Palliative Prescribing - Pain

Transcription

1 Palliative Prescribing - Pain LAURA BARNFIELD 21/2/17 Aims To understand the classes of painkillers available in palliative care To gain confidence in counselling regarding opiates To gain confidence prescribing opiate analgesia for different routes of administration To understand the concept of total pain 1

2 WHO Pain Ladder Paracetamol Don t underestimate this humble drug! Great adjuvant to Codeine and Tramadol Well-tolerated Oral, rectal and IV routes Dose adjustment for low weight- consider 1g tds/bd 2

3 NSAIDs Particularly useful in cancer patients with bony metastatic disease (also consider referral for radiotherapy or asking hospice for advice regarding bisphosphonates if struggling to control) Consider an NSAID with a lower GI risk Ibuprofen or Naproxen and consider PPI cover Avoid in patients on steroids, caution with SSRIs, renal failure Weak opiates Consider in combination with Paracetamol but think about cost Co-Codamol 15/500 very expensive Consider opioids if intolerable side effects 3

4 Neuropathic agents Effective for neuropathic pain, but not for simply poorly controlled chronic pain Consider local prescribing guidance for which to start- which would you choose? Neuropathic agents Treatment Pros Cons Amitriptyline (TCA) 10mg-150mg Good NNT , can help with mood or bladder spasm, Dry mouth, sedation, falls risk in elderly- postural hypotension 20% stop due to side effects Gabapentin mg tds increasing to 3600mg in divided doses according to response Pregabalin 25-75mg bd increasing to 300mg bd studies on mg daily NNT , NNH 25 Cheap NNT 7.7, relatively well tolerated, bd dosing easier than Gabapentin s tds Reduce dose in renal impairment, takes some time for dose titration Sedation, dizziness, ataxia On patent for neuropathic pain - in GP setting meant to use Lyrica, which is very expensive Dose-response gradient 600mg better than 300mg daily but caps on doses in GP setting Sedation, dizziness, ataxia In some areas Lidocaine patches might be used but these are expensive and only licensed for post-herpetic neuralgia Duloxetine (SNRI) 30-60mg od NNT 5.2, better tolerated than TCAs Delay to effect, nausea, dizziness, drowsiness, sweating, dry mouth 4

5 Strong opiates WHY DON T PATIENTS WANT TO TAKE THEM? 5

6 Side effects Constipation Postural hypotension Dry mouth Biliary spasm Nausea Bloating Hallucinations Respiratory depression Tolerance Drowsiness Dependence Bradycardia Tachycardia Vertigo Euphoria Mood changes Sleep disturbance Urinary retention Sweating Flushing Rash Pruritus Commencing opiates Good practice is to prescribe for anticipated side effects by also supplying laxatives (such as Laxido) and antiemetics (such as Metoclopramide) Stop weak opiates do not prescribe multiple mixed opiates Consider preferred route 6

7 Conversions Analgesic Route Dose Morphine PO 10mg Codeine PO 100mg Tramadol PO 100mg Oxycodone PO 5-6.6mg Morphine IV/IM/SC 5mg Diamorphine IV/IM/SC 3mg Alfentanil SC 0.3mg If someone has been taking regular full-dose Codeine, how much Morphine would this be equivalent to? Background need Calculate appropriate dose from previous opiates (or from giving Oramorph 5-10mg every 4hrs as needed) over 24hrs Oral morphine preparations should be prescribed 12hrly (Zomorph, MST) so divide 24hr dose by 2 for slow-release morphine dose for background relief 7

8 Breakthrough need Divide 24hr morphine dose by 6 to establish breakthrough dose If awkward number, always round down This can be given 2-4hrly at home in the form of immediate-release morphine (Oramorph, Sevredol) If using more than 3 breakthrough doses in 24hrs regularly, consider increasing background analgesia (usually by 30-50%, dependent on breakthrough use) Opiate Maths (1) Kathy is 73 with metastatic breast cancer. She has been taking regular Co-Codamol 30/500 TT qds but is still reporting breakthrough pain Please calculate an appropriate starting dose of Morphine for Kathy, with both background and breakthrough analgesia. Show your working. Beryl is 68 with oesophageal cancer and has been taking Morphine 60mg bd, and 4x 20mg breakthrough Oramorph in 24hrs. Please increase her background analgesia as appropriate, and calculate her new breakthrough dose. Show your working. 8

9 Alternatives to Morphine WHY MIGHT YOU USE OXYCODONE, DIAMORPHINE, ALFENTANIL, BUPRENORPHINE OR FENTANYL? Alternatives to Morphine Oxycodone (Oxycontin/Oxynorm, Longtec/Shortec) switch to if intolerable side effects, or reached dose-effect ceiling. Better in renal failure. Diamorphine- used sub-cut when large doses required- comes as powder so can be made up to a small volume at higher concentration Alfentanil- used in severe renal impairment- unlikely to be used in the community setting Buprenorphine- for patients who prefer/require transdermal route for weak opiate doses Fentanyl- for patients who prefer/require transdermal route for strong opiate doses 9

10 Opiate Maths (2) Hugo has been taking Zomorph 80mg bd and in the last few days is using 2x breakthrough doses of 25mg Oramorph. He is getting significant side effects of hallucinations, jerkiness but is still in pain. What do you want to know? What will you prescribe? Jennifer is using a 50mcg Fentanyl patch that she has started just 10 days ago. The hospital did not supply her with breakthrough analgesia and she is reporting pain mostly in the evenings. What would you prescribe? Subcutaneous infusions CSCI (continuous subcutaneous infusion) is the preferred method of administration of medication at the end of life because of ease of access, steady dose and loss of oral route. Why do we not use Fentanyl patches routinely in this situation? Morphine and Oxycodone are the most commonly used analgesics. If someone is using one of these and loses their oral route, continue with the same medication in the infusion. The subcutaneous dose is found by calculating the oral dose over 24hrs (may include breakthrough doses) and dividing by two 10

11 Opiate Maths (3) Kenneth has been taking 100mg Zomorph bd for several weeks for pain from his prostate cancer. He is reaching end of life and now unable to swallow. In the last 2 days he has averaged 3x breakthrough doses in 24hrs of 30mg Oramorph. What would you put in his CSCI? Show your working. What would you prescribe for breakthrough use? Ethel has been taking 35mg bd of Oxycontin and averaging 2 breakthrough doses of 10mg Oxynorm daily for her metastatic ovarian cancer. She can no longer tolerate oral medications as she has developed bowel obstruction. What would you put in her CSCI? Show your working. What would you prescribe for breakthrough use? Fentanyl Patches at End of Life If a patient has a Fentanyl patch on already LEAVE THIS IN PLACE AND CHANGE AS USUAL A CSCI of Morphine or Oxycodone can be added to a Fentanyl patch for quicker titration of analgesic need please ensure this is an adequate dose. Double the PRN dose would be a good place to start. Do not increase the patch in the last days of life 11

12 Opiate Maths (4) William is 84 and dying from pancreatic cancer. He has been wearing a Fentanyl patch at 100mcg. The dose was last increased 4 weeks ago. He is now unable to take oral medication and is appearing in pain. What would you prescribe for background pain relief? What would you prescribe for breakthrough? Show your workings. Total Pain Assessment This is a useful tool to consider your patient holistically- particularly when they have rapidly escalating analgesic requirements or difficult to manage pain that doesn t respond to traditional analgesia. Consider the patient s pain from Physical, Psychological, Spiritual and Social perspectives- is there anything you (or another professional) can do to reduce their pain and distress other than increasing opiates? Example- 49yr old hospice patient with lung cancer and treatmentresistent hypercalcaemia 12

13 Conclusion You are not restricted to using just opiates in palliative careconsider adjuncts, and for bone metastases in particular alternatives are more effective. Always ask does the pain get better when you take your opiates? Write all calculations longhand and consider getting someone else to check them before prescribing. If in doubt, seek help, and always round down. If reaching end of life, convert to a CSCI using the opiate they are already using and never mix opiates Keep the Fentanyl patch on and replace as usual, but do not use this to rapidly titrate analgesia Consider a total pain assessment if struggling to control a patient s pain References Pain and Symptom Control Guidelines Greater Manchester Strategic Clinical Network, revised August 2016 Palliativedrugs.com NICE evidence Pain and Opiate Analgesia 13