While HAART remains the main course of any treatment menu for CMC, experimental approaches may be
While HAART remains the main course of any treatment menu for CMC, experimental approaches may be useful on the side or even alone. Some block toxins pumped out by HIV-infected immune cells that likely cause neuron death; others protect the neurons from the damage done by those poisons.
- Memantine, a drug approved in Germany to treat Parkinson's disease and dementia in the elderly, is thought to work by blocking the neurotoxin quinolinic acid. A federal trial for people with CMC is nearing completion.
- Lexipasant, an experimental drug believed to block another neurotoxin, platelet activating factor, showed a trend toward cognitive improvements in a small study of people with CMC. A larger trial by DevCo begins soon.
- CPI-1189 has been shown to counter tumor necrosis factor (TNF), a chemical secreted by activated immune cells that can injure neurons. A federal trial of this drug for CMC was recently concluded, and results are due soon.
- Antioxidants are believed to protect neurons from injury by reducing levels of cell-damaging "free radicals," which are produced by the immune system's anti-HIV response and implicated in similar conditions such as Alzheimer's. Selegiline (a.k.a deprenyl), approved for Parkinson's, has demonstrated improvements in CMC symptoms in two small studies; a larger federal trial of the patch version is now enrolling. Gingko biloba, an herbal extract, has proved effective in rolling back symptoms of early-stage Alzheimer's dementia. Some practitioners have reported benefits for their patients with CMC.
- Peptide T, the first computer-designed antiretroviral and the first HIV fusion inhibitor, has been shown to prevent neuron death by blocking gp120, a potent HIV toxin; the drug also reduces TNF. Results of a federal trial published in 1998 showed that HIVers with CMC who took Peptide T for six months had "overall cognitive improvement," while "overall deterioration was more common among the placebo group." But a widely publicized 1995 federal press release based on incomplete results of the same study claimed "there was no evidence that Peptide T had an effect."
- Nimodipine (Nimotop), a calcium-channel blocker approved for treating cerebral
hemorrhages, was thought to counteract the toxic effects of gp120, but has proved disappointing as a CMC treatment.