Lisdexamfetamine dimesylate (Vyvanse - Shire), a prodrug in which d-amphetamine is covalently bonded to L-lysine, has been approved by the FDA for treatment of attention-deficit/hyperactivity disorder (ADHD) in children 6-12 years old. It was designed to have less potential than amphetamine itself for abuse, diversion or overdose toxicity. Like methylphenidate and amphetamines, lisdexamfetamine is a Schedule II controlled substance.

The FDA has approved a transmucosal tablet formulation of fentanyl citrate (Fentora - Cephalon) for management of breakthrough pain in opioid-tolerant patients with cancer. An oral transmucosal fentanyl lozenge on a stick (Actiq, and others) is also available for this indication, and is widely used off-label for chronic, non-cancer pain as well.

Ambrisentan (Letairis - Gilead), a selective endothelin type A (ET_A) receptor antagonist, has been approved by the FDA for treatment of symptomatic patients (WHO class II or III) with pulmonary arterial hypertension (PAH).

Formoterol fumarate (Perforomist - Dey), a long-acting beta₂-agonist, was recently approved by the FDA as an inhalation solution for nebulization for maintenance treatment of bronchoconstriction associated with chronic obstructive pulmonary disease (COPD). Arformoterol (Brovana), the (R, R)-enantiomer of formoterol, was approved earlier this year for the same indication.

Medical Letter consultants have brought to our attention some confusion that has accompanied the release of Adacel, a combination of tetanus toxoid, diphtheria toxoid and acellular pertussis antigens (Tdap) recently approved for use as a booster in adolescents and adults 11-64 years old (Med Lett Drugs Ther 2006; 48:5). Another Tdap vaccine, Boostrix, is approved for use in adolescents 10-18 years old. Some adults have inadvertently been immunized with Daptacel or Infanrix (DTaP), which are intended for active immunization of infants and children 6 weeks to 6 years old. Such mix-ups were...

In the recent Medical Letter article on the treatment of Clostridium difficile–associated disease (CDAD) we wrote: “Healthcare workers caring for patients with C. difficile infection should follow contact isolation precautions, especially use of gloves and hand washing with soap and water after glove removal. Alcohol-based products such as hand sanitizers will not eradicate C. difficile spores.”1 One reader pointed out that alcoholbased products do eradicate some C. difficile spores and have been invaluable against other pathogens.In an unpublished study available as an abstract, both...

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,...

A reader expressed disappointment that our recent listing of “Some Warfarin Drug Interactions”1 did not include acetaminophen. Perhaps it should have. Acetaminophen can increase the anticoagulant effect of warfarin, particularly with continued use, but it does so inconsistently. The mechanism of this interaction has not been established, but may be related to an acetaminophen metabolite inhibiting vitamin K-epoxide reductase, the target for warfarin’s anticoagulant effect.2Patient susceptibility varies, possibly on a genetic basis; occasional use of acetaminophen generally has little or...

The nicotine receptor partial agonist varenicline (Chantix - Pfizer) appears to be the most effective drug available to treat tobacco dependence, but the FDA has added a warning to the package insert about neuropsychiatric symptoms and exacerbations of preexisting psychiatric illness associated with its use. Agitation, hostility, depressed mood, suicidal ideation and suicidal behavior have been reported as postmarketing adverse events in patients who took varenicline and stopped smoking and in those who took the drug and continued to smoke.

The American Heart Association (AHA) recently published a statement saying that it would be reasonable to obtain an electrocardiogram (ECG) in children being evaluated for stimulant drug therapy for attention deficit hyperactivity disorder (ADHD). A subsequent news release in conjunction with the American Academy of Pediatrics provided a clarification, saying that it would be reasonable to consider obtaining an ECG in such children.