[Secondary exposure to hormonal drugs]

Hormonal therapy is widely used to treat different conditions in humans; a well-known indication being the relief of menopausal symptoms in women. Transdermal delivery of hormonal drugs is common and may pose a risk to humans and animals through secondary exposure. This report raises awareness of risks associated with secondary exposure to transdermal hormone-containing drugs, based on evidence from spontaneous reporting of suspected adverse events. Clinical signs in humans included precocious puberty, unresolved virilisation, accelerated growth rate, alopecia, foetal death, and female infertility. In animals, clinical signs included persistent oestrus, poor growth rate and birth defects. Risks of secondary exposure must be acknowledged when prescribing hormonal drugs and as a possible aetiology of clinical signs in humans and animals.