An extended-release formulation of the centrally-acting muscle relaxant cyclobenzaprine (Amrix - Cephalon) has been approved by the FDA for treatment of muscle spasms. Immediate-release (IR) cyclobenzaprine (Flexeril, and others) has been available since 1977.

The FDA has approved fostamatinib disodium hexahydrate (Tavalisse – Rigel), the first spleen tyrosine kinase (SYK) inhibitor, for oral treatment of thrombocytopenia in adults with chronic immune thrombocytopenia (ITP) who have had an insufficient response to a previous treatment.

A once-daily oral formulation of mesalamine (Lialda - Shire) was recently approved by the FDA for induction of remission in patients with mild to moderate ulcerative colitis.

Vorinostat (Zolinza - Merck), an oral histone deacetylase (HDAC) inhibitor, has received accelerated approval from the FDA for treatment of skin manifestations of cutaneous T-cell lymphoma (CTCL) that is persistent, progressive or recurrent after two systemic therapies. The most common types of CTCL are mycosis fungoides and SΘzary syndrome, the leukemic form of mycosis fungoides.

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.

Gabapentin (Neurontin - Parke-Davis), a cyclohexane acetic acid derivative, has been approved by the US Food and Drug Administration for use in addition to other antiepileptic drugs in patients with partial (focal) seizures with or without secondary generalization. Since this diagnostic category includes the largest number of patients with intractable epilepsy, new drugs with antiepileptic activity are generally tried first for this indication.

The US Food and Drug Administration has approved the marketing of 5% doxepin hydrochloride cream (Zonalon - GenDerm) for treatment of pruritus due to eczematous dermatoses. Oral doxepin is used as a tricyclic antidepressant (Sinequan, and others).

Belzutifan (Welireg – Merck), a first-in-class hypoxia-inducible factor inhibitor, has been approved by the FDA for treatment of advanced renal cell carcinoma (RCC) in adults who received prior treatment with a programmed death receptor-1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitor and a vascular endothelial growth factor tyrosine kinase inhibitor (VEGF-TKI). Belzutifan was previously approved for use in patients with von Hippel-Lindau disease.

Some Medical Letter consultants have suggested that our recent article on dermal fillers (Med Lett Drugs Ther 2007; 49:39) should have included stronger warnings about the risk of fillers that are not biodegradable, such as Artefill. The polymethylmethacrylate (PMMA, the same material that makes up Plexiglas) beads in Artefill can over time, even with the best technique, cause foreignbody granulomas and hypertrophic scarring, which may require surgical removal. Granulomas and nodules have been especially frequent when Artefill was injected into the lips. Complications are less likely with...

In the CLINICAL STUDIES - Other Cancers paragraph (Med Lett Drugs Ther 2007; 49:35), the dosage in the first line should be 2.5 mg/kg, not 25 mg/kg.