Many prescriptions for eye drops call for instillation of 1-2 drops. But Medical Letter consultants in ophthalmology seem to agree that all eye drops should generally be given in doses of only one drop. The volume of a single drop can vary with the viscosity of the solution, the design of the dropper, and patient technique. The average volume of a drop is 35-50 microliters, but can be as high as 75 microliters. An eye brimming with fluid holds 30 microliters at best, so even one drop is often an overdose. A second either washes out the first or increases the possibility of systemic toxicity,...

The FDA has approved deutetrabenazine (Austedo – Teva), a vesicular monoamine transporter 2 (VMAT2) inhibitor, for treatment of chorea associated with Huntington's disease and, more recently, for treatment of tardive dyskinesia in adults. It is the second VMAT2 inhibitor to be approved for each of these indications; tetrabenazine (Xenazine, and generics) was approved earlier for Huntington's chorea and valbenazine (Ingrezza) was recently approved for treatment of adults with tardive dyskinesia.

The FDA has approved baloxavir marboxil (Xofluza – Shionogi/Genentech), the first polymerase acidic (PA) endonuclease inhibitor, for single-dose, oral treatment of acute uncomplicated influenza in patients ≥12 years old. Baloxavir is the first drug with a new mechanism of action to be approved for treatment of influenza in almost 20 years.

Two recombinant vaccines, Arexvy (GSK) and Abrysvo (Pfizer), have been approved by the FDA for prevention of lower respiratory tract disease (LRTD) caused by respiratory syncytial virus (RSV) in adults ≥60 years old. They are the first RSV vaccines to be approved in the US. Abrysvo is also approved for use in pregnant women at 32-36 weeks' gestation to prevent LRTD caused by RSV in their infants from birth through 6 months of age.

Anistreplase (Eminase - SmithKline Beecham, Upjohn), a plasminogen activator also known as APSAC, was recently approved by the US Food and Drug Administration (FDA) for intravenous (IV) thrombolytic treatment of coronary thrombosis. Three other thrombolytic agents - intracoronary urokinase (Abbokinase) and intracoronary or intravenous streptokinase (Streptase; Kabikinase) and alteplase (TPA; Activase)- were previously approved for coronary thrombolysis (Medical Letter, 29:107, 1987).

Famciclovir (Famvir - SmithKline Beecham) is now available in the USA for oral treatment of acute uncomplicated herpes zoster (shingles). The manufacturer claims that use of the drug reduces the duration of postherpetic neuralgia. Famciclovir is similar to acyclovir (Zovirax - Burroughs Wellcome), which has been the drug of choice for treatment of varicella-zoster and herpes simplex virus infections (Medical Letter, 36:27, 1994).

Bexarotene, a retinoid analog, has been approved by the US Food and Drug Administration for oral treatment of dermatologic manifestations of refractory cutaneous T-cell lymphoma.

Tazarotene (taz ar' oh teen, Tazorac - Allergan), an acetylinic retinoid marketed for treatment of psoriasis (Medical Letter 1997; 39:105), is also available as a 0.1% gel and cream for treatment of acne.

With the removal of Vioxx from the market and concerns about cardiovascular toxicity with other selective COX-2 inhibitors, patients are looking for safe alternatives, and manufacturers of other drugs are looking for additional market share. The COX-2 inhibitors first became popular because they have less upper GI toxicity than older less selective NSAIDs, at least in the short term, in patients not taking aspirin.

A large mumps outbreak that began in Iowa in December 2005 has spread. About 40% of the cases have been in people 18-25 years old, many of whom are college students and had been vaccinated against the disease.