Market watch

New Generics

• Granisetron tablets (generic Kytril)11
• Tenofovir dipivoxil (generic Viread), tentatively approved12
• Topiramate tablets (generic Topamax)13

New Drugs, Indications & Dosage Forms

• Budesonide/formoterol fumarate dihydrate 160/4.5 mcg (Symbicort), previously approved by the FDA to treat asthma, has been FDA-approved to treat chronic obstructive pulmonary diseases, including chronic bronchitis and emphysema. It is dosed twice daily.14
• Glatiramer acetate (Copaxone), already FDA-approved for treating relapsing-remitting multiple sclerosis (MS), has been approved by the FDA as a preventive treatment in patients that have had a first episode of MS and have magnetic resonance imaging (MRI) results consistent with MS, also known as having a clinically isolated syndrome (CIS) suggestive of MS.15
• Tigecycline (Tygacil) has been FDA-approved to treat adults with community-acquired bacterial pneumonia by susceptible strains of indicated pathogens.16 An initial dose of 100 mg is recommended, followed by 50 mg every 12 hours intravenously over approximately 30 to 60 minutes for seven to 14 days.17

New Warnings

• Wearing medicated transdermal patches while undergoing MRI scans can cause skin burns on the direct patch area.18 Many transdermal patches contain metallic backing or other layers, including aluminum, that can overheat during an MRI. Patches are used to treat many conditions, including antiemesis, attention deficit hyperactivity disorder, depression, and pain, and are also used in hormone replacement and smoking cessation. The FDA is reviewing the composition and labeling of all medicated patches to ensure those that contain metal provide a patient a warning of potential burns. Until then, healthcare providers are being told to warn patients to remove and dispose of them prior to an MRI. The patch can be replaced after the scan. Patients should tell the MRI facility that they are using a patch when they call to schedule their appointment.19
• Metoclopramide has been used for many years in the management of gastrointestinal disorders. Healthcare providers also have known, and it is listed in the product label, that this agent can cause tardive dyskinesia. However, the FDA now feels that it is necessary to warn healthcare providers and patients of this risk, which is mostly associated with long-term, high-dose use. Patients with the highest risk include the elderly (especially older women), and those who have been on the drug for a long time. In February, the FDA instituted a boxed warning and risk mitigation strategy for metoclopramide-containing drugs. This ensures that patients are provided with a medication guide that warns them of the risk.20
• Through a clinical data review, the FDA has determined that zonisamide (Zonegran), an anti-epileptic drug (AED) utilized to treat adults with partial epilepsy, can sometimes cause metabolic acidosis in some patients. Therefore, the product labeling for zonisamide has been updated. Healthcare professionals treating patients with zonisamide should measure serum bicarbonate at baseline before starting treatment and periodically throughout treatment, even if the patient is asymptomatic. Symptoms include fatigue, anorexia, hyperventilation, stupor, and cardiac arrhythmia. Predisposed individuals include those with renal impairment, diarrhea, those on a ketogenic diet, surgery, and severe respiratory disorders. If metabolic acidosis develops and persists, consider reducing the dose or discontinuing the treatment. The patient’s antiepileptic treatment should be modified as needed. If the decision is made to continue metabolic acidosis patients on zonisamide, then alkali treatment should be considered. More information and management tips can be found at www.fda.gov.21