Lenzetto Drug Interactions

The metabolism of estrogens may be increased by concomitant use of substances known to induce drug-metabolising enzymes, specifically cytochrome P450 enzymes, such as anticonvulsants (e.g. phenobarbital, phenytoin, carbamazepine) and anti-infectives (e.g. rifampicin, rifabutin, nevirapine, efavirenz).
Ritonavir and nelfinavir, although known as strong inhibitors, by contrast exhibit inducing properties when used concomitantly with steroid hormones. (Traditional) herbal preparations containing St. John's wort (Hypericum perforatum) may induce the metabolism of estrogens (and progestagens).
At transdermal administration, the first-pass effect in the liver is avoided, and thus, transdermally applied estrogens (and progestagens) HRT might be less affected than oral hormones by enzyme inducers.
Clinically, an increased metabolism of estrogens and progestagens may lead to decreased effect and changes in the uterine bleeding profile.
No interaction studies have been conducted for Lenzetto.