Adenosine (Adenocard - Fujisawa), an endogenous purine nucleoside, was recently approved by the US Food and Drug Administration for intravenous treatment of paroxysmal supraventricular tachycardia, including Wolff-Parkinson-White (WPW) syndrome. Adenosine is not approved for and has not been effective in treating atrial flutter, atrial fibrillation, or ventricular tachycardias.

Pegademase (Adagen - Enzon), bovine adenosine deaminase (ADA) conjugated with polyethylene glycol (PEG), was recently approved by the US Food and Drug Administration as an 'orphan drug' for treatment of severe combined immunodeficiency disease (SCID). SCID due to inherited deficiency of ADA occurs in less than one per million births; until recently, without extraordinary isolation measures, it was usually fatal before the age of two.

Isradipine (DynaCirc - Sandoz), a dihydropyridine calcium-channel blocker chemically related to nicardipine (Cardene) and nifedipine (Procardia, and others), was recently approved by the US Food and Drug Administration for oral treatment of hypertension.

(Ceredase - Genzyme) a modified form of the glycoprotein enzyme glucocerebrosidase prepared from human placenta, was recently approved by the US Food and Drug Administration as an 'orphan drug' for treatment of patients with the non-neurologic form of Gaucher's disease (Type 1).

Pilocarpine hydrochloride (Salagen- MGI Pharma), a cholinergic agonist long available in an ophthalmic formulation for treatment of glaucoma (Pilocar, and others), was recently approved by the US Food and Drug Administration (FDA) for oral treatment of radiation-induced xerostomia (dry mouth) in patients with head and neck cancer.

Gemcitabine (jem site a been) hydrochloride (Gemzar - Lilly), a nucleoside analog, has been approved by the US Food and Drug Administration for intravenous (IV) use in the first-line treatment of locally advanced or metastatic adenocarcinoma of the pancreas and in patients with pancreatic cancer previously treated with fluorouracil (Adrucil, and others). No previously available drug has had more than minor activity in treating this disease.

Irinotecan hydrochloride (Camptosar - Pharmacia & Upjohn; formerly CPT-11) has been approved by the US Food and Drug Administration for treatment of metastatic colorectal cancer refractory to other drugs including fluorouracil (5-FU; Adrucil and others).

The FDA has approved the marketing of Natazia (Bayer), a 4-phase oral contraceptive containing the estrogen estradiol valerate and the progestin dienogest, both used for the first time in the US for this indication.

In 2011, the FDA asked the manufacturers of the selective serotonin reuptake inhibitor (SSRI) citalopram (Celexa, and generics) to lower the maximum daily dosage of the drug because of a dose-related increase in the QT interval. Since then, some of our readers have asked whether escitalopram (Lexapro, and generics), the active enantiomer of citalopram, could have the same effect.

A reader expressed concern that a statement in our article Naloxone (Narcan) Nasal Spray for Opioid Overdose (Med Lett Drugs Ther 2016; 58:1) might be misleading. We stated that heroin has a half-life of 2-6 minutes, which is correct, but heroin is a prodrug that is rapidly metabolized to 6-acetylmorphine and morphine. The risk of respiratory depression is related to those active metabolites, and it may persist well beyond the clearance of heroin from the blood.