Interactions
Topical
No interaction studies with the topical form have been performed. Mechanism of action
Description
Eflornithine is a "suicide inhibitor," irreversibly binding to ornithine decarboxylase (ODC) and preventing the natural substrate ornithine from accessing the active site (Figure 1). Within the active site of ODC, eflornithine undergoes decarboxylation with the aid of cofactor pyridoxal 5-phosphate (PLP). Because of its additional difluoromethyl group in comparison to ornithine, eflornithine is able to bind to a neighboring Cys-360 residue, permanently remaining fixated within the active site.During the reaction, eflornithines decarboxylation mechanism is analogous to that of ornithine in the active site, where transamination occurs with PLP followed by decarboxylation. During the event of decarboxylation, the fluoride atoms attached to the additional methyl group pull the resulting negative charge from the release of carbon dioxide, causing a fluoride ion to be released. In the natural substrate of ODC, the ring of PLP accepts the electrons that result from the release of CO2. The remaining fluoride atom that resides attached to the additional methyl group creates an electrophilic carbon that is attacked by the nearby thiol group of Cys-360, allowing eflornithine to remain permanently attached to the enzyme following the release of the second fluoride atom and transimination. Evidence
The reaction mechanism of Trypanosoma bruceis ODC with ornithine was characterized by UV-VIS spectroscopy in order to identify unique intermediates that occurred during the reaction. The specific method of multiwavelength stopped-flow spectroscopy utilized monochromatic light and fluorescence to identify five specific intermediates due to changes in absorbance measurements.
It is the most sensitive diagnostic test available and is used first line in all cases, but can miss balanced translocations and low-level mosaicism. Specific gene testing is available for certain disorders such as Rett syndrome, although these are expensive tests which arent widely available
Selective metabolic investigations may be useful in the absence of other identifiable causes, and the specific tests done will depend on the presentation. Inborn errors of metabolism causing metabolic disorders are rare and there are limited treatment options even if they are successfully diagnosed. Targeted MRI brain can be considered second line in selected patients, and is more likely to contribute to a diagnosis if the child has abnormal physical signs such as microcephaly, macrocephaly, a change in head circumference, focal neurological signs, or epilepsy.Neonatal screening is used in the UK (Guthrie test) and can diagnose certain inborn errors of metabolism before they cause significant developmental problems, with the aim to manage them so that no permanent damage occurs. Medium-chain acyl-CoA dehydrogenase deficiency
Homocysteinuria
Congenital hypothyroidism
Isovaleric acidaemia
Glutaricaciduria type 1
Maple syrup urine diseaseCanada, the US, and the Netherlands offer more extensive newborn screening, encompassing some other amino acid, organic, and urea cycle disorders

Management
The specific management of children with global developmental delay will depend on their individual needs and underlying diagnosis. Early intervention is essential to support the child to reach their full potential.