NeutroSpec Withdrawn from Market

In the “FDA is getting serious, finally” category (via Medscape):

Dec. 19, 2005 “The US Food and Drug Administration (FDA), Mallinckrodt, and Palatin Technologies, Inc, have notified healthcare professionals regarding the immediate suspension of technetium [99m Tc] fanolesomab (NeutroSpec) from the market pending further investigation into reports of cardiopulmonary reactions associated with its use.

The action was based on the serious and potentially fatal nature of these adverse events and the availability of safer methods for diagnosing appendicitis, according to an alert sent today from MedWatch, the FDA’s safety information and adverse event reporting program.

There is no evidence of long-term risk among those who have safely received the product, according to the FDA.

The FDA has received postmarketing reports of 2 deaths and 15 life-threatening adverse events after administration of technetium [99m Tc] fanolesomab. Onset of these events occurred within minutes of injection and included cardiac arrest, hypoxia, dyspnea and hypotension requiring resuscitation with fluids, vasopressors, and oxygen.

A review of all postmarketing reports has yielded an additional 46 cases of similar but less severe adverse reactions, all occurring within minutes of technetium [99m Tc] fanolesomab administration. According to the FDA, the consistent characteristics and rapid onset of these events suggest that a causal role for the antibody component of the product is likely.

Technetium fanolesomab is a radiolabeled murine IgM monoclonal antibody indicated for use in the scintigraphic imaging of patients aged 5 years and older with equivocal signs and symptoms of appendicitis.

NeutroSpec has been taking out full-page ads in the EM trade journals touting its intended use in the diagnosis of ‘equivocal’ appendicitis. To my knowledge nobody at our joint ever used it. (And it’s too bad it’s gone, I was hoping it’d be useful in the pregnant RLQ-pain patient in which a sono didn’t help).

And, on to the rant: 10 years ago there was an ‘acceptable rate’ of about 10% for the removal of normal appendixes from patients with right lower quadrant abdominal pain. Since then there seems to be a major push to never take out an appendix without a CT or a sono confirming the appendix is the answer. This doesn’t sound like medical progress to me, it sounds a lot like CYA testing.

(We have one crusty surgeon who used to go ballistic when called that we have a positive appy on CT: “So, you had a patient with RLQ abdominal pain, rebound and guarding, and you got a CT instead of just calling me?”). He tries to assure us that none of the surgeons want a CT for appy, and we tell him, politely, that our experience with that same telephone call doesn’t bear out his assertion. (I want the crusty guy to just take mine out, thanks).

Yes, minimizing trips to the OR is arguably a good thing, and I’m not advocating needless surgery, but this is one example of the increasing applications of technology in medicine, whether it’s really needed or not.

Oh, and if you google for NeutroSpec, there’s already plaintiff atty. ads over on the right. And they have the gall to wonder why they aren’t well-regarded.


  1. Given your description of the surgeons at your hospital, color me “crusty.” Given my feelings about CT diagnosis of acute appendicitis, I’m kind of glad NeutroSpec won’t be around to further cloud the diagnostic picture any longer!

  2. Thanks for this info. I work part time in nuc med administering Persantine and supervising ETT Myoviews. Sometimes I get requested to do other studies when the nuc attending is not available and have been reluctant to do so, and now will be more so. When I first started doing these studies, the nuc rad attending and the nuc techs told me that the Myoview had no side effects. I found that a bit unbelievable, so did some reading and found that the Myoview does in fact have potential side effects. Think perhaps Mallinckrodt did the “education” of our nuc med staff!!

  3. Wow. I admitted a patient last night who had a history of “allergy” to technetium; I had never heard of this before. Good to know!

  4. My wife, a fellow emergency physician here at Landstuhl Regional Medical Center (Germany), had a 30yo male with classic signs for appendicitis (i.e. RLQ pain, RLQ ttp, rebound, guarding) a few nights ago. After completing her Hx and PE she called the SOD (surgeon of the day) for a consult stating that she believed her patient had an acute appendicitis that required surgical intervention. The surgeon, of course, asked her what the CBC and UA results were… She stated that they were still pending.

    The SOD went off on her questioning her reasoning for a surgical consult without the benefit of laboratory results… Taking the high road she calmly stated that the labs were pending and would be resulted shortly after his arrival to the ED. Upon his arrival he berated her in front of the entire ED staff for a premature consult. Again, taking the high road, she thanked him for arriving in the ED so quickly and directed him to the patient’s bedside. Moments after examining the patient he filled out a buck slip and took the patient to the OR for his appendectomy — the labs were still pending as he wheeled the patient to the OR…

    During his tirade, the SOD told my wife that he would be interested to hear what her colleagues’ positions are on calling for a surgical consult prior to labs being resulted — keep in mind that this patient was a “classic” presentation of acute appendicitis. My response was as follows (not all references used in this informal e-mail are listed — it was never intended for publication so please forgive any plagiarism of Tintinalli):

    Per our discussion…

    I believe patients with abdominal pain can be broken down into four groups:

    1. Patients who demonstrate classic presentation for acute appendicitis

    2. Patients with signs and symptoms that are suspicious but not diagnostic for appendicitis

    3. Patients with abdominal pain in whom appendicitis is considered to be a remote diagnostic possibility

    4. All high-risk special populations presenting with abdominal pain (i.e. elderly, pediatric, pregnant, immunocompromised)

    When evaluating a patient in group one I believe immediate surgical consultation is appropriate… While I would draw the usual labs (i.e. CBC, UA), I would NOT wait for their results before consulting surgery. After all, surgery is going to see this patient whether their WBC count is 8 or 80. Why delay surgical evaluation when the CBC and UA results will not change your decision to have this patient evaluated by a surgeon? The patient you described to me clearly fell into group one. I believe the surgeon would agree seeing as how he took the patient straight to the OR and removed his appendix. The finding of a normal appendix during surgery, while indicative of a misdiagnosis, should NOT be considered an error in the patient’s care. After all, a certain percentage of normal appendices should be removed by every general surgeon during the routine performance of their duties – cast a broad net and all… And while the historical accepted incidence of removing a normal appendix 20% of the time is no longer the gold standard due to the advances made in CT and US (Townsend: Sabiston Textbook of Surgery, 17th ed., Copyright © 2004 Saunders, An Imprint of Elsevier. P 1387), the occasional removal of a normal appendix when dealing with patients in group one is to be expected.

    As for the CBC – “The WBC is of limited value. The sensitivity of an elevated WBC above 10,000/uL in acute appendicitis is 70 to 90 percent, but the specificity is very low. More important, the positive and negative predictive values of an elevated WBC in acute appendicitis are 92 and 50 percent, respectively (Vermeulen B, Morabia A, Unger PF: Influence of white cell count on surgical decision making in patients with abdominal pain in the right lower quadrant. Eur J Surg 161:483, 1995. Hoffman J, Rausmussen O: Aids in the diagnosis of acute appendicitis. Br J Surg 76:774, 1989. Marchand A, Van Lente F, Galen RS: The assessment of laboratory tests in the diagnosis of acute appendicitis. Am J Clin Pathol 80:369, 1983.).”

    As for the UA – “Abnormal urinalysis results, excluding proteinuria, are found in 19 to 40 percent of patients with acute appendicitis. Abnormalities include pyuria, hematuria, and bacteriuria, possibly related to the extension of appendiceal inflammation to the ureter (Kretchmar LH, McDonald DF: The urine sediment in acute appendicitis. Arch Surg 87:209, 1963. Puskar D, Bedalov G, Fridrih S, et al: Urinalysis, ultrasound analysis, and renal dynamic scintigraphy in acute appendicitis. Urology 45:108, 1995.).”

    In conclusion, I agree with the immediate surgical consultation when caring for a patient that falls into group one. That is how I was trained. That is how I currently practice. That is how I will continue to practice. If the surgeon chooses to delay their evaluation until the labs are resulted then I must concede that making that decision falls within the scope of their practice. And they, of course, will then be held responsible should their decision to delay evaluation results in a poor outcome for the patient – albeit unlikely… Bottom line, however, is that an immediate surgical consult is clearly indicated in group one patients. The decision to wait for lab results and/or imaging and the ultimate decision of cut versus do not cut falls within the bailiwick of the surgeon being consulted on the case. I would have called before the labs were resulted…


    As you may have deduced — the patient did NOT have an acute appendicitis. I think he turned out to have a kidney stone!!!

    I would be interested to hear the perspectives of other EP’s out there regarding when to call for a surgical consult on patients that fit into group one (listed above)…

    In conclusion, thanks for I am a regular visitor to the site.



  1. Appendicitis and The CT scanner

    A commenter to this post by the Grunt Doc has resurrected the debate over the appropriateness of CT scanning to look for appendicitis. I will repost the well-written comment:

  2. medmusings says:

    links for 2005-12-24

    GruntDoc gets CT before calling on-call surgeon for eval of appendicitis. I often do as well, but agree with the commenter that in obvious cases, you don’t need labs or CT, just bring ’em to the OR! (tags: appendicitis) The Corpus Callosum: Modafinil,…