How To Prescribe Pain Medications Without Killing People

How To Prescribe Pain Medications Without Killing People Catherine Casey MD

Case #1 A 28 yo F with MSK pain s/p MVA one week ago is taking ibuprofen 800 mg 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 Oxy. Contin.

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 100 mcg/h. You want to convert her to a patch. How do you propose doing this?

Case #5 A 57 yo 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 2 g/d in liver disease, 4 g/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 50 mg Q 6 h Can be addictive! Avoid in liver disease, seizure hx Max 50 mg 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 opiatetolerant pt: 5 mg BID x 7 d, then 5 mg TID. Opiate-naïve or elderly patient: 2. 5 mg QHS, then 2. 5 mg BID after 7 d. Titrate weekly. NOT A PRN MED!

MUSCLE RELAXANTS – muscle spasm CIPRO + TIZANIDINE = POTENTIALLY FATAL DRUG INTERACTION Baclofen – 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 -25 mg 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

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