How To Effectively And Safely Transition One Mode Of Analgesia To Other Mode

1. How To Effectively And Safely Transition One Mode Of Analgesia To Other Mode Prof. Krishna Boddu . MBBS, MD, DNB, FANZCA, MMEd University of Texas Health Sciences at Houston, Texas, USA University of Western Australia, Perth, Australia Director, Regional Anaesthesia, Royal Perth Hospital, Perth, Australia

2. Clinical Situations Requiring Transition from One Mode of Analgesia to Other • Patient on Oral Pain medication – Now NPO • Post-Op patient On IV meds. Now on regular diet. • Regional (Epidural/ nerve blocks) to other mode • Drug interaction Eg. Started on Refampin • Drug diversion Interventional IV, IM, Sub Q PO/ NG Tube Other Activity PAIN NPO Status Tolerance

3. Basic Principles of Transition Clear plans for transition - essential Information from Patient and Charts Information from Text Books Details of all the Analgesics in use Bioavailability, Max dose, Equipotency & interactions Names of the drugs Onset, duration of action & peak effect Routes of administr Dose, Freq, 24h use Wash in & wash out curves Pharmacodynamics Always: Optimal Non-opioid Meds

4. Basic Principles of Transition Classify Medications As Opioids Non-Opioids How long the patient is on these? Estimated Opioid Equivalence available for some Convert 24 hour dose to IV MSO4 Equivalent Local Anesthetic based analgesia poses challenges

5. 1. On PO Pain meds – Now NPO Scenario 1: For back pain, for several months patient is on -100mg of MSContin PO Q8h & -30mg MSIR Q 4h PRN (uses approx 90mg/day) -100mg Pregabalin Q8h for neuropathic pain How to transition to IV PCA? What are the steps? 390mg PO MSO4 in 24h (Actual) = 130mg IV MSO4 in 24h (Estimated) Per hour IV Morphine use= 5.41mg (Estimated) Will pt be happy with 1mg dose with LOI 5 min? (She could get 12mg/h = 288mg MSO4 IV in 24h) NO Might be OK During the Day For Sure She will have Disturbed Sleep For Sure She will wake up with Severe Pain WHY?

6. 1. On PO Pain meds – Now NPO Transition is an Art of Science You Convince Patient That The Amount of Medication Available For Her Is Way More Than She Was Taking At Home to Cover Her Pain. Now, Patient Requests for Sleeping Pills. Just because you are giving IV Pain Medication that too plenty available does not mean that you will be able to provide better pain control 1-2mg/h MSO4 IV basal on PCA would be better than introducing sleeping pills. What About Pregabalin?

7. 2. IV Pain meds to Oral Scenario 2 (Surgeon’s request) : Post op pain pt on IV PCA Hydromorphone & history of heroin abuse ready for transition to PO pain meds. 24 hour consumption of HM is 30mg. How to transition to PO meds? What are the steps? 30mg IV Hydromorphone in 24h (Actual) = 150mg IV MSO4 in 24h (Estimated) (based on equi-potency) 600mg PO MSO4 in 24h (Estimated) (based on BA) Will you be comfortable to give 600mg PO Morphine to a pt with history of drug abuse? NO Will you let the pt suffer? What will be your concerns? How to handle this situation? WHY?

8. 2. IV Pain meds to Oral We can not let patient suffer with pain irrespective of his social, racial, criminal backgrounds. Our main concern: How to transition IV to PO and wean off this patient from PO? Who will priscribe large opioid doses at the time of discharge? Follow the rules of managing opioid tolerant patient. • Optimize non-opioid analgesics + Tramadol • Start on alpha 2 agonists clonidine (PO/ TD) • NMDA modulators (Ketamine PO/ IV), • Lidoderm 5% patch • Oxycodone ER with Nalaxone PO 60mg Q8 + 5-10-15 mg Oxynorm PRN Q4h

9. 2. IV Pain meds to Oral Books say 1.2mg – 2mg Oxycodone = 1mg IV MSO4 Rationale for Oxycontin & Oxynorm doses Oxycodone Bioavailability 80% Oxycodone Bioavailability 50% 150 mg IV MSO4= 180 mg Oxycodone 150 mg IV MSO4= 300 mg Oxycodone Give 60% as long acting 60mg Q8h = 120mg 70mg Q8h = 210mg Remaining dose as PRN in 6 divided doses Q4h 180mg – 120mg = 60mg 60mg/6 = 10 mg (Order 5-10-15 mg PRN Q 4h) 300g – 210 mg = 90mg 90mg/6 = 15 mg (Order 10-15-20 mg PRN Q 4h)

10. 3. Transition from Epidural analgesia to IV/PO Epidural Solution Opioid + Local Anesthetic Epidural Solution 8ml/h (LA+ 5mcg Hydromorphone/ml Local Anesthetic Non-Lipophilic Opioids 1000 mcg IV= 100 mcg Epidural= 10 mcg Spinal Epidural 50 mcg/h (1200 mcg/day) = 12000 mcg/day IV Per day 12 mg IV HM = 55 mg IV MSO4 This can be easily covered with PO 400 mg Tramadol, 4 g Paracetamol, NSAIDS per day Difficult to convert to Opioid Equivalence, so use PRN Opioid Medication to cover Lipophilic Opioids 1000 mcg IV= 500 mcg Epidural= 250 mcg Spinal My Transition Orders Stop Epidural after giving first dose of PO Oxycodone 10mg Paracetamol 1g Q6h (PO/ IV) Tramadol 100 mg Q 6h (PO/ IV) NSAID (Celebrex 200 mg BD) / Parecoxib 40 mg Q 8 IV PRN Oxycodone 5-10-15 mg Q 3h (Mild-moderate-Severe) If Transition Is Smooth, After 4 h Remove Epidural Catheter

11. 4. Transition from Nerve Catheter to IV/PO Remember that it takes only 1-4 hours for block to disappear after stopping infusion Local Anesthetic My Transition Orders Stop infusion after giving first dose of PO Oxycodone 20mg Paracetamol 1g Q6h (PO/ IV) Tramadol 100 mg Q 6h (PO/ IV) NSAID (Celebrex 200 mg BD) / Parecoxib 40 mg Q 8 IV PRN Oxycodone 5-10-15 mg Q 3h (Mild-moderate-Severe) If Transition Is Smooth, After 4 h Remove Nerve Catheter Difficult to convert to Opioid Equivalence, so use PRN Opioid Medication to cover

12. 5. Drug interaction Eg. Refampin Complete loss of analgesia possible when pt started on Refampin With in a day after starting Refampin Oxymorphone is least influenced by enzyme induction Do we need to let patient suffer with pain before transition to other? Close and through followup of APS is required to implement this Consider optimal non-opioid anagesics + Regional Analgesia BE AWARE OF ENZYME INHIBITORS & INDUCERS How to avoid this? • In paper form: APS signs to let us know • In Electronic Orders: APS as pain medication and build drug interaction list of your choice

13. Decrease dose interval Analgesia fine tuning First 48h postop or any pain at rest or pain all the time Pain Questions Pain on activity Give PRN medication (PRN on PCA, PCEA) Give meds ATC (basal on PCA, PCEA) Pain not down to satisfactory level Pain decreased to satisfactory level Relief not lasting long enough Only on waking up in the morning Night time basal or dose Increase PRN dose Consider adjusting ATC dose to keep 60% of 24 hr requirement as ATC Requiring frequent PRN > 4 times/ day.

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