Duloxetine hydrochloride (Cymbalta - Lilly), a selective serotonin and norepinephrine reuptake inhibitor (SNRI) available for treatment of depression, has also been approved by the FDA for treatment of neuropathic pain associated with diabetic peripheral neuropathy (DPN). Duloxetine is one of two drugs approved specifically for management of neuropathic pain due to diabetes; the other, pregabalin (Lyrica - Pfizer), will be marketed soon and will be reviewed in the next issue of The Medical Letter.

Bendamustine HCl (Treanda - Cephalon), an unusual DNA-alkylating agent that has been used in Europe for many years to treat lymphoma, has now been approved by the FDA for treatment of chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL).

The FDA has approved Dovato (ViiV), a fixed-dose combination of the integrase strand transfer inhibitor (INSTI) dolutegravir (Tivicay) and the nucleoside reverse transcriptase inhibitor (NRTI) lamivudine (Epivir, and generics), as a once-daily complete regimen for treatment of adults with HIV-1 infection who are antiretroviral-treatment naive and have no known substitutions associated with resistance to either drug. Dolutegravir/lamivudine is the first complete regimen to be approved by the FDA for initial treatment of HIV-1 infection that contains 2 rather than 3 antiretroviral...

The FDA has approved cenobamate (Xcopri – SK Life Science) for oral treatment of partial-onset (focal) seizures in adults.

The FDA has approved Apretude (ViiV Healthcare), an IM extended-release (ER) formulation of the integrase strand transfer inhibitor (INSTI) cabotegravir, for use every 2 months to prevent sexually acquired HIV-1 infection in at-risk adolescents and adults. Apretude is the first ER formulation to be FDA-approved for pre-exposure prophylaxis (PrEP) of HIV-1 infection.

Gabapentin (Neurontin - Pfizer), which has been available in the US since 1994, is approved by the FDA only for treatment of partial epilepsy and postherpetic neuralgia, but is widely used off-label for a number of other indications, especially neuropathic pain syndromes. According to one report, among Medicaid recipients in Florida receiving gabapentin, 71% of prescriptions were for chronic pain and 8% for seizures and neuralgia ("The Pink Sheet" February 2, 2004; 66:30).

Erlotinib (Tarceva) is the second oral epidermal growth factor receptor (EGFR) inhibitor to become available in the US for treatment of advanced refractory NSCLC. In clinical trials, erlotinib produced a response rate of only 8.9%, but increased median survival from 4.7 to 6.7 months. Patients who had never smoked and those with EGFR-positive tumors survived longer. Erlotinib is generally well tolerated; diarrhea and rash are the most common adverse effects.

The FDA recently approved the monoamine oxidase inhibitor (MAOI) selegiline in a transdermal (patch) formulation (Emsam - Bristol-Myers Squibb/Somerset) for treatment of major depressive disorder. Selegiline is also available in an oral formulation (Eldepryl, and others) for treatment of Parkinson's disease.

Warfarin sodium (Coumadin, and others) and other coumarin anticoagulants prevent thrombosis, but patient response is highly variable and overanticoagulation can lead to hemorrhage. Genotyping patients for single nucleotide polymorphisms (SNPs) that affect coumarin metabolism and sensitivity may help clinicians estimate the therapeutic warfarin dose. The FDA has added a note to warfarin labeling recommending lowrange doses for patients with such genetic variations. Commercial tests for these variants are now available and cost about $500 per test.

A recent letter to the editor of the Annals of Internal Medicine documented a single case of myopathy apparently due to an interaction between simvastatin (Zocor, and others) and green tea. Since it became available generically, simvastatin has surpassed atorvastatin (Lipitor) as the best selling statin. As such, it is probably the most common cause of statin-induced myopathy, which is often a result of drug interactions.