Lack of a clinically important pharmacokinetic interaction between sofosbuvir or ledipasvir and hormonal oral contraceptives norgestimate/ethinyl estradiol in HCV-uninfected female subjects.

This study evaluated the potential for a drug-drug interaction between HCV direct-acting antivirals sofosbuvir or ledipasvir and oral hormonal contraceptive (OC) norgestimate/ethinyl estradiol (norgestimate 0.18/0.215/0.25 mg with ethinyl estradiol 25 µg). This was a 112-day, open-label, fixed-sequence pharmacokinetic (PK) study in healthy female subjects that included a lead-in cycle (OC only; N = 21), cycle 1 (OC only; N = 15), cycle 2 (OC + sofosbuvir; N = 15), and cycle 3 (OC + ledipasvir; N = 15). Administration of sofosbuvir with OC did not alter PK of norelgestromin (primary norgestimate metabolite) or ethinyl estradiol. Small increases in norgestrel (secondary norgestimate metabolite) AUC(tau) (19%) and C(tau) (23%) with sofosbuvir were noted. Ledipasvir did not impact PK of norelgestromin or norgestrel but modestly increased ethinyl estradiol C(max) (40%). Sofosbuvir, GS- 331007 (predominant circulating metabolite of SOF), and ledipasvir PK were similar to historical data. Pharmacodynamic markers luteinizing hormone, follicle-stimulating hormone, and progesterone values were generally comparable in all cycles. No loss in contraceptive efficacy is expected upon administration of sofosbuvir or ledipasvir/sofosbuvir with oral contraceptives containing norgestimate and ethinyl estradiol. The use of sofosbuvir or ledipasvir/sofosbuvir FDC with oral contraceptives is permitted.

Zidovudine use but not weight-based ribavirin dosing impacts anaemia during HCV treatment in HIV-infected persons.

Anaemia during peginterferon (PEG-IFN) and ribavirin (RBV) therapy is common in human immunodeficiency virus/hepatitis C virus (HIV/HCV)-coinfected patients despite the use of lower doses of RBV than are recommended for HIV-seronegative persons. In addition, concurrent zidovudine (ZDV) may exacerbate the anaemia caused by PEG-IFN and RBV. We retrospectively analysed the incidence of anaemia, RBV dose reduction and epoetin-alpha (EPO) use among coinfected patients treated with PEG-IFN and weight-based RBV (800-1400 mg/day) who enrolled in two clinical trials and had haemoglobin (Hb) levels assessed at baseline and after 4 and/or 12 weeks of HCV treatment. Overall, 217 patients were included; pre-treatment Hb levels (mean 14.7 g/dL) were similar in all patients, including ZDV users (29% of patients). After 4 weeks of therapy, the mean Hb decline was greater among ZDV recipients (3.13 g/dL) compared with those on other anti-retroviral treatment (ART) (2.13 g/dL) or on no ART (1.47 g/dL) (P < 0.0001). RBV dose reduction and EPO use were more common in patients taking ZDV compared with those not taking ZDV (P < 0.0001). RBV dose was not associated with Hb reduction, RBV dose reduction or EPO use. Virologic response after 12 weeks of therapy and the treatment discontinuation rate did not differ by ZDV use. The use of ZDV but not weight-based RBV dosing was associated with an increased risk of anaemia, RBV dose reduction or EPO use in coinfected patients treated with PEG-IFN/RBV. However, ZDV use was not associated with higher rates of treatment discontinuation or lower early virologic response rates. HIV and hepatitis C care providers should be cognizant of these data.

The Pressure-Controlled Infusion System: a new instrument for closed-system surgery.

We present the new Pressure-Controlled Infusion System (PCIS), designed to automatically regulate intraocular pressure (IOP) during surgery. Studies were performed with rabbits in which we compared the true IOP during closed-system surgery using gravity-fed infusion with the automatic control provided by the PCIS. The results from irrigation/aspiration of the lens cortex, wound closure, and vitrectomy show that the PCIS performs two functions during closed surgery: it automatically maintains the baseline IOP at the pre-set level, and it dramatically decreases the pressure fluctuations that occur with gravity infusion.