Methylphenidate is now available in a new extended-release formulation (Metadate CD - Celltech) for treatment of attention deficit/hyperactivity disorder (ADHD). The new product, which is a Schedule II controlled substance, is being advertised directly to consumers.

Short-acting methylphenidate (MPH) is effective for treatment of attention-deficit/hyperactivity disorder (ADHD), but its 3-5 hour duration of action usually requires mid-day dosing in school, which children may find disruptive or stigmatizing.

Atomoxetine (Strattera - Lilly) is the first non-stimulant drug to be approved by the FDA for treatment of attention deficit hyperactivity disorder (ADHD). Unlike other drugs approved for use in ADHD, it is not a controlled substance and is approved for use in adults as well as children. Older non-stimulant drugs that have been used to treat ADHD, although not FDA-approved, include the alpha₂-agonist clonidine (Catapres, and others) and the tricyclic antidepressant desipramine (Norpramin, and others) (Medical Letter 1996; 38:109).

The FDA has approved Aptensio XR (Rhodes), an extended-release formulation of methylphenidate hydrochloride, for treatment of attention-deficit/hyperactivity disorder (ADHD). The Aptensio XR capsules contain multilayer beads designed to provide both a rapid onset and a long duration of action. This formulation of methylphenidate has been available in Canada as Biphentin since 2006.

Dexmethylphenidate (Focalin - Novartis), a new formulation of methylphenidate (Ritalin, and others) is now available for treatment of attention deficit/hyperactivity disorder (ADHD). Dexmethylphenidate is the d-threo-enantiomer of racemic methylphenidate. "Now the right half may be all your patients need," said a recent ad. Focalin is the third new methylphenidate formulation marketed in the last two years.

The FDA has approved a once-daily, extended-release chewable tablet formulation of methylphenidate (QuilliChew ER – Pfizer) for treatment of attention-deficit/hyperactivity disorder (ADHD). It is the first long-acting chewable formulation of the drug to be marketed in the US. Immediate-release chewable methylphenidate tablets (Methylin, and generics) have been available since 2003.

The FDA has approved a once-daily, extended-release oral suspension of methylphenidate (Quillivant XR – Pfizer) for treatment of attention-deficit/hyperactivity disorder (ADHD). It is the first liquid formulation of the drug to be marketed for once-daily use. A short-acting oral solution (Methylin, and generics) has been available since 2003.

A transdermal patch formulation of methylphenidate (Daytrana - Noven/Shire) has been approved by the FDA for treatment of attention-deficit/hyperactivity disorder (ADHD) in patients ≥ 6 years old. Like other methylphenidate products, the patch is a schedule II controlled substance. According to the manufacturer, it will be available in pharmacies by the end of June.

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,...