3.4.5. Meclizine

Meclizine, an antihistamine drug, inhibits oxidative metabolism and apoptosis, and is neuroprotective in drosophila model. Energy metabolism deficits and neuronal degeneration are hallmarks of HD, so treatment with meclizine is a potential strategy, especially since it crosses the BBB [20,61] (Table 1 and Figure 2). There is no human clinical trial for this drug listed in clinicaltrials.gov.

#### *3.5. Targeting Transcriptional Dysregulation*

#### 3.5.1. Sodium Phenylbutyrate

Administration of sodium phenylbutyrate (an HDAC inhibitor) to N171-82Q symptomatic mice showed less brain atrophy and extended survival rates. Further, it increased and decreased histone acetylation and methylation, respectively, in the rodent brain. It also downregulated caspases involved in apoptosis [62]. A dose-response study highlighted that sodium phenylbutyrate was safe, secure, effective and well-tolerable in HD patients [97].
