Conivaptan hydrochloride (Vaprisol - Astellas), a vasopressin antagonist, has been approved by the FDA for short-term intravenous (IV) treatment of euvolemic hyponatremia in hospitalized patients. Euvolemic hyponatremia is most often caused by the syndrome of inappropriate ADH secretion (SIADH), or by hypothyroidism or adrenal insufficiency. The drug has not been approved for treatment of hypervolemic hyponatremia, which is associated with congestive heart failure (CHF), cirrhosis and renal disease. It should not be used in hypovolemic hyponatremia, such as occurs when fluid losses are...

The FDA has approved two new inhalers for long-term maintenance treatment of chronic obstructive pulmonary disease (COPD). Seebri Neohaler (Novartis) contains the long-acting anticholinergic glycopyrrolate. Utibron Neohaler (Novartis) contains both glycopyrrolate and the long-acting beta2-adrenergic agonist (LABA) indacaterol. Glycopyrrolate/indacaterol is the third fixed-dose combination of a long-acting anticholinergic and a LABA to become available in the US; umeclidinium/vilanterol (Anoro Ellipta) and tiotropium/olodaterol (Stiolto Respimat) were approved...

The FDA has issued new warnings about the use of the opioid analgesics codeine and tramadol in children, particularly those <12 years old, and in breastfeeding women due to concerns about the risk of respiratory depression and death. The FDA previously issued warnings about these drugs in 2013 and 2015.

Pharmacologic management of opioid withdrawal symptoms can reduce the intensity of drug craving and improve treatment retention in patients with opioid use disorder who will receive maintenance treatment. Withdrawal management without subsequent maintenance treatment is associated with high rates of relapse, overdose death, and HIV and/or hepatitis C virus infection. Several guidelines on management of opioid withdrawal are available. Maintenance treatment of opioid use disorder was reviewed in a previous issue.

Summer heat waves cause thousands of cases of heat-related illness in the USA each year and hundreds of heat-related deaths, especially among the elderly. A few principles may be helpful in preventing and treating heat injury.

Loratadine (Claritin - Schering), a new H 1 -receptor antagonist, has been approved by the U.S. Food and Drug Administration for treatment of seasonal allergic rhinitis in patients more than 12 years old. It will compete with older, relatively sedating drugs such as chlorpheniramine (Chlor-Trimeton, and others) and clemastine (Tavist - Medical Letter, 35:9, 1993) and with newer relatively non-sedating agents such as terfenadine (Seldane) and astemizole (Hismanal).

Isosorbide mononitrate, the major active metabolite of isosorbide dinitrate, was first approved in the USA for oral use in patients with chronic stable angina in 1992 (Medical Letter, 34:61, 1992). Now an extended-release formulation of isosorbide mononitrate (Imdur -Key) has been approved by the US Food and Drug Administration.

Several readers have asked the Medical Letter to evaluate the effectiveness and safety of exogenous melatonin for treatment of insomnia and jet lag. Melatonin has not been approved by the US Food and Drug Administration (FDA), but is available in health food stores and apparently is being used as self-medication to treat a wide variety of disorders.

An intravenous formulation of amiodarone (Cordarone IV -Wyeth-Ayerst) has been approved by the US Food and Drug Administration (FDA) for treatment and prophylaxis of recurrent ventricular fibrillation (VF) or hemodynamically unstable ventricular tachycardia (VT) in patients refractory to other therapy.

Zileuton (zye loo' ton; Zyflo - Abbott), an inhibitor of leukotriene synthesis, has been approved by the US Food and Drug Administration (FDA) for prophylaxis and maintenance treatment of chronic asthma in adults and children more than 12 years old. A related drug—zafirlukast (Accolate), a leukotriene receptor antagonist—was recently reviewed in the Medical Letter (vol. 38, page 111, December 20, 1996). Neither of these drugs is recommended for treatment of acute asthma.