A logical method for hospital-based pain treatment

Bob Arnold MD

Institute to Enhance Palliative Care

Objectives

• By the end of the session, participants should be able to:– Describe the various steps in determining

opiate orders– Describe the principle of equianalgesia and

perform the calculations

Objectives

• By the end of the session, participants should be able to:– Write initial PCA orders– Describe how to dose escalate in a patient

with more severe pain– Describe the major side effects of opiates

(if we have time!)

Objectives

• What do you want to learn?

Addiction fear

• Dependence

• Tolerance

• Addiction– Evidence for– Dealing with addiction in the hospital

• Pseudo addiction

Steps in Opiate dosing

• Calculate the previous days oral morphine equivalent

• Determine if the dose is adequate for the pain and dose adjust

• Determine the opiate that will be used and dose adjust for cross tolerance

• Determine the route the opiate will be given• Determine the dosing schedule• Determine breakthrough dose

Case 1

• Mrs Jones is a 63 year woman with back pain due to ovariancancer. At home she has been taking percoset 1-2 every 4 hours (8 day)In the ER, She got 3 mg iv hydromorphine over 3 hours and on the floor her pain is a 8/10. WHAT OPIATE SHOULD YOU USE?

Opiates• Opioids

– All opioid analgesics produce pain relief via interaction with opioid receptors in the brain/spinal cord and perhaps via peripheral opioid receptors

– The mu receptor is the dominant analgesic receptor, but other receptors play a role in analgesia for certain opioids

– There is no dose ceiling for opioids, only for acetaminophen in combination products

• Opioids are classified by their interaction with the opioid receptors– pure agonist (morphine, hydromorphone (Dilaudid ®)

oxycodone, codeine, meperidine, fentanyl)– mixed agonist-antagonist (Stadol ®, Talwin ®, Nubain ®)– partial agonist (buprenorphine)– pure antagonist (naloxone, naltrexone)

Opioids (cont)

Case 1

• You admit a patient with cancer-related chest wall pain. She is on MS Contin 15 mg bid with 5 mg prn q 3 hr. Last week, she called up herPCP who gave her percoset 1-2 q 4 hrs (she took 10 day) as well as started her on Oxycontin 10 two times a day. What should you do?

Calculate the previous days OME

• Since all potent opioids produce analgesia by the same pharmacological mechanism, they will produce the same degree of analgesia if provided in equianalgesic doses.

• Thus, there is little basis to say, “morphine did not work, but hydromorphone did work”. Such a statement generally means that non-equianalgesic doses were used.

EquianalgesiaCommon Conversions

• SEE PAIN CARD – EVERYTHING ON THE CARD IS EQUIPOTENT

• 10 mg IV MS = 30 po MS• 10 mg IV MS = 1.5 mg IV Dilaudid

• 30 mg po MS = 7.5 mg po Dilaudid®• 30 mg po MS = 30 mg po oxycodone **

Note: Conversions factors are only a rough guide to approximate the correct dose.

PAUSE & CalculateEquianalgesic Problem

• Calculate: What is the patient’s OME (15 mg MS Contin bid; 10 mg oxycontin bid; 10 percoset day and 6 MSIR (5 mg))

Determine the “new” OME dose

• Determine if the dose is adequate for the pain– Assess pain using a 1-10 scale– Fudge factors

• Activities of daily living• Adverse effect• Previous pain score

Opioid Dose EscalationAlways increase by a percentage of the present dose

based upon patient’s pain rating and current assessment

Mild pain 1-3/10

25% increaseModerate pain4-6/10

25-50% increase Severe pain7-10/10

50-100% increase

Determine the opiate that will be used

• Based largely on side effect profile

• Meperidine

• Morphine and renal failure

• Cross tolerance fudge factor– If changing opiate decrease OME 30-50%– BACK TO OUR CASE

Case 1

• You admit a patient with cancer-related chest wall pain. She is on MS Contin 15 mg bid with 5 mg prn q 3 hr. Last week, she called up her PCP who gave her percoset 1-2 q 4 hrs (she took 10 day) as well as started her on Oxycontin 10 two times a day. What do you estimate her OME will be? What opiate would you use

Determine route and dosing schedule

Ultra short

Short

Long

Short Acting Opioids

• Parenteral or Oral– morphine– hydromorphone

(Dilaudid ®)– meperidine (Demerol

®) – codeine

• Oral only– Oxycodone/Acetam or

NSAID– Hydrocodone/Acetam

or NSAID– Note: hydrocodone is

only available as a combination product.

• Oral dosing:– onset in 20-30 min– peak effect in 60-90 minutes– duration of effect 2-4 hours– Start with this for opiate naive– Can be dose escalated or re-administered

every 2-4 hours for poorly controlled pain as long as the daily Acetaminophen dose stays < 4 grams

Short Acting Opioids

Be careful with tylanol

• Current recommendations is less than 3 gm/day

• Vicodan ES has 750 mg

Parenteral Opioids• IV is the route of choice if

access is available– There is no indication for IM opioids– All standard opioids can be given SQ, by either

bolus dose or by continuous infusion

• More potent due to lack of first pass effect– Dose adjustment controversial

• IV or SQ bolus doses have a shorter duration of action that oral doses; typically 1-3 hours

• The peak effect from an IV bolus dose is 5-15 minutes– Fentanyl >Morphine

Parenteral Opioids

Dosing options

• PCA

• Long acting in concert with Breakthrough dosages

• Short acting “around the clock”

• PRN

PCA

• Theory– Patient controlled results in less opiate

delivered with same pain relief– Allows for a constant level of opiate rather

than peaks and valleys– ALL PCA’s ARE CONSTANT INFUSIONS

PCA

• Bolus– Morphine or Dilaudid– Q 15 minutes– Get a high drug level before start the pca– The amount it takes to control pain is more

than the amount it takes to keep one out of pain

PCA

• Patient controlled dosing– Remember that 10mg of morphine =1.5

hydromorphine– Constant infusions– Time interval– Hour lockout– Relative contraindications

Case 2

• You admit a 72 year old man with acute pancreatitis. His pain is 9/10. What should you do? (He can not take po)

Converting to oral dose

Case 3- A patient with chronic low back pain is admitted with an exacerbation and put on a PCA. Over the next 48 hours, the patient used an average of 6 mg hour morphine and this controlled her pain.

• What is the patient’s OME?

• Is the pain well controlled?

Long act with BKT

• Long acting opiates allows a constant opiate with fewer doses.

• Long Acting - 2/3-3/4 of total daily dose• All provide 8-12 hours of analgesia• All provide onset of analgesia within 2 hours• All can be dose escalated every 24 hours

Long Acting Opioids• Oral

– MS Contin ®– Kadian ®– Avinza ®– Oramorph SR®– Oxycontin®– Opana (oxymorphine)– methadone

• Transdermal– Fentanyl Patch

(Duragesic®)

Long act Morphine-oxycodone• No clear benefit of one product over another

– MS Contin/Avinza/Kadian/Oramorph contain morphine– Oxycontin contains oxycodone (70/30)– No difference in toxicity; No difference in addiction potential

• Oxycotin/Oramorph/MS Contin must be taken intact—they cannot be crushed; they do not fit down GI tubes.

• Kadian/Avinza pellets can go down large bore feeding tubes

Transdermal Fentanyl• Slow onset of action: 13-24 hours

– Duration of action: 48-72 hours

• Should only dose escalate q 3 days– Fentanyl stays in circulation for up to 24

hours after patch removal

• Place on hairless, non-irradiated skin

• No ceiling dose

Conversions from/to Transdermal Fentanyl

(Duragesic®)• Equianalgesic conversion formula

– 24 hour total dose of oral morphine, divided by 2 = dose in micrograms of transdermal fentanyl

– Iv/hr dose= dose in mcg of transdermal fentanyl; – Example:

• MS Contin® 30 mg q 12 = 60 mg MS/24 hours• 60 divided by 2 = 30; rounded to one 25 ug Fentanyl

Patch• SO IN OUR PATIENT WHAT FENTANYL DOSE

WOULD YOU USE

Breakthrough Pain• Patients on any long-acting med always need a

second, short-acting med, available for breakthrough pain

• something they can take at least every 4 hours, preferably less

• Guideline, dose of breakthrough opioid should be: 10-20% of 24 hour dose of analgesics and made available

q2 hours

• FOR OUR PATIENT ABOVE WHAT BKT DOSE WOULD YOU USE

Other dosing schedules

• Short acting “around the clock”

• PRN

Case examples

• 50 year old woman who comes in with severe pain due to a metastatic compression fracture

• At home she is on oxycontin 10 mg bid, a 25 mcg fentanyl patch and 9 oxycodone 10mg/day.

• Her pain is a 8/10• What would you do?

Steps in Opiate dosing

• Calculate the previous days oral morphine equivalent

• Determine if the dose is adequate for the pain and dose adjust

• Determine the opiate that will be used and dose adjust for cross tolerance

• Determine the route the opiate will be given• Determine the dosing schedule• Determine breakthrough dose

Case examples

• You are admitting a 75 year old woman with increasing pain because of breast cancer with invasion into the pleural wall. She has been on oxycotin 30 mg bid and percoset 1-2 every 4 hours for two days (taking roughly 10 a day). Her pain is a 8/10. What should you do?

Steps in Opiate dosing

• Calculate the previous days oral morphine equivalent

• Determine if the dose is adequate for the pain and dose adjust

• Determine the opiate that will be used and dose adjust for cross tolerance

• Determine the route the opiate will be given• Determine the dosing schedule• Determine breakthrough dose

Case examples

• You are asked to see a post-surgical patient due to “pain.” She is a 63 year old man who has cervical cancer. She was admitted for a SBO and had a venting gastrostomy. Shee says that his pain control is fair as long as they give him his medicine.

Case examples

• In the last 24 hours she has gotten 50 mcg fentanyl patch, 8 percoset, 10mg iv morphine and 2 mg iv hydromorphine. Her pain is his chronic mid-abd pain, although there is also some post-operative pain.

Steps in Opiate dosing

• Calculate the previous days oral morphine equivalent

• Determine if the dose is adequate for the pain and dose adjust

• Determine the opiate that will be used and dose adjust for cross tolerance

• Determine the route the opiate will be given• Determine the dosing schedule• Determine breakthrough dose

Dosing opiates in the actively dying patients

• You are asked to see a patient admitted from the ER who is actively dying and CMO. He was not on any opiates at home. He seems to be moaning and has a respiratory rate of 45. What should you do?– Bolusing every 15 minutes– Using a drip based on bolus amount

Opioid Adverse Effects

Common UncommonConstipation Bad dreams / hallucinations

Dry mouth Dysphoria / delirium

Nausea / vomiting Myoclonus /seizures

Sedation Pruritus / urticaria

Sweats Respiratory depression

Urinary retention

Constipation

• Common to all opioids

• Opioid effects on CNS, spinal cord, myenteric plexus of gut

• Easier to prevent than treat

Constipation . .

• Diet usually insufficient

• Bulk forming agents not recommended

• Stimulant laxative– senna, bisacodyl, glycerine, casanthranol,

etc.

• Combine with a stool softener– senna + docusate sodium

. . Constipation

• Prokinetic agent– metoclopramide, cisapride

• Osmotic laxative– MOM, lactulose, sorbitol

• Other measures

Nausea / Vomiting . . .

• Onset with start of opioids– tolerance develops within days

• Prevent or treat with dopamine-blocking antiemetics– prochlorperazine 10 mg q 6h– haloperidol 1 mg 6h– metoclopramide 10 mg q 6h

. . Nausea / Vomiting

• Serotonergic agents also are effective

• Alternative opioid if refractory

Sedation . .

• Onset with start of opioids– distinguish from exhaustion due to pain– tolerance develops within days

• Complex in advanced disease

. . Sedation

• If persistent, alternative opioid or route of administration

• Psychostimulants may be useful– methylphenidate 5 mg q am and q noon,

titrate– Less common-Aricept/Modafinil

Delirium . . .

• Presentation– confusion, bad dreams, hallucinations– restlessness, agitation– myoclonic jerks, seizures– depressed level of consciousness

• Disorder of attention– CAM

. . Delirium

• Rare, unless multiple factors contributing, if – opioid dosing guidelines followed– renal clearance normal

• Treat – Rotate opiate– Look at other medicines– Haldol

Respiratory Depression . . .

• Opioid effects differ for patients treated for pain– pain is a potent stimulus to breathe– loss of consciousness precedes respiratory

depression– pharmacological tolerance rapid

Questions

• Call Palliative care with questions– Magee -8510– Winnie Teuteberg– Elizabeth Weinstein’s clinic-641-4530