Usefulness of serum concentration measurement for acute pentobarbital intoxication in patients.

Toxicokinetic parameters were analyzed in 25 patients who were acutely intoxicated with pentobarbital. The serum pentobarbital concentrations were at hypnotic / therapeutic levels (1- 10 microg/mL) in 11 patients, at toxic levels (10-24 microg/mL) in 10 patients, and at lethal levels (>24 microg/mL) in 4 patients. One fatal case was encountered with a serum pentobarbital concentration of 37.27 microg/ mL. The relationships between serum pentobarbital concentrations and the drug, the induced toxic symptoms, such as respiratory / cardiac depression and hypotension, were in good correlation. The therapy of direct hemoperfusion carried out for many pentobarbital-intoxicated patients was highly effective.

[Serum fenitrothion concentration and toxic symptom in acute intoxication patients].

The serum drug concentrations were measured by HPLC or GC/MS in 15 patients of acute fenitrothion (MEP), an organophosphorus insecticide, intoxication. There was no fatal case. The patients were admitted 0.5 approximately 12 hours after the ingestion of 5 approximately 50g MEP. The range of serum MEP concentrations were from undetectable level (< 0.01 microg/mL) to 9.73 microg/mL. Toxic symptoms were correlated with the serum MEP levels. About < 7 microg/mL of the serum MEP levels associated with mild cases and about > 7 microg/mL associated with serious cases. The elimination curves in mild cases were successfully simulated by the one-compartment model and the elimination half-lives (T1/2) were 9.9 +/- 7.7hr (mean +/- S.D.). The serum MEP concentrations declined below the detectable level in 48hr. The elimination curves in two serious cases were successfully simulated by the two-compartment model. The T1/2 in the alpha phase were 5.3hr and 6.7hr (under the direct hemoperfusion), and the T1/2 in the beta phase were 35hr and 52hr. The serum MEP concentrations declined below the detectable level in 300hr.