Weight, pregnancy and oral contraceptives affect intravenous paracetamol clearance in young women

OBJECTIVES

Because of the extensive variability in paracetamol clearance in young women, published data were pooled with newly collected observations in search of covariates of paracetamol pharmacokinetics (PK) within this specific population.

SUBJECTS AND METHODS

PK estimates and clinical characteristics [pregnant, weight, exposure to oral contraceptives (OC)] in young women following IV loading dose (2 g paracetamol) were pooled, using a non-compartmental linear disposition model in individual time-concentration profiles. Data were reported by median and range. Rank correlation was used to link clearance (l/h) to weight, Mann Whitney U test to compare clearance (l/h.m-2) between subgroups (pregnant, OC exposure). Finally, a multiple regression model with clearance (l/h) in all women and all non-pregnant women was performed.

RESULTS

Based on 73 paracetamol PK estimates, a 8-fold variability in clearance (range 7.1-62.2 l/h) was documented, in part explained by a correlation (r2=0.36) between clearance (l/h) and weight. Clearance (l/h and l/h.m-2) and distribution volume (l) at delivery (n=36) were higher compared to non-pregnant observations. In non-pregnant women, women on OC (n=20) had a higher paracetamol clearance (l/h.m-2) compared to women (n=17) not on OC (p = 0.023). Weight (p = 0.0043) and pregnancy (p = 0.02) were independent variables (r=0.56) of paracetamol clearance (l/h). In non-pregnant women, weight (p = 0.009) and OC exposure (p = 0.03) were independent variables (r=0.51).

CONCLUSIONS

Weight, pregnancy and OC result in higher clearance of IV paracetamol in young women. Besides compound specific relevance, these findings also unveil covariates of drug metabolism in young women.

Increased serum C-reactive protein concentration is associated with body mass index but not with glycated haemoglobin in patients with type 1 diabetes mellitus with body mass index within normal range

This study investigated whether serum C-reactive protein (CRP) concentration is increased in patients with type 1 diabetes mellitus with a normal body mass index (BMI) and whether BMI, glycated haemoglobin (HbA1c) and CRP are correlated in patients with type 1 diabetes. High-sensitivity CRP was determined by immunonephelometry and HbA1c by an immunoturbidimetric method in 30 patients with type 1 diabetes and 30 healthy individuals matched for age, sex and BMI. Median serum CRP concentration in patients with type 1 diabetes (1.34 mg/L) was significantly higher than healthy individuals (0.2 mg/L; p<0.0001). Positive correlation between CRP and BMI was observed (rho=0.598; p<0.0001), but no significant correlation was observed between CRP and HbA1c (rho=0.285; p=NS) in patients with type 1 diabetes. Increased CRP levels in type 1 diabetes patients do not appear to be associated with glycaemic control, and may reflect low-grade inflammation associated with atherosclerosis, as well as activation of innate immune activity.