Pain Control in Hospice and Palliative Care

Scott Akin MD

Background

• Many patients die in pain– 62-90% of children report pain at end of life– Prevalence of pain 64% in advanced cancer– Pain common in non-cancer (CHF, cirrhosis,

HIV) patients common as well (40% w/in days of death)

Effective pain management

• Three step process(1) Assessment all types of pain (physical,

emotional, spiritual)…if physical, what kind?

(2) Treat each type of pain individually, focusing on specific etiology of each

(3) Continual reassessment of treatment goals (pain levels, goals of function, mood, sleep, social interaction, etc.)

Determining type of Pain

• Nociceptive…tissue damage– Visceral: Difficult to localize (from stretching,

compression, obstruction, infiltration, ischemia)• “Spastic, cramping, gnawing, squeezing, pressure”

– Somatic: Localized• “Aching, stabbing, throbbing, squeezing”

• Neuropathic…nerve damage• “burning, shooting, tingling, stabbing, scalding,

painful numbness”

WHO Analgesia Ladder for cancer pain

• Step 1: Acetaminophen, NSAID, or another adjuvant analgesic. Skip this if in moderate or severe pain!

• Step 2: add lower potency opioid (codeinehydrocodone) or low dose of stronger opioid (morphine). Use ATC dosing along with PRN.

• Step 3: add/start higher potency opioid (morphine, hydromorphone, or fentanyl).

-Don’t need to “climb the ladder.”

-Can use adjuvant meds (antidepressants, anticonvulsants, anticholenergics) at any step.

Adjuvants to opioids

• Acetaminophen (consider scheduled)

• NSAIDS (esp for bone mets, inflammation)

• Bisphosphonates (for bony pain)

• Steroids (for inflammation/edema)

• TCAs/anticonvulsants (tegretol,gabapentin) for neuropathic pain

• Local measures (capsaicin, lidocaine patch)

Drugs to Avoid on Hospice/palliative Care Settings

• Meperidine (demerol): low potency orally, toxic metabolites may precipitate seizures & confusion. Really, only one indication for it: Rigors

• Mixed agonist-antagonists (pentazocine): no more potent than codeine, risk of hallucination & agitation. Inhibits analgesia of morphine

• Propoxyphene (darvocet): no more potent than acetaminophen, toxic metabolites can precipitate seizures, confusion, cardio toxic, resp depression

• Don’t give anything IM!

Treating Nociceptive pain: Opioids

• Opioid myths– “Opioids commonly cause respiratory depression”…

not if administered and titrated carefully. OK, you should worry if RR <6, has ALOC, or is hypoxic. Be careful with narcan…rather than give 0.4mg x 1, much more humane to dilute into 9ml of NS, and give 1-2ml at a time, slowly, until patient responds.

– “Opioids cause addiction”…Physical dependence, yes…but addiction (impaired control over drug use, compulsive use, continued use despite harm)…almost never.

More opioid Myths

• “Opioids hasten death”…maybe the other way around (pain is psychologically and physically destructive, so unrelieved pain may shorten survival time).

• “Oral opioids are ineffective”…not true, but they do take longer to take effect, but oral opioids are preferable because of:– Cost, ease in administration, less risk of infection (no

need to have IV in place), less chance of dosing error, and more predictable pharmacologic steady state.

Even more opioid myths

• “Opioids commonly cause nausea”…false, and if true for specific patient, we have good meds to help (or can switch to another opioid).

• “Opioids commonly cause euphoria”…Not in patients who are in pain. A patient’s mood and sleep is likely to improve with effective relief of pain.

• “Patients rapidly become tolerant to opioids”…not true, but will need higher doses when disease progresses.

Basic opioid principals

• There is significant variation from one individual to another in effective dose.

• Take pt’s age, weight, and prior experience with opioids into account

• Use oral route if able (just as effective)…IV only if unable to take POs, have decreased LOC, or uncontrolled pain

Opioid principals

Know pharmacology:– Short-acting PO meds generally reach their peak after

45-60min, and last 3-5 hours (IV peak is about 5-15min and duration is 1-2 hours).

– Most short-acting PO meds (morphine, oxycodone) can be increased safely q 2 hrs (inc by 25-50% for mild/mod, and 50-100% for mod/severe pain).

– Long acting meds (ms-contin/oxycontin) should be increased every 24 hours, based on PRN use.

– Should not increase methadone more often than q 4-7d.

More opioid basic principals

• At first, use short acting drug, then based on 24 hour need convert to long acting…with PRN for breakthrough (which should be approx 10% of 24 hour dose).

• Example: In “normal” person start q 4 hour– 5mg of short acting morphine or– 1mg hydromorphone (dilaudid)

Then what?

• Add PRN on top of scheduled. The PRN dose should be about 10% of 24 hr dose (in our patient, if morphine, that = 3mg…10% of 30mg=3mg)

• After 24 hours, calculate the total opioid dose needed, and change to long acting preparation

*Per our example, 5mg of short acting morphine q 4 hours = 30mg of morphine daily….let’s say pt

needed 3 PRN doses (3mg x 3 = 9mg, so now your 24 hour need is 39mg (about 40mg).

Then what?

• So, change to long acting morphine (oxycontin or ms contin) 20 mg PO BID, and keep a PRN…but since you want PRN to be 10% of total 24 hour dose, increase PRN to 4mg (10% of 40mg daily need) PO q 3 hours.

What about switching from one opioid to another?

• Must account for “incomplete cross-tolerance”?…the tolerance of a currently administered opiate that does not extend completely to other opioids…which tends lower the dose of the second opioid

• How much do you reduce the second opioid?…25-50%

Example

• Patient on oral morphine 60mg BID, getting very nauseated, vomiting…want to switch to IV hydromorphone (dilaudid).– Total daily dose of morphine= 120mg (60 x 2)

– Conversion of oral morphine to IV dilaudid is 30:1.5 (Google for “opioid equivalent calculator”)

– 120 = 30 x = 6mg IV hydromorphone (per 24 hrs)

X 1.5

Example (cont)

• So, the 24 dose equivalent of the previous oral morphine is 6mg IV hydromorphone

• Divide by 25-50% to account for cross tolerance...we’ll use 50% so, 3mg/ 24 hrs

• To convert to hourly drip, divide 3mg by 24 hours = 0.1mg/hr

Example (cont)

• So, the patient is on 0.1mg an hour…what do you set as the PRN dose?– 10% of 24 hour dose (3mg) would be 0.3mg…

so set that as the patient administered dose on the PCA.

Call from 4B: “Doctor, this patients pain is not controled”

• Just increase the drip right? – NO! Bolus 2-3 times the current basal dose,

THEN increase the basal rate by 25-100%. Reassess after 15-30min.

What about the Fentanyl patch?

• Use only for stable, chronic pain in patients who are opioid tolerant, getting regular opioids > 1 week, and have requirement of at least 60mg morphine equivalent/day

• Use the following table based on the patients previous 24 hour opioid dose (if not on morphine, convert to morphine equivalent)

• Don’t increase more than every 3 days

Fentanyl patch conversion

oral 24 hour Fentanyl patch

morphine initial dose

(mg/day) (mcg/hr)

30-59 12

60-134 25

135-224 50225-314 75

315-404 100

Don’t forget about constipation!

• Tolerance eventually develops for all side effects except constipation

• “The same hand that writes the opioid, writes the stool regimen”– Colace AND something for motility (senna)

SCHEDULED (not PRN)…write “hold for loose stool”

– Also add a PRN (lactulose, miralax)

Conclusion

• Treat pain

• Know your pharmacology

• Get to know your pharmacist

• Consult the palliative care service for help with pain and symptom management AND for….

Reasons to consult the Palliative care service

• Symptom management• Help with complex decision making and

determining goals of care– Patients with prolonged LOS without improvement

who have poor prognosis

– Patients with frequent ED visits/admissions for same diagnosis

• Help with educating pts/families about hospice