Why should loperamide hydrochloride be used with caution in people with hepatic impairment?

Imodium Instants (loperamide hydrochloride) requires caution in hepatic impairment because reduced first-pass metabolism may cause relative overdose and CNS toxicity, although pharmacokinetic data are unavailable in these patients, and its benzyl alcohol content poses a risk of accumulation and toxicity (metabolic acidosis).