Belara Drug Interactions

Note: The prescribing information of concomitant medications should be consulted to identify potential interactions.
Pharmacodynamic interactions: Concomitant use with the medicinal products containing ombitasvir/paritaprevir/ritonavir and dasabuvir, with or without ribavirin, or glecaprevir/pibrentasvir may increase the risk of ALT elevations (see Contraindications and Precautions).
Therefore, Belara-users must switch to an alternative method of contraception (e.g., progestagen-only contraception or non-hormonal methods) prior to starting therapy with this combination drug regimen. Belara can be restarted 2 weeks following completion of treatment with this combination drug regimen.
Pharmacokinetic interactions: Effects of other medicinal products on Belara: Interactions can occur with drugs that induce microsomal enzymes which can result in increased clearance of sex hormones and which may lead to breakthrough bleeding and/or oral contraceptive failure.
Management: Enzyme induction can already be observed after a few days of treatment. Maximal enzyme induction is generally seen within a few weeks. After the cessation of drug therapy enzyme induction may be sustained for about 4 weeks.
Short-term treatment: Women on treatment with enzyme inducing drugs should temporarily use a barrier method or another method of contraception in addition to the COC. The barrier method must be used during the whole time of the concomitant drug therapy and for 28 days after its discontinuation.
If the drug therapy runs beyond the end of the tablets in the COC pack, the next COC pack should be started right after the previous one without the usual tablet-free interval.
Long-term treatment: In women on long-term treatment with enzyme-inducing active substances, another reliable, non-hormonal, method of contraception is recommended.
The following interactions have been reported in the literature.
Substances increasing the clearance of COCs (diminished efficacy of COCs by enzyme induction), e.g.: Barbiturates, bosentan, carbamazepine, barbexaclone, phenytoin, primidone, modafinil, rifampicin, rifabutin, and HIV medication ritonavir, nevirapine, and efavirenz and possibly also felbamate, griseofulvin, oxcarbazepine, topiramate and products containing the herbal remedy St. John's Wort (Hypericum perforatum).
The following medicinal products/active substances may reduce the serum concentrations of ethinylestradiol: All medicines that increase gastrointestinal motility (e.g. metoclopramide), or impair absorption (e.g. activated charcoal).
Substances with variable effects on the clearance of COCs: When co-administered with COCs, many combinations of HIV-protease inhibitors and non-nucleoside reverse transcriptase inhibitors, including combinations with HCV inhibitors can increase or decrease plasma concentrations of estrogen or progestins. The net effect of these changes may be clinically relevant in some cases.
Therefore the prescribing information of concomitant HIV/HCV medications should be consulted to identify potential interactions and any related recommendations. In case of any doubt, an additional barrier contraceptive method should be used by women on protease inhibitor or non-nucleoside reverse transcriptase inhibitor therapy.
The following medicinal products/active substances may increase the serum concentration of ethinylestradiol: active substances that inhibit the sulphation of ethinylestradiol in the intestinal wall, e.g. ascorbic acid or paracetamol; atorvastatin (increases the AUC of ethinylestradiol by 20%); active substances that inhibit microsomal enzymes in the liver, such as imidazole-type antimycotics (e.g. fluconazole), indinavir or troleandomycin.
Effects of Belara on other medicinal products: By inhibiting the hepatic microsomal enzymes thus consequently raising the serum concentration of active substances such as diazepam (and other benzodiazepines metabolised by hydroxylation), ciclosporin, theophylline and prednisolone.
By inducing hepatic glucuronidation thus consequently reducing serum concentrations of e.g. lamotrigine, clofibrate, paracetamol, morphine and lorazepam.
Insulin or oral antidiabetic requirements may need to be altered due to effects on glucose tolerance (see Precautions).
This may also apply to medicines taken recently.
The summary of product characteristics of the prescribed medicinal product should be checked for possible interactions with Belara.
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, e.g. corticosteroid-binding globulin and lipid/lipoprotein fractions, parameters of carbohydrate metabolism and parameters of coagulation and fibrinolysis. Changes generally remain within the normal laboratory range.