New drugs available for Palliative Care

[cougarnurse]

Thought this was appropriate: New Drugs for the Palliative Care Setting - Oncology Nursing News

A review of new drugs appropriate to the palliative care setting and the implications of their use was offered by Mary Lynn McPherson, PharmD, BCPS, CDE, professor at the University of Maryland School of Pharmacy during the Annual Assembly of the American Academy of Hospice and Palliative Medicine. Dr McPherson discussed the new drugs approved by the Food and Drug Administration (FDA) in 2008, their approved indications, unapproved uses of the medication, and common adverse effects and drug interactions. But beyond the clinical considerations of the medications, Dr McPherson also discussed the “burden-to-benefit” ratio of each drug, which helped attendees to better understand assessing such factors as side effects and cost.

Dr McPherson also covered several drug issues that are (or should be) on nurse's radar screens. Tramadol, for example, remains a controversial drug with its potential for physical and psychological dependence. The US Drug Enforcement Agency has had tramadol on its list of “Drugs and Chemicals of Concern” since 2004, noted Dr McPherson, and while the drug is not regulated as a controlled substance at the federal level some states have classified it as schedule IV or otherwise monitor its use.

The notion that promethazine (Phenergan) enhances the analgesic effect of opioids was also explored and dismissed. One study, she noted, showed that promethazine actually increases sensitivity to pain and the amount of opioid needed for pain relief. Sedation is not pain relief, Dr McPherson pointed out, and sedation can increase opioid risk.

Propoxyphene has been associated with 50 000 deaths in the United States in the past 50 years, Dr McPherson told the audience, and was a factor in 5.6% of drug-related deaths in US from 1981-1999. Nevertheless, propoxyphene is widely used in the United States (while it is banned in the United Kingdom and rarely used in Canada). An FDA advisory committee that met in January 2009 recommended that the FDA discontinue marketing these products. (Editor's note—On July 8, the FDA announced it had decided to not remove propoxyphene from the market, but did require changes to the package warnings regarding overdose. The FDA also announced the start of further studies on propoxyphene use.) As little as 6 to 15 tablets or capsules of the drug can be lethal, Dr McPherson indicated at the meeting, especially when it is used with alcohol or central nervous system depressants. Propoxyphene plus acetaminophen doesn't offer additional pain relief as compared to acetaminophen alone, she concluded.

Another safety issue presented in the session concerned the development of tamper-resistant opioids to cut down on their misuse. Persistent, serious OxyContin abuse led to a reformulation of the tablet and a meeting of the FDA's Drug Safety and Risk Management Advisory Committee in May 2008 to discuss that reformulation. That meeting generated more questions than consensus on the efficacy of the reformulation. Also under development is Embeda (Alpharma), an extended-release morphine with a separate naltrexone core. When the drug is swallowed, the pain reliever alone is absorbed by the body; when the drug is crushed, chewed, or dissolved, the naltrexone core is released, blunting the high delivered by the opioid.

A final caution raised by Dr McPherson concerned methadone and its potential to prolong the rate-corrected QT interval (QTc), leading to torsade de pointes. The caution is based on an article by a multidisciplinary expert panel in the Annals of Internal Medicine (Krantz MJ, et al. Annals Intern Med. 2009;150:387-395), which presented 5 recommendations to promote cardiac safety. These include 1) informing patients of the methadone/arrhythmia risk; 2) asking patients about any history of structural heart disease, arrhythmia, and syncope; 3) obtaining a pretreatment electrocardiogram for all patients measuring the QTc interval and a follow-up electrocardiogram within 30 days and annually and obtaining additional electrocardiography if the methadone dosage exceeds 100 mg/day or if patients have unexplained syncope or seizures; 4) discussing the potential risks and benefits with patients and increasing monitoring when QTc interval is between 451ms and 499ms, and considering discontinuing or reducing the methadone dose, eliminating contributing factors, or using an alternative therapy when the QTc interval is >500ms; and 5) being aware of interactions between methadone and other drugs that possess QT interval-prolonging properties or slow the elimination of methadone.

“All healthcare providers are somewhat more aware of new drug developments than in the past because we have so much electronic media—in addition to print—sharing this kind of news,” Dr McPherson said in a postconference interview. “Also, the FDA has shown increased activity in publicizing important drug information, such as new drugs, and even more importantly, public health advisories. Many pharmacy providers are now sharing breaking drug news by both electronic and print media.”

Dr McPherson suggested the best way to stay informed is pay attention, and tune in to information sources. “Anyone can navigate to the FDA webpage and click on Drug Information (www.fda.gov/cder/news/pubpress.htm) to learn about what's new in drug therapy,” she said. “And in today's era, most drug therapy news touches on what we do in hospice and palliative care. Practitioners can sign up for daily news bulletins, and nurses can work with their pharmacy provider to request regular drug updates.”

From the September 2009 Issue of ONN