropathic pain
Consult a specialist when converting btw methadone & fentanyl.
Starting methadone in an opiate-tolerant pt: 5 mg BID x 7 d, then 5 mg TID. Opiate-naïve or elderly patient: 2.5mg QHS, then 2.5 mg BID after 7 d.
Titrate weekly. NOT A PRN MED!
MUSCLE RELAXANTS – muscle spasm
CIPRO + TIZANIDINE = POTENTIALLY FATAL DRUG INTERACTIONBaclofen – good for lancinating, paroxysmal neuropathic pain.
Tizanidine (Zanaflex) - neuropathic pain & fibromyalgia.
Avoid carisoprodol (Soma). Metabolizes to a sedative. Very addictive.
BENZODIAZEPINES – muscle spasm
BENZOS + OPIATES = INCREASED RISK OF RESPIRATORY DEPRESSION.
Avoid in liver disease. If you must, use Ativan.
Taper slowly.
TRICYCLICS – neuropathic pain
Trazodone 10-25mg is great for sleep in the elderly. Avoid amitriptyline in old folks.
Check EKGs when titrating up either tricyclics or methadone in someone on both, attn: QT interval.
May take a few weeks to fully kick in.
ANTIEPILEPTICS – neuropathic pain, postherpetic neuralgia
Sudden d/c of gabapentin (Neurontin) can cause seizures.
Check electrolytes on topiramate (Topamax).
No carbemazepine (Tegretol) in liver disease.
TOPICALS – muscular or neuropathic pain
Lidoderm patch or capsaicin for periphereal neuropathic pain, menthol-containing ointments for MSK pain, compounded ointments/gels containing NSAIDs, TCAs, and AEDs also available.
ADJUVANTS
steroids, heat/ice, TENS, acupuncture, massage, addressing accompanying depression/anxiety/insomnia
And finally…