Acute dapsone intoxication: The dosage of activated charcoal and methylene blue

Chung,  Sung Pil; Hwang,  Tae Sik; Choi,  Sung Wook; Kim,  Seung Ho; Lee,  Hahn Shick

J Korean Soc Emerg Med > Volume 8(2); 1997 > Article

Original Article

Journal of The Korean Society of Emergency Medicine 1997;8(2): 277-282.

Acute dapsone intoxication: The dosage of activated charcoal and methylene blue

Sung Pil Chung, Tae Sik Hwang, Sung Wook Choi, Seung Ho Kim, Hahn Shick Lee

ABSTRACT

BACKGROUND: Methemoglobinemia(MetHb) induced by dapsone overdose is not uncommon in Korea, especially in rural area. For treatment of dapsone-induced methemoglobinemia, methylene blue(MB) and activated charcoal(AC) should be used. To date, no reports have compared the amount of MB used between MB alone with MB & AC combined group(MB+AC). And also between moderate (MetHb<35%) and severe (MetHb>35%) intoxicated group defined by initial MetHb level. Authors hypothesized that less amount of MB can be used if MB and AC was used together and larger amount of MB is necessary to reduce MetHb level to asymptomatic level in severely intoxicated group.
METHODS:
From Jan 1990 to Dec 1996, a total of 54 patients who received treatment for dapsone intoxication were subject of study, The study was done retrospective chart analysis for initial MetHb level, total amount of MB and AC. Wilcoxon rank sum test and Chi-sqiare test was used to compare the total dosage of MB used for each group. Linear regression analysis was used between initial MetHb and the total amount of MB. Results were considered statistically significant when p<0.05.
RESULTS:
For MB alone and MB+AC group, the differences in total amount of MB used were statistically significant with mean dosage of 7.14+/-1.1mg/kg and 4.28+/-0.7mg/kg, respectively. And total amount of MB used between moderate and severe intoxicated group, the differences were statistically significant with mean dosage of 5.16+/-1.1mg/kg vs. 10.98+/-1.9mg/kg, respectively. There was significant correlation between initial MetHb level (X) and the amount of methylene blue (Y), Y=0.3X-2.42 (r2=0.41, p=0.0001) in MB alone, Y=0.186X-1.95(r2=0.21, p=0.034) in MB+AC respectively.
CONCLUSION:
For methemoglobinemia induced by dapsone, total amount of MB can be reduced especially in severe Intoxicated group if AC use was combined in treatment modality. There was significant correlationship between initial MetHb level and total amount of MB used.