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).

Tacrine hydrochloride (Cognex - Parke-Davis), an acridinamine derivative, will soon be available for treatment of cognitive deficits associated with Alzheimer's disease.

Venlafaxine hydrochloride (Effexor - Wyeth-Ayerst) was recently approved by the US Food and Drug Administration for treatment of depression. An aminomethyl-benzyl- cyclohexanol, it is chemically related to bupropion (Wellbutrin).

Tramadol hydrochloride (Ultram - Ortho-McNeil), a centrally-acting analgesic marketed in Germany since 1977, was recently approved by the US Food and Drug Administration for oral treatment of moderate to moderately severe pain. Despite some opioid activity, tramadol has not been scheduled as a controlled substance.

Lansoprazole (Prevacid -TAP), a proton pump inhibitor similar to omeprazole (Prilosec - Medical Letter, 32:19, 1990), has been approved by the US Food and Drug Administration for short-term treatment of active duodenal ulcer and erosive reflux esophagitis and for long-term treatment of chronic hypersecretory conditions, including the Zollinger-Ellison syndrome.

Nisoldipine (Sular -Zeneca), a dihydropyridine calcium-channel blocker structurally similar to nifedipine, has been approved for marketing by the US Food and Drug Administration. It is available in an oral extended-release formulation for treatment of hypertension.

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.

Topiramate (Topamax - Ortho-McNeil) has been approved by the US Food and Drug Administration (FDA) for oral use as an adjunct to other drugs in adult patients with partial seizures. Since this diagnostic category includes the largest number of patients with refractory epilepsy, new drugs with antiepileptic activity are usually tried first for this indication. Topiramate (toe pyre' a mate) is a structurally unique agent chemically related to the D-enantiomer of fructose.

Topical tretinoin (all-trans-retinoic acid) has been used for years to treat skin damaged by chronic exposure to the sun (Medical Letter, 34:28, 1992). First approved by the FDA only for treatment of acne in concentrations ranging from 0.025% to 0.1% (Retin-A, and others), it has now been approved as an 0.05% formulation in an emollient cream base (Renova) for topical treatment of photodamaged skin. In recent years, alpha-hydroxy acids incorporated in some cosmetics have also been promoted as effective in improving the appearance of aging skin.

Sildenafil citrate (Viagra - Pfizer) is the first oral drug approved by the FDA for treatment of erectile dysfunction. Alprostadil is also marketed for this indication but must be injected into the corpus cavemosum (Caverject) or pushed into the urethra (MUSE).