Healthy lifestyle is very important to maintaining cognitive function. Stress reduction, exercise, and social and intellectual stimulation are vital. Though not studied yet in HD, antidepressants are probably the drugs that give best benefit. This is certainly the case for Parkinson's.

Anticholinesterase drugs donepezil (Aricept®) and rivastigmine (Exelon®) have been studied in small groups of HD people. Neither drug gave significant benefit. Memantine (Namenda®) is presently in clinical trial for Huntington's, and of these three drugs, is the most likely to give benefit.

Memantine (Namenda®) This drug works by blocking glutamate action. Dosing starts at 5 mg/day for the first week, then increases by 5mg/day for the next 3 weeks (wait a week to increase each dose). The target dose is 20-30 mg/day in divided doses twice daily. Side effects include dizziness, headache, constipation, high blood pressure.

Rivastigmine (Exelon®) This drug is a cholinesterase inhibitor that is used in both Alzheimer's and Parkinson's. Dosing starts at 1.5 mg twice daily, doubling the dose every two weeks till reaching a maximum of 6 mg twice daily. Side effects include nausea, and stomach distress, diarrhea and fatigue. It should be taken with meals to decrease stomach upset.

Donepezil (Aricept®) This is a cholinesterase inhibitor. Dosing starts at 5 mg once daily. This dose can be increased to 10 mg/day after a wait of 3 weeks. It is best taken at bedtime to decrease side effects which include headache, diarrhea, fatigue, loss of appetite, dizziness, and fatigue.