Ortho Women's Health, a unit of Ortho-McNeil Pharmaceutical Inc., has updated the warnings section of the prescribing information for Ortho Evra (norelgestromin/ethinyl estradiol transdermal system).

According to a company release, the pharmacokinetic (PK) profile for the Ortho Evra patch is different from the PK profile for oral contraceptives in that it has higher steady state concentrations and lower peak concentrations. AUC and average concentration at steady state for ethinyl estradiol (EE) are approximately 60% higher in women using Ortho Evra compared with women using an oral contraceptive containing EE 35 micrograms.

In contrast, peak concentrations for EE are approximately 25% lower in women using Ortho Evra. Inter-subject variability results in increased exposure to EE in some women using either Ortho Evra or oral contraceptives. However, inter-subject variability in women using Ortho Evra is higher. In general, increased estrogen exposure may increase the risk of adverse events. However, it is not known if there are changes in the risk of serious adverse events based on the differences in pharmacokinetic profiles of EE in women using Ortho Evra compared with women using oral contraceptives containing 35 micrograms of EE.

Additional updates to the prescribing information for Ortho Evra include new language to the indications and usage, description, dosage and administration and clinical pharmacology sections.

The detailed patient labelling for Ortho Evra has also been revised to include new information in the description, other considerations before using Ortho Evra and how to use Ortho Evra sections. This labelling change is effective immediately.

Since the introduction of Ortho Evra in 2002, Ortho Women's Health has maintained an ongoing clinical development programme for Ortho Evra which is designed to further characterise the potential benefits and safety of this product. The company is conducting two epidemiological studies that were designed with input from the US Food and Drug Administration and are similar to those previously conducted with oral contraceptives. Results from an initial analysis of the first epidemiological study have been submitted to the FDA and also submitted for publication, added the release.

Ortho Evra has been used by more than five million women and remains a safe and effective product, when used according to the product's label. However, hormonal contraception is not suitable for all women. It is important that women speak with their healthcare professionals about what option is right for them.