Oral bioavailability of clonidine in children

Abstract

Clonidine administered with an apple fruit drink displays a variable and relatively slow absorption after oral administration (T(max) 1.04 h, C(max) 0.77 mcg·l(-1)). The oral bioavailability was 55.4%, which is less than reported in adults. Consequently, higher oral doses of clonidine (per kg) are required when this formulation is used to achieve concentrations similar to those reported in adults.

Pharmacokinetics and Pharmacodynamics of Orally Administered Clonidine: A Model-Based Approach

“…In our study, peak clonidine serum levels were reached at about 60 min post-dose and concentrations declined only slowly thereafter. This observation matches previously published data, which showed peak plasma concentrations at 60 min post-dose [13]. The large interindividual variation can in part be attributed to interindividual differences in oral bioavailability, which is estimated at 46.9-65.4% [13].…”

“…This observation matches previously published data, which showed peak plasma concentrations at 60 min post-dose [13]. The large interindividual variation can in part be attributed to interindividual differences in oral bioavailability, which is estimated at 46.9-65.4% [13]. It may also be due to the fact that an intravenous formulation was administered orally, which may have different pharmacological properties than tablets intended for oral administration.…”

A Review of the Rationale and Clinical Utilization of α2-Adrenoceptor Agonists for the Treatment of Attention-Deficit/Hyperactivity and Related Disorders

“…At least one population pharmacokinetic study has been published in children and adolescents (0-15 years of age) who received CLON-IR by intravenous, rectal, and epidural administration during anesthesia, which determined that by 1 year of age, 82% of the adult clearance rate is achieved (Potts et al 2007). Of significance is a recent finding of reduced bioavailability in children (3-10 years of age) who received CLON-IR orally (Larsson et al 2011). CLON-IR bioavailability was found to be significantly less (55.4% vs. 75-100% in adults) and more erratic (i.e., higher coefficient of variation) in children when compared with adults (Larsson et al 2011).…”

“…The fairly rapid decline in plasma level following a single acute dose is seen despite the fairly long half-life of GUAN-IR (i.e., *16 hours) (Shojaei et al 2006;Newcorn et al 2011b). Early pharmacokinetic studies in adults have shown that the bioavailability of oral CLON-IR is high, ranging from 75% to 100%, and that 40-75% is excreted unchanged in the urine (Davies et al 1977;Arndts 1983;Larsson et al 2011). These early studies of CLON-IR are complicated by the use of radioimmunoassay (Arndts 1983;Cunningham et al 1994) which exhibited cross-reactivity with at least one metabolite.…”

Unraveling Pharmacokinetics and Pharmacodynamics in Infants and Children

“…The oral bioavailability of clonidine is also poor (F = 0.55) in children 3-10 years. Consequently, larger oral doses (per kg) are required when this formulation is used to achieve concentrations similar to those reported in adults [78].…”