Chen A1, Loquias EJ1, Roshan R, Levene R, Zelhof R, Hickey T, Cooney GA, Gonzalez F.
Although commonly administered in an impatient setting via the subcutaneous (SC) route, outside the hospice setting subcutaneous DPH has not been widely
used, primarily because of a handful of case reports published in the 1990s
that report skin necrosis following subcutaneous administration of DPH for local
anesthesia.
In this study a total of 648 diphenhydramine subcutaneous injections were administered
in 109 individual patients. None of the patients were reported to have an
adverse cutaneous reaction. The authors suggest that this review demonstrates that subcutaneous diphenhydramine injection is a safe
alternative to oral and other parenteral routes, and may be particularly
valuable in terminally ill patients, who are often unable to swallow and are
without IV access.