Bexxar, a combination of the monoclonal antibody tositumomab and radiolabeled Iodine-131 tositumomab (Corixa Corp/GlaxoSmithKline) has been approved by the FDA for a single treatment of relapsed follicular non-Hodgkin's lymphoma (NHL) in patients who are refractory to rituximab (Rituxan - Medical Letter 1998; 40:65). It is the second radioimmunoconjugate to be approved for refractory NHL; yttrium-90 linked to ibritumomab tiuxetan (Zevalin) was approved in 2002. Tositumomab, like ibritumomab, is a monoclonal antibody of mouse origin that binds to the CD20 antigen present on the surface of >90%...

Even though it is unlikely that people living in the US will be at risk of significant radiation exposure from the nuclear accident in Japan, some readers have suggested a review of the use of potassium iodide (KI) in such circumstances. Potassium iodide taken orally before or at the time of exposure can limit or prevent uptake of radioactive iodine by the thyroid gland.

The FDA has approved the use of the oral multikinase inhibitor sorafenib (Nexavar – Bayer) for treatment of locally recurrent or metastatic, progressive, differentiated thyroid cancer (papillary or follicular) refractory to radioactive iodine treatment. Sorafenib was approved earlier for treatment of advanced renal cell and unresectable hepatocellular cancer.

Primary hypothyroidism is usually the result of Hashimoto's thyroiditis, thyroidectomy for hyperthyroidism, goiter or cancer, or radioactive iodine therapy for hyperthyroidism.

The FDA has approved the oral multikinase inhibitor lenvatinib (Lenvima – Eisai) for treatment of locally recurrent or metastatic, progressive, differentiated thyroid cancer (papillary or follicular) refractory to radioactive iodine treatment.

The US Food and Drug Administration recently approved the marketing of ioversol (Optiray - Mallinckrodt), a new iodinated, low-osmolality, non-ionic X-ray contrast agent. Low-osmolality contrast agents are much more expensive, but they provide as good diagnostic quality as older, high-osmolality contrast media and are claimed to be both better tolerated and safer (Medical Letter, 29:43, 1987).

The FDA has required labeling changes that replace serum creatinine (SCr) with estimated glomerular filtration rate (eGFR) as the parameter used to determine the appropriateness of treatment with the biguanide metformin (Glucophage, and others) in patients with renal impairment. These changes will allow more patients with mild to moderate renal impairment to receive metformin, which is generally the first drug prescribed for treatment of type 2 diabetes.Metformin was previously contraindicated in women with a SCr level ≥1.4 mg/dL and in men with a SCr level ≥1.5 mg/dL, but use of SCr as a...

Results from a double-blind trial suggest that off-label use of the oral antihyperglycemic drug metformin in patients with COVID-19 may decrease the risk of post-acute sequelae of SARS-CoV-2 infection ("long COVID").

Gadolinium-based contrast agents, which are used mainly for magnetic resonance imaging and angiography, were first introduced partly because of the discovery in the 1990’s that iodine-based contrast agents could cause nephrotoxicity and acute renal failure. Some recent reports have suggested, however, that gadolinium-based agents may also be nephrotoxic.1 One patient who developed acute renal failure after use of gadolinium-based contrast had a renal biopsy that showed acute tubular injury.2Moreover, after exposure to gadolinium-based contrast, some patients with severe renal insufficiency,...

Antimicrobial prophylaxis can decrease the incidence of postoperative surgical site infection after some procedures. Since the last Medical Letter article on this subject, consensus guidelines have been published. Recommendations for prophylaxis in specific surgical procedures are listed in Table 1.