Opioids

Clinical Case 78 YO F with no PMH was admitted to the hospital for newly diagnosed pancreatic cancer. The patient has been requiring large amounts of Dilaudid (hydromorphone) IV during (totaling 8.1mg / 24 hrs). The patient is ready for discharge. What oral regimen should you send her home on?

Objective Learn some key opioid facts Learn to convert common inpatient opioids to common outpatient opioids

Key opioid Facts Renal Failure – Avoid morphine Fentanyl patches Choose: Fentanyl or Dilaudid Fentanyl patches Cachexia, body temperature, delay in onset Short vs Long Acting Dilaudid = Short only Morphine = Short or long (MS Contin) Constipation Avoid morphine in patients with renal failure or insufficiency. Morphine’s toxic metabolites are renally cleared, thus this is a bad option for these patients. Fentanyl is the best option, followed by dilauid. (People tend to not know what it looks like when people have elevated levels of toxic opioid metabolities. What you will see firs tis confusion, followed by muscular tics, then seizure/comas.) Fentanyl Patch – Absorbed via fat. Watch for placement location. Also patient’s who are cachectic may not absorb the medication at all. Will give a bolus depending on pt’s temperature (Watch in patient’s who may have fevers) Takes about 12-24 hours to have an effect on patients The only side-effect of opioids to which patients do not build a tolerance is constipation. Remember to start your patients on a bowel regimen when starting these meds

Opioid Conversion Chart IM/IV PO Morphine 10 30 Dilaudid 1.5 7.5 Fentanyl 100mcg/24h patch = 200mg PO morphine Simple conversions 1mg IV Hydromorphone = 20 mg PO morphine 1mg IV Hydromorphone = 5 mg PO hydromorphone 30mg PO Morphine = 1.5mg IV Hydromorphone ***** Please refer to a more formal chart for further conversion. I will be sticking to commonly used medications here.

Chronic Pain Opioid Conversions Total Amounts Convert Cross-Tolerance? Choose appropriate PO PRN’s/breakthrough pain Bowel regimen Tally 24 hour use of all opioids (PO and IV) Convert opioid amounts to equivocal doses of PO medication Evaluate need for cross-tolerance reduction (10-30% reduction in total dose)*see note bellow If capable of using MS Contin divide total dose of PO morphine by 2 to determine BID dose, or if only able to do shorter acting opioids (IE Oxy IR, Morphine Elixir, or PO dilaudid) divide by 6 for q4h dosing Provide PRN’s for breakthrough pain that can total 50-100% of patient’s total dose in a 24 hours period. Remember to start a bowel regimen *Cross tolerance – patient’s who are on one opioid will respond stronger to another if switched (even with equivocal dosing). For example, if someone is taking 1 mg of IV dilaudid, 20 mg of PO morphine would have a stronger response in that patient. For that reason, cross tolerance reduction of 10-30% should be done.

Clinical Follow up 8.8 mg IV Dilaudid to PO morphine = 8.8 x 20 = 176 mg PO Morphine Cross tolerance? YES! Reduce by 15% PO Morphine = 150mg MS CONTIN = BID Dosing. 150mg in BID dosing = 150/2 = 75mg MS Contin BID Breakthrough dosing = minimum of 50% total = 150 * 0.50 = 75mg / day 75mg divided into q4h dosing = 75 / 6 = ~12 mg q4h PRN Pt taking 8.8mg IV Dilaudid-> convert to PO morphine -> (20:1 ratio) equivalent to 176 mg po morphine As this pain is due to cancer, which will be a chronic pain for this patient, I will want to convert the patient to a long acting medication. I will use MS CONTIN. As I am switching from Dilaudid to morphine I will reduce dose for cross tolerance (15% reduction = ~25mg morphine) -> Thus will require ~ 150mg po morphine daily As MS CONTIN is a BID medication, 75mg MS Contin BID would be ideal dosing for this patient. Breakthrough dosing would be at least 75mg of morphine per day (50% of total day’s dose). Will divide by 6 to do q 4 hour dosing. 75/6 = 12.5 mg per dose – This can be written for as morphine elixir. Or as 15mg of Immediate Release Morphine

But that’s so many numbers! How can I keep track of all that?!

Don’t you worry little intern/resident, the internet is here to help!

Global RPH http://www.globalrph.com/narcoticonv.htm This is a great resource, but does not take the thinking out of your conversions. This, however, can help you if you don’t have an opioid conversion chart handy.

And if you have any questions… Please contact your local Palliative Care / Pain specialist.