Dichlorphenamide (Keveyis – Taro), an oral carbonic anhydrase inhibitor, has been approved by the FDA for treatment of primary hypokalemic and hyperkalemic periodic paralysis and related variants. Dichlorphenamide is the first drug to be approved in the US for this indication. It was approved as Daranide in 1958 for treatment of glaucoma, but had not been marketed since 2002.

Rapid exposure to altitudes more than 8,000 feet above sea level can cause serious medical problems. Since the last Medical Letter article on this subject (Vol. 30, page 89, 1988), some new information on prevention and treatment of these disorders has been reported.

View the Expanded Table: Some Drugs for Altitude Illness, Jet Lag, and Motion Sickness

Patients who receive pretravel advice can reduce their risk for many travel-related conditions. Vaccines recommended for travelers are reviewed in a separate issue.

Lantaoprost, a prostaglandin F2-alpha analog, has been approved by the FDA for topical treatment of elevated intraocular pressure in patients with open-angle glaucoma and ocular hypertension refractory to other drugs.

Dorzolamide hydrochloride (Trusopt - Merck), a thienothio-pyran-2-sulfonamide carbonic anhydrase inhibitor, was recently approved by the US Food and Drug Administration in a 2% ophthalmic solution for treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma.

Older patients are especially susceptible to drug-induced cognitive impairment. They are more likely to be taking multiple drugs, to have higher blood levels of those drugs because of renal or hepatic dysfunction, and to have pre-existing cognitive problems that make it difficult to detect the role of drugs causing new symptoms or making old ones worse.

As the weather becomes warmer, physicians may see more photosensitivity reactions due to systemic or topical drugs, perfumes, cosmetics or sunscreens. Even brief exposure to sunlight in warm or cold weather can cause intense cutaneous reactions in patients with drug-induced photosensitivity, and some patients may continue to be sensitive to sunlight long after stopping use of the offending agent.

The FDA has approved a once-daily extended-release (ER) formulation of the antiepileptic topiramate (Trokendi XR – Supernus) for initial monotherapy in patients ≥10 years old with partial onset seizures or primary generalized tonic-clonic seizures and for adjunctive therapy in patients ≥6 years old with partial onset seizures, primary generalized tonic-clonic seizures, or seizures associated with Lennox-Gastaut syndrome. Topiramate has been available for many years as an immediate-release (IR) formulation (Topamax, and generics) for the same indications in patients ≥2...

A reader has questioned why the label for the COX-2 selective NSAID celecoxib (Celebrex, and generics), which contains a sulfonamide moiety, states that it is contraindicated for use in patients with an allergy to sulfonamides, while the labels of some other sulfonamide drugs recommend either caution or no precautions at all. The concept of cross-reactivity among sulfonamide drugs, particularly between antibacterial and nonantibacterial sulfonamides, has been controversial for many years.