Incidence and patterns of hemolytic anemia in acute dapsone overdose.

BACKGROUND: Hemolytic anemia is one of the complications related to the chronic consumption of dapsone. However, in acute dapsone overdose, there have been few case reports regarding hemolytic anemia. Herein, we reported the prevalence and patterns of hemolytic anemia in acute dapsone overdose, and compared clinical features including mortality in the non-hemolytic anemia and the hemolytic anemia groups. METHODS: We conducted a retrospective review of 43 consecutive acute dapsone overdose cases that were diagnosed and treated at the emergency department of the Wonju Severance Christian Hospital between January 2006 and January 2014. RESULTS: There were 13 male patients (30.2%) and the ages of all patients ranged from 18 to 93 years with a median of 67 years. The ingested dose varied from a minimum of two 100-mg tablet to a maximum of twenty five 100-mg tablets. All patients had methemoglobinemia irrespective of the presence of hemolytic anemia. Among 43 patients, 30 patients (69.8%) were shown to have hemolytic anemia and hemolytic anemia developed the day after admission and persisted for more than 6 days after admission. Even though mortality rate was not significantly higher in the hemolytic anemia group, the hemolytic anemia group had significantly longer total admission and intensive care unit admission stays than the non-hemolytic group. CONCLUSIONS: A significant proportion of the patients with acute dapsone overdose is associated with occurrence of hemolytic anemia. Hemolytic anemia may be developed the day after admission and persisted for more than 6 days after admission. Therefore, monitoring of serum hemoglobin level is necessary.

Effectiveness of hemodialysis in acute dapsone overdose-a case report.

The use of dapsone is increasing even though overdose is rarely reported and physicians must be aware of its toxicity and management. Mortality can occur due to methemoglobinemia and hemolytic anemia. Although activated charcoal and methylene blue are recommended, the use of hemodialysis is reported only in few studies. Literature on the kinetic profile indicates that 50% to 80% of dapsone is protein bound and indicates a possibility to dialyze the unbound form. This study describes a case of deliberate severe dapsone overdose with cyanosis, methemoglobinemia, and hemolytic anemia, which improved after repetitive hemodialysis.

Optical coherence tomographic evaluation of macular infarction following dapsone overdose.

A 16-year-old girl had decrease in vision following dapsone overdose. This case demonstrated optical coherence tomography (OCT) evaluation of macular infarction following dapsone poisoning. OCT showed characteristic serial changes as Stage 1: Cystic macular edema, Stage 2: Resolving cystic change and Stage 3: Foveal atrophy. Hence, OCT could show the progression of foveal atrophy from cystic macular edema following dapsone poisoning.

Unexplained acute severe methaemoglobinaemia in a young adult.

This report describes the case of an otherwise healthy young adult female, who presented with a 12-h history of progressive bluish discolouration of lips and limbs. She denied ingesting or inhaling any drug or substance. A high PaO2 in the presence of 'cyanosis' and 'dark blood' led to suspicion of methaemoglobinaemia. Co-oximetry revealed the methaemoglobin level to be 47%. A urinary screen for drugs of abuse was negative and blood methaemoglobin reductase activity was within the normal range. The aetiology was traced to dapsone detected in the urine by gas chromatography/mass spectrometry. The therapeutic and diagnostic approach in such patients is discussed.

Clinical and laboratory parameters in dapsone acute intoxication.

OBJECTIVE: To determine the severity of dapsone (DDS) acute intoxication - an uncommon medical event - using clinical and laboratory parameters. METHODS: Two hundred and seventy four patients with acute DDS intoxication, aged 1 month to 50 years old, were studied and classified into four age groups. Clinical evaluation was assessed through a protocol and correlated with laboratory parameters. Spectrophotometric methods were used to analyze methemoglobinemia (MHbp) and dapsonemia (DDSp). RESULTS: The most prevalent clinical sign of intoxication was cyanosis, seen in 65.7% of the patients and in 100% of children less than 5 years of age. According to laboratory criteria, MHbp-related severe clinical intoxication was seen in 56.2% and DDSp-related occurred in 58% of the patients. Regarding DDSp, intoxication was considered severe when 20 tablets (100 mg each) were ingested, a median of 29 microg/ml. Regarding MHbp, intoxication was severe when 7.5 tablets were ingested, a median of 38% of the total Hb. The correlation between MHbp and DDSp was statistically significant (n=144, r=0.32, p<0.05). Negative correlation was observed between MHbp and the time elapsed since DDS intake (n=124, r=-0.34, p<0.001). There was also a negative correlation between DDSp and the time elapsed since DDS intake (n=63, r=-0.35, p<0.0001). CONCLUSIONS: Longitudinal analysis showed a significant association between methemoglobinemia and the time elapsed after the intake (t), according to the equation: Dapsonemia = 12.9256 - 0.0682t + 0.234 methemoglobinemia

Dapsone maculopathy.

After the injection of about 10 gm of dapsone, a 38-year-old male showed a whitish-yellow patch in the macular region of both eyes, with decreased visual acuity of the counting finger in the right and 0.04 in the left eye. Two weeks after the start of systemic steroid therapy the patch disappeared, and on follow-up at 11 months, visual acuity was 0.02 in the right and 0.08 in the left eye, with macular degeneration and foveal nonperfusion. This retinal damage seems to be ischemic in origin and to be caused by a combination of acute severe peripheral hypoxemia and the vascular obstructive effect of red cell fragmentation resulting from massive hemolysis.

Deliberate self-poisoning with dapsone. A case report and summary of relevant pharmacology and treatment.

We report the case of a 14-year-old girl who deliberately ingested 8-9 g of dapsone and presented with severe methaemoglobinaemia and altered mental status. Prompt treatment with repeated doses of methylene blue and organ support brought about control of the methaemoglobinaemia and averted organ failure.

Combined dapsone and clofazimine intoxication.

We report clinical findings and pharmacokinetic data regarding a combined dapsone and clofazimine intoxication in a man, who ingested 50 tablets of dapsone (100 mg) 20 capsules of clofazimine (100 mg) and two tablets of rifampicin (600 mg). Oral administration of activated charcoal (50 grams) and sodium sulphate (20 grams) after gastric lavage resulted in an elimination half-life in plasma of 11.1 and 10.8 h for dapsone and its main metabolite, monoacetyldapsone, respectively. A rapid initial decrease of the plasma concentration of clofazimine was observed after gastric lavage and administration of activated charcoal and sodium sulphate. 15 h after this treatment, clofazimine plasma levels remained relatively constant. Dapsone-induced methaemoglobinaemia (48% at admission) was treated successfully with methylene blue.

A case of acute dapsone poisoning: toxicological data and review of the literature.

A case of nonfatal, acute poisoning following the ingestion of an undetermined amount of dapsone (DDS) in a 49-year-old woman is presented. The clinical features were dyspnea and deep cyanosis. Methemoglobinemia was 39.0% on admission. DDS was identified and quantitated in blood samples taken on the third day (sample A) and fifth day (sample B) in the hospital using a high-performance liquid chromatographic technique with diode-array detection. DDS concentrations were 26.99 and 8.40 micrograms/mL in samples A and B, respectively. Results are discussed in the light of an extensive review of the literature (1950-1993) available on DDS poisonings.