The FDA has approved Diclegis (Duchesnay), a fixed-dose, delayed-release combination of the H1-antihistamine doxylamine and the vitamin B6 analog pyridoxine, for treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management. It is only available by prescription. Doxylamine and pyridoxine, both currently available over the counter, were previously available by prescription in a fixed-dose combination (Bendectin) for morning sickness. Bendectin was voluntarily withdrawn in the US in 1983 because of claims of teratogenicity that have since been...

Betaine (Cystadane - Orphan Medical), an orphan drug, has recently been marketed for treatment of homocystinuria, a genetic disorder. Patients with homocystinuria frequently have premature atherosclerosis and thromboembolism, and may also have lens dislocations, skeletal abnormalities and mental retardation (SH Mudd et al in CR Scriver et al, eds, The Metabolic and Molecular Bases of Inherited Disease, 7th ed, New York:McGraw Hill, 1995, page 1279).

High plasma homocysteine concentrations, like high cholesterol, have been associated with an increased risk of cardiovascular disease and death (O Nygσrd et al, N Engl J Med 1997; 337:230; RS Vasan et al, JAMA 2003; 289:1251). In one meta-analysis, 25% lower plasma homocysteine concentrations were associated with 11% less coronary heart disease and 19% less stroke (Homocysteine Studies Collaboration, JAMA 2002; 288:2015). Should we be trying to lower serum homocysteine concentrations in our patients?

In a clinical trial conducted by the CDC's Tuberculosis Trials Consortium in collaboration with the NIH-funded AIDS Clinical Trials Group, a new 4-month regimen for treatment of drug-susceptible pulmonary tuberculosis was found to be noninferior to 6 months of standard treatment.

Tuberculosis (TB) is still a common cause of death worldwide, and the prevalence of drug-resistant TB poses challenges to its treatment and control. Guidelines with detailed management recommendations are available from the American Thoracic Society, Centers for Disease Control and Prevention (CDC) and Infectious Diseases Society of America (IDSA).

Many patients ask their physicians whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamin supplements.

Many patients ask their healthcare providers whether they should take vitamins. Since the last Medical Letter article on this subject, more data have become available on the benefits and risks of taking vitamins.