Opioid Overview: Know What to Use and When

Patients with cancer can experience immense pain, and it is crucial that oncology nurses know how to effectively — and safely – manage that pain.

“Pain management is both an art and a science. You really have to see how the patient is doing. How are they tolerating the opioids?” said Jeannine Brant, PhD, APRN, AOCN, FAAN, oncology clinical nurse specialist, director and lead scientist at the Billings Clinic, Collaborative Science and Innovation. Brant recently led a presentation on opioid use at the 2020 ONS Bridge virtual conference.¹

Morphine

Brant said that morphine is really, “the gold standard for comparison for all opioids,” because it is inexpensive and can be given orally, rectally, as an immediate release or controlled release liquid, and can even be administered directly into the spine.

Morphine has 2 metabolites (byproducts of the body breaking down the drug) — m3G and m6G. Nurses should be aware that for patients with kidney issues, m3G and m6G accumulate in the body and can cause adverse events (AEs) such as neurotoxicity, nightmares, hallucinations, or over sedation.

The opioid is not completely off the table for patients with renal insufficiency, but clinicians should adjust the dose appropriately.

Oxycodone

Oxycodone — which is primarily administered orally, sometimes combined with acetaminophen – is another common and versatile opioid option for patients with cancer.

Oftentimes, patients who experience AEs from morphine will switch over to oxycodone. However, clinicians should be cautious when they are combining oxycodone and acetaminophen.

“We have to be careful of [combining the drugs] because we should limit acetaminophen to even less than 4 [doses] a day. Oftentimes, the limits are lower,” Brant said. “So many times, giving pure oxycodone and acetaminophen on the side is some of the best ways to control pain, even though it has an active metabolite.”

While oxycodone is efficacious and has a tolerable AE profile, nurses and other providers should also remember that it may pose a greater risk for patients with substance use disorder.

Fentanyl

Finally, fentanyl is a drug that has various mechanisms, depending on how it is administered.

For example, a transdermal patch can take up to 12 hours to start working, because the drug has to pass through the patient’s subcutaneous tissue and saturate the tissue. “Then it finally starts working 12 hours later, and lasts about 72 hours,” Brandt said. “For some patients, however, you have to apply it every 48 hours because they really drain that patch more quickly.”

Clinicians can also give fentanyl orally through the patient’s transmucosal membrane. That method had a quick onset — about 5 to 10 minutes, according to Brandt, who explained that fentanyl is absorbed through the fat or liquid membrane in the mouth.

Intravenous fentanyl also is quick to work, though nurses must remember that whichever fentanyl administration is chosen, it likely will take longer to have an analgesic effect in patients who are obese, because the drug has to saturate fat tissues.

Reference

• Brant J. All about opioidsL calculations and conversions. Presented at: 2020 ONS Bridge Annual Conference Sept. 8, 10, 22, and 24, 2020. Accessed Sept.22, 2020.