Pseudomethemoglobinemia: a case report and review of sulfhemoglobinemia

OBJECTIVES

To see if methemoglobin could potentially be misdiagnosed and the limitation of present cooximeters.

PATIENT

A 17-year-old girl who overingested a combination of cimetidine, acetaminophen, ibuprofen, and naproxen in a suicide attempt.

METHOD

Use of pulse co-oximeters to aid in the diagnosis of suspected sulfhemoglobinemia.

RESULTS

Diagnosis of sulfhemoglobinemia achieved with final confirmation made with gas chromatography. Patient steadily improved with supportive care.

CONCLUSIONS

There is a potential for the diagnosis of methemoglobin with some of the limitations of present co-oximeters. The laboratory diagnosis of sulfhemoglobinemia can be difficult to make.

Cimetidine toxicity: an assessment of 881 cases

We reviewed 881 documented cimetidine overdoses. The data were compiled and analyzed retrospectively from 2,612,236 poisoning cases reported to two nationwide poison surveillance systems from 1978 through 1985. Only cases of cimetidine exposures without coingestants were included. Age, sex, symptom occurrence, treatment site, reason and route of exposure, and medical outcome data were evaluated. Eight hundred eighty-one cases met the criteria and were analyzed. Children between 12 and 35 months of age accounted for 43% of the cases and 97% of all exposures were acute. Intentional overdosage accounted for 21%; 76% were accidental in nature. Gastric emptying was performed in 34%. No symptoms were observed in 79% of the cases, which included ingestions of up to 15 g of cimetidine. Only three patients had moderate clinical manifestations. No patients had major medical complications and there were no fatalities. Even patients in the moderate category experienced no life-threatening toxic manifestations. Cimetidine appears to have an extremely high therapeutic index in both children and adults and demonstrates a remarkable safety profile following acute overdose.

Cimetidine: adverse reactions and acute toxicity

Recent reports of cimetidine toxicity are summarized. Summaries of specific cases and categorized according to cardiovascular, central nervous system, dermatologic, endocrine, gastrointestinal, hematologic, or renal toxicity, or overdosage. Adverse reactions reported secondary to cimetidine during its investigational period and shortly after marketing were minimal. In several studies in which over 1200 patients were treated with cimetidine, the incidences of adverse clinical symptoms was no higher than in the nearly 500 placebo-treated patients. However, subsequent reports indicate that elderly patients, patients with impaired renal function, and patients with liver disease appear quite susceptible to mental confusion. Potentially serious hematologic depression, cardiac depression, and hypersensitivity-type hepatitis have also been reported. As a result of the reports of impotence and oligospermia, controlled trials evaluating the effect of cimetidine on fertility in young men are needed.