A synthetic form of the protein apoaequorin is the active ingredient in the over-the-counter dietary supplement Prevagen (Quincy Bioscience), which is heavily marketed to improve memory.

A reader asked us to review use of the phosphodiesterase-5 (PDE5) inhibitor sildenafil for treatment of Alzheimer's disease (AD).

Sumatriptan (soo ma trip' tan; Imitrex - Glaxo), a serotonin (5-HT) agonist, is now available in Canada and may soon be available in the USA for oral or parenteral treatment of migraine headache. The parenteral formulation is designed for patients to inject themselves subcutaneously. Sumatriptan is not recommended for prophylactic use.

Aspirin is now widely used for antithrombotic prophylaxis in patients who have had angina pectoris or a myocardial infarction and has also been tried in healthy people to prevent myocardial infarction. Recent studies have focused on increasingly lower doses of the drug. The use of aspirin in patients who have had transient ischemic attacks or strokes will not be discussed here.

The FDA has approved the use of tranexamic acid (Lysteda – Ferring), an oral antifibrinolytic, for treatment of menorrhagia. Tranexamic acid has been used for this purpose in Europe for decades, and is available without a prescription in some countries. It has been available in the US since 1987 for use with coagulation factors in patients with hemophilia undergoing dental extractions.

Flosequinan (Manoplax - Boots), a fluoroquinolone derivative, is now available in the USA for treatment of congestive heart failure. Labeling approved by the US Food and Drug Administration recommends the drug only for patients who cannot tolerate or have not responded adequately to an angiotensin-converting enzyme (ACE) inhibitor.

Aprotinin (Trasylol - Miles), an inhibitor of fibrinolysis first identified in 1930, was recently approved by the US Food and Drug Administration for intravenous use in high-risk coronary artery bypass graft (CABG) surgery to decrease bleeding and the need for transfusion. Inhibitors of fibrinolysis previously available in the USA include aminocaproic acid (Amicar, and others) and tranexamic acid (Cyklokapron - Medical Letter, 29:89, 1987).

Reteplase (Retavase - Boehringer Mannheim), a recombinant protein derivative of human tissue plasminogen activator (t-PA), has been marketed in the USA for thrombolysis in patients with acute myocardial infarction.

Lipoprotein associated phospholipase A₂ (Lp-PLA₂), an enzyme involved in the repair of oxidative damage to lipoproteins, causes release of inflammatory mediators associated with atherosclerosis. A new assay, PLAC (diaDexus, Inc.), is now available to measure Lp-PLA₂ levels. C-reactive protein (CRP), another inflammatory mediator, appears to be a biomarker for coronary disease (MH Shishehbor et al, Cleve Clin J Med 2003; 70:634). The role of Lp-PLA₂ testing in determining cardiovascular risk is less clear.

The FDA has approved an oral solution of the nonselective beta-adrenergic blocker propranolol (Hemangeol – Pierre Fabre) for treatment of proliferating infantile hemangiomas.