Potential for an external vaginal antiitch cream containing benzocaine to cause methemoglobinemia in healthy women.
OBJECTIVE
Our purpose was to assess the potential for an external vaginal antiitch cream (20% benzocaine, 3% resorcinol) to significantly increase levels of methemoglobin above normal in healthy women.


METHODS
Fifty-five women reporting external vaginal itch were recruited for the study. Each patient was used as her own control with methemoglobin levels being measured before and after use of the cream. Women were instructed to apply a 1-inch strip of cream by fingertip to the external genital area three or four times a day for 7 consecutive days.


RESULTS
There were no significant differences in methemoglobin levels before and after use or in levels from a subgroup of women aged > 50 years compared with levels in a younger population.


CONCLUSIONS
This preparation appears to be safe when used as directed; however, the results cannot be extrapolated to the very young. Nevertheless, lavish or frequent application over wide areas of excoriation might lead to toxic concentrations and methemoglobinemia. Therefore patients with serious vaginal disease should be advised against self-treatment beyond the 7-day limit imposed by the Food and Drug Administration for over-the-counter external analgesic medications.
Currie
J L
JL
Department of Obstetrics and Gynecology, Dartmouth Medical School, Lebanon, NH 03756, USA.
Mott
L A
LA
Pennisi
S C
SC
Smith
B D
BD
Smith
R P
RP
D000328:Adult; D000368:Aged; D001566:Benzocaine / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D008708:Methemoglobinemia / Q000139:chemically induced*; D008875:Middle Aged; D011539:Pruritus Vulvae / Q000188:drug therapy*; D014622:Vaginal Creams, Foams, and Jellies
D014622:Vaginal Creams, Foams, and Jellies; D001566:Benzocaine