Complementary and alternative medicines in the treatment of dementia: an evidence-based review.

Alternative medicines may have potential beneficial results in treating certain forms of dementia and related symptoms, as well as slowing disease progression. Alternative medicines may ameliorate disturbances in cognition, mood, sleep and activities of daily living. Primary mechanisms of action include modifications in neurotransmitter synthesis, inhibition of neurotransmitter reuptake and enzyme-induced neurotransmitter breakdown, antioxidant and anti-platelet activity, enhanced blood flow and glucose metabolism. Adverse events can include cardiovascular, gastrointestinal, mood, autonomic and dermatologic effects. However, adverse events, when reported represent, a small percentage of treated groups and direct links between adverse events and alternative therapies are tenuous. Many studies of alternative medicines in dementia are inconclusive and characterised by methodological deficiencies such as small sample sizes and inadequate controls. If alternative medicines can be shown to be efficacious using more rigorous experimental designs, both consumers and clinicians could avail themselves of a wider range of pharmacological substances that may offer the advantage of being better tolerated and exhibiting safer therapeutic margins than some allopathic medicines. While a number of complementary interventions have shown both strengths and weaknesses, huperzine A, levacecarnine and EGB 761, based on the overall quality of the studies, identified mechanisms of activity and safety profiles merit further examination in controlled clinical outcome studies.