| Archives
2002
March
February
January
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CA
Breakthrough Allows For Highly Targeted Treatment
The FDA has approved the first radioimmunotherapy, a biotechnological
breakthrough that couples a radioactive isotope to a monoclonal
antibody that can target a specific type of malignant
cell. The new treatment, Zevalin, consists of the monoclonal
antibody ibritumomab tiuxetan linked to the radioisotope
yttrium-90. It is approved for treating low-grade, follicular,
or transformed B-cell non-Hodgkin’s lymphoma (NHL)
in patients who have relapsed or who haven’t responded
to standard chemotherapy or treatment with the monoclonal
antibody rituximab (Rituxan). The Zevalin regimen has
two stages: Patients first receive rituximab (which, in
effect, helps prepare the targeted sites) followed by
a test dose of Zevalin linked to a low-radiation isotope.
If the test dose shows the tumors are properly targeted,
the patient receives a second infusion of rituximab seven
to nine days later followed by Zevalin linked with the
radioisotope yttrium-90. In a study of NHL patients not
responding to chemotherapy, 74% responded to the Zevalin
regimen, with 15% achieving remission. In a study comparing
the Zevalin regimen to rituximab alone, the overall response
rates were 80% vs. 56%, respectively. Prolonged and severe
cytopenias occurred in the majority of patients receiving
yttrium-90 Zevalin. Life-threatening infection occurred
in 2%, and GI hemorrhage in 1%. Fatal infusion reactions
have occurred within 24 hours of rituximab infusions.
U.S. Food and Drug Administration.
“FDA
approves first radiopharmaceutical product to treat non-Hodgkin’s
lymphoma.” 2002. www.fda.gov/bbs/topics /answers/2002/ans01138.html
(26 Feb. 2002). Based on a news release by IDEC Pharmaceuticals
Corporation, February 19, 2002. “Zevalin therapeutic
regimen receives FDA marketing approval; first radioimmunotherapy
approved by FDA.” www.idec pharm.com/site/index.htm
(27 Feb. 2002).
[TOP]
Gleevec
Approved For Patients With GI Stromal Cancer
Imatinib mesylate (Gleevec), a drug introduced last May
for chronic myeloid leukemia, received accelerated FDA
approval for treating inoperable and metastatic gastrointestinal
stromal tumor (GIST). The cancer typically emerges within
the GI tract and metastasizes within the abdomen or pelvis.
Imatinib was studied in 147 patients with inoperable or
metastatic GIST. While no patient had complete remission,
38% had a partial response (tumor size reduced by 50%
or more). The duration of response is still under study.
The most common adverse events were edema, nausea, vomiting,
diarrhea, muscle cramps, liver toxicity, rash, and reduced
blood cell counts. Therapy was discontinued in six patients
because of adverse events. Seven patients required red
blood cell transfusions because of GI or intratumoral
bleeding.
U.S.
Food and Drug Administration. “FDA approves Gleevec
to treat gastrointestinal stromal cancer.” 2002.
www.fda.gov/bbs/topics/answers/2002 /ans01134.html (11
Feb. 2002).
[TOP]
Black
Box Warning Added To Antidepressant’s Labeling
Revised labeling and patient information have been issued
for the antidepressant nefazodone (Serzone) to warn of
rare cases of liver failure leading to transplant and/or
death. The rate is estimated, conservatively, to be three
to four times higher than the average rate of liver failure
in the general population. Liver injury from nefazodone
has been reported to occur within two to 24 weeks of starting
treatment. The “Black Box warning” now advises
providers not to start the drug in patients with active
liver disease or elevated baseline serum transaminases.
It also advises them to stop (and not restart) it in patients
who develop signs or symptoms suggesting liver failure,
such as increases in serum AST, or serum ALT levels three
or more times higher than the upper normal limit. Patients
should call their healthcare provider immediately if they
develop jaundice, unusually dark urine, anorexia, nausea,
abdominal pain, malaise, or other symptoms of liver problems.
Periodic liver function testing is recommended.
U.S.
Food and Drug Administration MedWatch. “Serzone (nefazodone
HCl).” 2002. www.fda.gov/medwatch/safety/2002/safety02.htm#serzon
(10 Jan. 2002).
[TOP]
New
Anemia Drug For Use In Chronic Renal Failure
Darbepoetin alfa (Aranesp) has been approved for the treatment
of anemia associated with chronic renal failure—whether
patients are on dialysis or not. The new drug has a half-life
that’s about three times longer than the existing
treatment, epoetin alfa (Epogen, Procrit). As a result,
darbepoetin should be given less frequently. Its recommended
starting dose is one injection (0.45 mcg/kg) per week,
but patients who’ve been receiving epoetin once a
week should be given darbepoetin once every two weeks.
Patients receiving either treatment need to be carefully
monitored because, in studies, very serious adverse events—including
cardiac arrest, neurologic events, and vascular thrombosis/ischemia/infarction—were
associated with increases in hemoglobin greater than approximately
1.0 gm/dL during any two-week period. The most common
adverse effects with darbepoetin are infection, hypertension,
hypotension, myalgia, headache, and diarrhea. Monitor
patients also for rare, but potentially serious allergic
reactions, including skin rash and urticaria. The drug
shouldn’t be used in patients with uncontrolled hypertension.
Based
on a news release by Amgen, September 18, 2001. “FDA
approves Amgen’s Aranesp for anemia associated with
chronic renal failure.” www.amgen.com/news/news01/pressRelease010918.html
(21 Sept. 2001).
[TOP]
A
Woman’s Pain, Not Dilation, Should Decide Epidural
Timing
The American College of Obstetricians and Gynecologists
and the American Society of Anesthesiologists jointly
issued a position statement reaffirming that, in the absence
of a contraindication, epidural analgesia should be given
during any stage of labor if a woman requests it. Some
hospitals delay an epidural until a women reaches 4 –
5 cm of dilation because studies indicate that giving
one early in labor increases the need for cesarean delivery.
The two organizations support delaying it “when feasible,”
but say a woman’s request for relief of severe labor
pain should be the deciding factor on when to give the
epidural.
American
College of Obstetricians and Gynecologists. “ACOG
supports epidural pain relief on demand.” 2002. www.acog.org/from_home/publications/press_releases/nr01-31-02-1.htm
(1 Feb. 2002).
[TOP]
Problem
Rx
Will This Arthritis Drug Interfere With Aspirin? A 57-year-old
patient had his first MI about one year ago. His cardiologist
prescribes 81 mg of aspirin once daily as prophylaxis
against another MI. The patient is already taking 400
mg tid of ibuprofen (Advil, Motrin) for his severe arthritis
pain, and the doctor says he should continue with it.
Is there a risk of interaction?
Yes.
In a recent study published in the New England Journal
of Medicine, ibuprofen was found to reduce the antiplatelet
activity by which aspirin protects against a second heart
attack. The patient should be switched to an arthritis
medication that will treat his severe pain without limiting
aspirin’s prophylactic efficacy. Acetaminophen, the
COX-2 inhibitor rofecoxib (Vioxx), and diclofenac (Voltaren)
were also used in the study and didn’t interfere
with aspirin. COX-2 inhibitors, which include celecoxib
(Celebrex), may not be a first choice for this patient,
however, since they are currently being studied for potential
cardiovascular effects.
(See
“Pain Clinic” in the July 2001 issue of RN.)
Source: Catella-Lawson, F., Reilly, M. P., et al. (2001).
Cyclooxygenase inhibitors and the antiplatelet effects
of aspirin. N Engl J Med, 345(25), 1809. THE AUTHOR LINDA
M. PORTERFIELD, RN, PhD, is a clinical pharmacologist
and director of cardiovascular research at Arrhythmia
Consultants in Memphis. She works with her husband, James
Porterfield, MD, FACC, who is a cardiologist and electrophysiologist.
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