Is Methylphenidate Safe in Pregnancy?

* The main factor controlling absorption from immediate release preparations is probably gastric emptying time, whereas for slow release preparations it is the programmed drug release and solution pattern:-
- Prolongation of gastric emptying during pregnancy, could increase the time to peak plasma dose for the immediate release form.

* Methylphenidate is metabolized through esterification by gut enzymes. P450 enzymes have a minimal metabolizing role and therefore increased activity of these enzymes in pregnancy is unlikely to cause any effect on methylphenidate plasma concentration.

* Changes in volume of distribution during pregnancy may affect therapeutic effects of methylphenidate, and adjustment of dose may be necessary depending on clinical response.

* Drugs that are more likely to cross the placenta are:
(a) not protein bound,
(b) have a molecular weight of < 500 Daltons (Da),
(c) have a long half-life,
(d) are lipid soluble and
(e) weak acids.

* Methylphenidate exhibits low plasma protein binding (approximately 15%) and, has a molecular weight of only 269.8 Da, but it has a short half-life (1.4–4.2 h) and is freely soluble in water.
Overall the chemical characteristics of methylphenidate suggest some possibility that it may be able to cross the materno-fetal barrier and reach the fetal circulation.

So Is Methylphenidate Safe in Pregnancy and Lactation ?

Source: Br J Clin Pharmacol. 2014 Jan; 77(1): 96–101.