1 research outputs found
Pharmacokinetics of rectal compared to intramuscular paracetamol in children undergoing minor surgery
Objectives : Although paracetamol is a widely accepted and safe
analgesic, guidelines regarding its definite analgesic dose are
lacking. This study was, therefore, undertaken to compare the
pharmacokinetics of paracetamol when administered by two routes, viz,
intramuscular and rectal, in children undergoing minor surgery.
Design : Randomized, controlled, assessor-blind, comparative clinical
trial. Materials and Methods: Following Institutional Ethics Committee
approval and valid consent, children undergoing minor surgery were
randomized to receive paracetamol either intramuscularly or rectally.
Blood samples were collected at fixed intervals for estimation of drug
levels. Results : Fifty children (43 boys, 7 girls; ages 3 to 12
years; weight 10 to 40 kg) were enrolled in the study. 26 patients were
randomized to receive paracetamol intramuscularly (mean dose 14.8
± 0.9 mg/kg) and 24 to receive the paracetamol as a rectal
suppository (mean dose 29.5 ± 1.4 mg/kg). Complete pharmacokinetic
analysis was possible in only 29 patients, as the blood samples of the
others were either not received or were inadequate for analysis. The
mean maximum plasma concentration (C max ) with rectal paracetamol (n =
13) was 6.04 ± 2.21 mg/ml with a T max of 2.5 ± 0.89 h, while
with intramuscular paracetamol (n = 16), the C max was 10.34 ±
7.09 mg/ml and the T max 1.47 ± 0.64 h. The area under the
concentration-time curve (AUC 0-12 ) was 42.26 ± 22.29
µg.h/ml and 43.60 ± 26.45 µg.hr/ml for rectal and
intramuscular paracetamol, respectively. Patients in the intramuscular
group needed rescue medication earlier as compared to those in the
rectal group (P < 0.05). Conclusion : Although the drug levels
achieved with rectal paracetamol were less than that achieved with
intramuscular administration, it was higher than the lower limit for
analgesic effect (3-5 µg/ml). Patients who received paracetamol
intramuscularly needed rescue medication earlier compared to those
receiving paracetamol rectally, indicating a more prolonged duration of
action with rectally administered paracetamol. Hence, rectal
paracetamol can be used as a safe, effective, and more acceptable
analgesic alternative in children