Interactions with other medicines and products
Interaction Scope
Medicinal product categories with documented interactions:
Hepatitis C combination drug regimens, Anticonvulsants, Antibiotics, Herbal Products, Bile Acid Sequestrants, Statins, and Corticosteroids.
Specific interacting medicines (if explicitly listed):
Ombitasvir/Paritaprevir/Ritonavir, Rifampin, Phenytoin, St. John's wort, Colesevelam, Atorvastatin, and Lamotrigine.
Mechanistic basis of interactions (only if stated in label):
Microsomal enzyme induction, CYP3A4 inhibition, absorption interference, and induction of glucuronidation.
Timing-based interaction rules (if applicable):
Colesevelam must be administered 4 or more hours apart. Incomplete absorption may occur if severe vomiting or diarrhea happens within 3 to 4 hours of tablet intake.
Population-specific interaction notes (if applicable):
Not explicitly documented as a population-specific interaction severity in the core regulatory label.
Interaction-related restrictions:
Co-administration with certain Hepatitis C drug combinations is formally contraindicated.
Interaction Classifications (High-Level)
Interaction severity classification (as defined in official documents):
Contraindicated Combinations, Clinically Significant Interactions with Reduced Efficacy Risk, and Interactions with Increased Exposure.
Regulatory basis (EMA / FDA / etc.):
Information is based on regulatory documents from national and international government health authorities.
Interaction-context constraints (as defined in official documents):
Primarily involves co-administration with products that are inducers or inhibitors of hepatic metabolic enzymes.
Resulting Interaction Structure
Official interaction statements:
- Co-administration with certain Hepatitis C regimens is contraindicated due to the potential for elevated liver enzymes.
- Agents causing microsomal enzyme induction (e.g., Rifampin, Phenytoin) significantly decrease hormone exposure, potentially leading to diminished efficacy.
- Inhibition of CYP3A4 by medicines or substances (e.g., Azole antifungals, Grapefruit juice) causes an increase in the systemic exposure of the hormonal components.
- The contraceptive affects other medicines by decreasing the plasma concentration of Lamotrigine and increasing the concentration of Corticosteroids.
- The absorption interference caused by Colesevelam necessitates a minimum 4-hour separation in administration time.
Connection to the overall interaction profile (2–4 sentences):
Regulatory documents define the product’s interaction structure primarily around pharmacokinetic mechanisms, detailing how other medicines alter the concentration of the contraceptive hormones via enzyme induction or inhibition. The profile also establishes absolute contraindications for certain Hepatitis C regimens and specifies timing requirements for agents that interfere with absorption.