The pharmacokinetics of trimethobenzamide have been studied in healthy adult subjects. Following administration of 200 mg (100 mg/mL) Tigan IM injection, the time to reach maximum plasma concentration (Tmax ) was about half an hour, about 15 minutes longer for Tigan 300 mg oral capsule than an IM injection. A single dose of Tigan 300 mg oral capsule provided a plasma concentration profile of trimethobenzamide similar to Tigan 200 mg IM. The relative bioavailability of the capsule formulation compared to the solution is 100%. The mean elimination half-life of trimethobenzamide is 7 to 9 hours. Between 30 - 50% of a single dose in humans is excreted unchanged in the urine within 48 - 72 hours. The metabolic disposition of trimethobenzamide in humans is not known. Specifically, it is not known if active metabolites are generated in humans.
The purpose of this study was to compare the effect of the Z-track intramuscular injection technique with the effect of the stand and intramuscular injection technique on the severity of discomfort and lesions at the injection site. The subjects of the study were 20 patients with only early tuberculosis excluding another abnormalities (a skin rash, allergy to topical use of alcohol, jaundice, edema, neurosensory abnormality, coagulation defects, obesity and thin). Data collection was done from Feb. 1 to March 15, 1988 by means of Korean Pain Measurement Tool, Visual Analogue Scale, and Objective measures of injection site lesions. The results of this study were as follows: 1) Hypothesis 1; "The severity of subject discomfort is less following administration of the Z-track intramuscular injection technique than following administration injection technique." was not supported. 2) Hypothesis 2; "The degrees of severity subject discomfort is less following administration of the Z-track intramuscular injection technique than following administration of the standard intramuscular injection technique." was not supported. 3) Hypothesis 3; "The severity of injection sites lesions is less following administration of the Z-track intramuscular injection technique than following administration of the standard intramuscular injection techniques." was not supported. 4) The terms that were selected included factor II (mild-moderate pain) of Ratio Scale Measuring Pain using Korean Pain Terms. In conclusion; it was found that there was not a difference from the severity of subject discomfort between two groups, but the degrees of severity of subject discomfort about following administration of the Z-track intramuscular injection was tended to be declined. Therefore further studies suggest that the Z-track intramuscular injection technique can decrease the severity of discomfort in persons receiving frequently intramuscular injections. First of all, it is necessary to be developed an effect tool of dis comfort measurement for the intramuscular injection in Korean.