gravir is the predominant circulating compound in plasma; renal elimination of unchanged active substance is low (< 1% of the dose). Fifty-three percent of total oral dose is excreted unchanged in the faeces. It is unknown if all or part of this is due to unabsorbed active substance or biliary excretion of the glucuronidate conjugate, which can be further degraded to form the parent compound in the gut lumen. Thirty-two percent of the total oral dose is excreted in the urine, mainly represented by ether glucuronide of dolutegravir (18.9% of total dose), N-dealkylation metabolite (3.6% of total dose), and a metabolite formed by oxidation at the benzylic carbon (3.0% of total dose).
In vitro experiments indicate that rilpivirine primarily undergoes oxidative metabolism mediated by the CYP3A system.
Drug interactions
In vitro, dolutegravir demonstrated no direct, or weak inhibition (IC50>50 μM) of the enzymes cytochrome P450 (CYP)1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 CYP3A, uridine diphosphate glucuronosyl transferase (UGT)1A1 or UGT2B7, or the transporters Pgp, BCRP, BSEP, OATP1B1, OATP1B3, OCT1, MATE2-K, MRP2 or MRP4. In vitro, dolutegravir did not induce CYP1A2, CYP2B6 or CYP3A4. Based on this data, dolutegravir is not expected to affect the pharmacokinetics of medicinal products that are substrates of major enzymes or transporters (see section 4.5).
In vitro, dolutegravir was not a substrate of human OATP 1B1, OATP 1B3 or OCT 1.
Elimination
Dolutegravir has a terminal half-life of ~14 hours. The apparent oral clearance (CL/F) is approximately 1L/hr in HIV-infected patients based on a population pharmacokinetic analysis.
The terminal elimination half-life of rilpivirine is approximately 45 hours. After single dose oral administration of 14C-rilpivirine, on average 85% and 6.1% of the radioactivity could be retrieved in faeces and urine, respectively. In faeces, unchanged rilpivirine accounted for on average 25% of the administered dose. Only trace amounts of unchanged rilpivirine (< 1% of dose) were detected in urine.
Special patient populations
Children
Neither Juluca nor the combination dolutegravir and rilpivirine as single entities have been studied in children. Dosing recommendations for paediatric patients cannot be made due to insufficient data (see section 4.2).
The pharmacokinetics of dolutegravir in 10 antiretroviral treatment-experienced HIV-1 infected adolescents (12 to <18 years of age and weighing ≥40 kg) showed that dolutegravir 50 mg once daily oral dosage resulted in dolutegravir exposure comparable to that observed in adults who received dolutegravir 50 mg orally once daily. The pharmacokinetics was eva luated in 11 children 6 to 12 years of age and showed that 25 mg once daily in patients weighing at least 20 kg and 35 mg once daily in patients weighing at least 30 kg resulted in dolutegravir exposure comparable to adults.
The pharmacokinetics of rilpivirine in 36 antiretroviral treatment-naïve HIV-1 infected adolescent subjects (12 to <18 years of age) receiving rilpivirine 25 mg once daily were comparable to those in treatment-naïve HIV-1 infected adults receiving rilpivirine 25 mg once daily. There was no impact of body weight on rilpivirine pharmacokinetics in paediatric subjects in study C213 (33 to 93 kg), similar to what was observed in adults.
Elderly
Population pharmacokinetic analysis using data in HIV-1 infected adults showed that there was no clinically re |
