According to theInstitute for Safe Medication Practices (ISMP),the abbreviation"HCTZ"forhydrochlorothiazidemay be misinterpreted as:

HCTZ (hydrochlorothiazide) is a diuretic, but the abbreviation can be confused with hydrocortisone (a corticosteroid).

To prevent errors, ISMP recommends writing out "hydrochlorothiazide" instead of using "HCTZ."

????Reference:ISMP Do Not Use List, PTCE Medication Safety Guidelines.