Synfonia Drug Interactions

Hepatic metabolism: Interactions can occur with drugs that reduce hepatic enzymes which can result in increased clearance of sex hormones (e.g. phenytoin, barbiturates, primidone, carbamazepine, oxcarbazepine, topiramate, felbamate, griseofulvin, rifampicin, HIV-medication (e.g. ritonavir, nevirapine) and possibly also and products containing the herbal remedy St. John's Wort (Hypericum perforatum).
Women on short-term treatment with any of the previously mentioned classes of medicinal products or individual active substances (hepatic enzyme-inducing medicine) should temporarily use a barrier method in addition to the combined oral contraceptives.
Influence of Synfonia on other medicinal products: Oral contraceptives may affect the metabolism of certain other active substances. Accordingly, plasma and tissue concentrations may either increase (e.g. ciclosporin) or decrease (e.g. lamotrigine).
Other interactions: In patients without renal insufficiency, the concomitant use of drospirenone and ACE-inhibitors or NSAIDs did not show a significant effect on serum potassium. Nevertheless, concomitant use of Synfonia with aldosterone antagonists or potassium-sparing diuretics has not been studied. In this case, serum potassium should be tested during the first treatment cycle.
Laboratory tests: The use of contraceptive steroids may influence the results of certain laboratory tests, including biochemical parameters of liver, thyroid, adrenal and renal function, plasma levels of (carrier) proteins.