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…