Topic: Information about Cancer Pain Management- Part II- the Use of Opioids.
Pharmacological Management: the use of opioids(ie: codeine, oxycodone, hydrocodone,morphine,hydromorphone,fentanyl and methadone).
2.Opioids are the first-line and widely used for moderate to severe chronic cancer pain.Due to the side effects such as constipation, nausea,sleepiness or drowsiness,mental confusion,itching,perceptual disorders,hallucinations etc.are common in the course of long term use ,choosing the appropriate opioid and route of administration will prevent or minimize the problem. Here are some of the information on this topic.
Most patients start with oral administration of acetaminophen and hydrocodone or oxycodone combination formulations such as Vicodin,Lorcet,Norco,Percocet and Tylox etc or ibuprofen with hydrocodone(Vicoprofen) or aspirin with hydrocodone (Damason-P) every 4-6 hour and adjust upward;or morphine such as MS Contin for twice daily use or Avinza extended capsule for once daily use. For breakthru pain morphine oral solution can be used every 1-2 hours as needed.
Morphine is the standard for comparison for opioids; multiple routes are available as tablets , rectal suppository,enteral liquid and parenteral infusion such as in PCA dosage form given intravenously.
For patients with difficulty in swallowing or oral mucositis or severe nausea, SOME of the modified release morphine capsules(eg.Avinza,Kadian) can be opened and sprinkled on food without changing the delivery characteristics (ie:the frequency of administration-once or twice daily)through feeding tube. Ask your doctor or pharmacist when in doubt about which one can be used in this way. In general, opioids controlled-release , sustained- release or extended- release dosage form (ie: tablet,capsule ) should never be crushed because of acute toxicity and should not take with alcohol because alcohol can dissolve the matrix in which the drug is embedded for modified-release.
Hydromorphone(Dilaudid) is more often used in intravenous such as in PCA (patient- controlled analgesia) dosage form or subcutaneous administration but it also comes as oral dosage forms such as liquid,immediate release tablet,extended release tablet(Exalgo) for once daily use.For patients have renal insufficiency or relatively high doses are needed, hydromorphone is preferred.
Fentanyl can be given as IV bolus intravenously for almost immediately relief of pain as compare to morphine,IV bolus,which may require 15-30 minutes to reach the peak onset of pain relief. Fentanyl also comes as transdermal system(patch) for topical use of up to 48-72 hours; as oral lozenge (ACTIQ), sublingal tablet(Abstral)buccal tablet (Fentora) and a buccal soluble film (Onsolis) for rapid onset of cancer-related breakthru pain relief. The Fentanyl patch may be preferred over orally administered opioid for patients of poor GI absorption or having difficulty in swallowing,or if constipation or renal insufficiency is an issue.
Experience in the use of Levorphanol is very limited in the US,but it should be viewed as another option for the treatment of cancer pain.
Methadone is challenging to use and clinicians should seek assistance from a consultant before prescribing methadone.It has the highest risk of among opioids of overdosage.
Codeine and Meperidine(Demerol) are not preferred for cancer pain management .
Rectal absorption of opioids is variable and the relative potency and effectiveness are difficult to predict .
Intrathecal and intraspinal administration(ie:epidural) of opioids yielded better pain control and fewer side effects.
There is no evidence that anyone of the commonly used,long-acting formulations (including morphine,hydromorphone,oxycodone , oxymorphine and fentanly) is more likely to be effective than any other.Selection usually is determined by the patient's prior experience with opioids,the doctor's experience,cost , availability and formulations.
Management of poorly responsive pain options such as opioid rotation(switching between opioids)required clinical judgment and should be based upon specific patient characteristics as well.- summarization of cancer pain management articles(May,2011) from uptodate.com .
For more info. about pain go to www.stoppain.org ,click the bottom left box"pain medicine" for more in depth information about pain management.(I did not read that much on this web site.but it looks like a good place to learn.)