Pharmacokinetics of Trimeprazine in Children

Abstract

The pharmacokinetics of trimeprazine (alimemazine) were studied over 24 hr in six children after a recommended preanaesthetic oral dose of 3 mg.kg-1. The degree of sedation before anaesthesia was evaluated. Median maximal venous blood drug concentration was 0.357 mumols.1(-1), 1-2 hr after oral ingestion, half-life 6.8 hr and AUC0-infinity h 2.758 mumols.1(-1) hr. Assuming 100 per cent bioavailability, blood clearance was estimated to median 3.7 1.kg-1.hr-1. Trimeprazine concentrations in cerebrospinal fluid (CSF) and in venous blood were compared in three other children, measured by gas chromatography. No trimeprazine was detected in the cerebrospinal fluid. We found a rough correlation between preanaesthetic sedation and blood trimeprazine concentrations. The kinetic parameters showed substantial interindividual differences, and accordingly, major interindividual variations in drug response might be anticipated even on standardized dosage regimens.

Psychotropic drug use among 0–17 year olds during 2004–2014: a nationwide prescription database study

“…However, frequent use of alimemazine as a hypnotic in children has been questioned for several reasons [ 15 ]. Alimemazine is not licensed or recommended for use in children less than 2 years old because of indications of highly variable pharmacokinetics [ 24 ], heavy hangovers as a commonly reported side effect [ 25 – 27 ], and a few reports of fatal adverse reactions [ 28 – 32 ]. Although not commonly conducted in children, a few small randomized controlled trials have explored the hypnotic effect of alimemazine [ 33 – 36 ].…”

Reducing children's fear when undergoing painful procedures.

“…Any medication that will help reduce this anxiety may increase cooperation and allow better treatment. Sedatives, such as Trimeprazine have been used but their effect has been limited (Sponheim et al, 1990). Furthermore, it is not sedation but anxiolysis that is the aim.…”

Paediatric sedation for imaging is safe and effective in a district general hospital

“…[29][30][31] Two groups have reported a success rate of 85% for imaging acquisition when alimemazine was combined with either chloral hydrate or papaveretum (a mixture of opioids). 12,32 The pharmacokinetics of alimemazine are well studied, showing a maximal venous blood drug concentration 1-2 h after ingestion and with a half-life of 6.8 h. 33 A survey of parents showed a median time of "return to normality" of the child of 21.5 h when chloral hydrate and alimemazine were used together. 20 Our hospital is a small district general hospital (DGH), with approximately 300 scans (CT, MR and NM) being performed on paediatric patients each year.…”