Latrogenic Cushing’s syndrome by an interaction between cobicistat and fluticasone: a case report / Síndrome de Cushing yatrogénico asociado a la interacción entre cobicistat y fluticasona: caso clínico

We report a case of iatrogenic Cushing’s syndrome associated with an interaction between cobicistat and fluticasone in a seropositive woman treated with elvitegravir/cobicistat/emtricitabina/TAF (Genvoya®). This case highlights the importance to review interactions between antirretroviral therapy and other drugs, especially when antirretroviral scheme includes protease inhibitors enhanced with ritonavir or cobicistat. These enhancers interfere the cytochrome P-450 metabolic pathway. A large number of drugs are metabolized by cytochrome P-450 and may be altered by cobicistat or ritonavir. (AU)

Presentamos un caso de síndrome de Cushing asociado a la interacción entre cobicistat y fluticasona en una mujer seropositiva en tratamiento con elvitegravir/cobicistat/emtricitabina/TAF (Genvoya®). Este caso pone de manifiesto la importancia de la revisión de las interacciones entre el tratamiento antirretroviral y otros tratamientos concomitantes, especialmente cuando el esquema antirretroviral contiene inhibidores de proteasa potenciados con ritonavir o cobicistat. Esta potenciación afecta a la ruta metabólica mediada por el citocromo P450. Un elevado número de fármacos son metabolizados por el citocromo P450, y por tanto pueden verse afectados cuando se administran con ritonavir o cobicistat. (AU)

No progression of subclinical atherosclerosis in HIV-infected patients starting an initial regimen including tenofovir alafenamide/emtricitabine plus raltegravir, dolutegravir or elvitegravir/cobicistat during a two-year follow-up.

Objectives: Cardiovascular disease has become one of the most common comorbidities among HIV-infected patients, but available data about the correlation between antiretroviral drugs and progression rate of atherosclerotic disease are still limited. We evaluated the progression rate of carotid atherosclerosis in patients starting an initial antiretroviral regimen including one integrase strand transfer inhibitor (INSTI).Methods: Observational, prospective study involving HIV-1-infected, antiretroviral therapy-naive, adult patients who started an antiretroviral regimen including tenofovir alafenamide/emtricitabine (TAF/FTC) plus raltegravir (RAL group), elvitegravir/cobicistat (EVG/c group), or dolutegravir (DTG group). Patients with known cardiovascular disease or diabetes mellitus were excluded from the study. The progression rate of atherosclerosis has been assessed by carotid Doppler ultrasonography at baseline and after 24 months.Results: Overall, 102 patients were enrolled into the study: 73 males, with mean age of 48.7 years: 32, 36 and 34 patients were included in the RAL, EVG/c and DTG groups, respectively. The baseline features of the enrolled patients were comparable across the three groups. At 24 months, the mean intima-media thickness (IMT) increase at the carotid bifurcation was 0.026 mm in the RAL group, 0.029 mm in EVG/c group and 0.032 mm in DTG group. The mean IMT increases after 24 months were comparable across the three groups and statistically not significant in all the evaluated anatomical sites.Conclusions: The initial antiretroviral therapy with TAF/FTC plus RAL, EVG/c or DTG for 24 months led to a comparable and not significant effect on the progression rate of carotid atherosclerosis.

Iatrogenic Adrenal Insufficiency Secondary to Combination Therapy with Elvitegravir/Cobicistat/Tenofovir Disoproxil Fumarate/Emtricitabine and Interlaminar Triamcinolone Injection in an AIDS Patient.

We report the first identified case of suspected iatrogenic adrenal insufficiency after an interlaminar injection of triamcinolone acetonide while on concomitant Stribild (elvitegravir 150 mg/cobicistat 150 mg/tenofovir disoproxil fumarate 300 mg/emtricitabine 200 mg [EVG/c/TDF/FTC]). A 49-year-old female with HIV on EVG/c/TDF/FTC therapy presented to our endocrinology clinic to be evaluated for suspected Cushing syndrome. Prior to presentation, the patient had been given 2 interlaminar spinal injections of triamcinolone. Thereafter, she developed a swollen face, had unexplained weight gain, and fatigue. Cosyntropin stimulation test was positive for adrenal insufficiency. By applying the Naranjo Nomogram for Causality and the Drug Interaction Probability Scale to this drug-drug interaction, we calculated a score of 6 ( probable) and 5 ( probable), respectively. Symptoms resolved without further intervention. The EVG/c/TDF/FTC contains cobicistat, a strong cytochrome P450 3A4 (CYP3A4) inhibitor, which can potentiate drug interactions involving metabolizing of medications via this pathway. Clinicians are reminded to be vigilant while assessing the potential pharmacokinetic drug interactions not mentioned by the manufacturer.

Optimal HIV Postexposure Prophylaxis Regimen Completion With Single Tablet Daily Elvitegravir/Cobicistat/Tenofovir Disoproxil Fumarate/Emtricitabine Compared With More Frequent Dosing Regimens.

STRUCTURE: The study evaluated elvitegravir/cobicistat/tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) ("Quad pill") for postexposure prophylaxis (PEP). BACKGROUND: HIV-exposed individuals may benefit from PEP, but completion rates have been suboptimal because of regimen complexity and side effects. Newer antiretroviral combinations coformulated as single daily pills may optimize PEP adherence. SETTING: One hundred HIV-uninfected individuals who presented to a Boston community health center after an acute HIV sexual exposure were enrolled and initiated PEP with the daily, single-pill combination Quad pill for a 28-day course. METHODS: Side effects and medication completion rates from study participants were compared with historical controls who had used PEP regimens consisting of TDF/FTC daily and raltegravir twice daily, or earlier regimens of twice daily zidovudine (AZT)/lamivudine (3TC) and a protease inhibitor, using χ tests for independence. RESULTS: Of the 100 participants who initiated the Quad pill for PEP after a high-risk sexual exposure, 71% completed the 28-day Quad pill regimen, which was significantly greater than historical controls who used TDF/FTC and raltegravir (57%, P < 0.05) or AZT/3TC plus a protease inhibitor (39%, P < 0.001). The most common side effects reported by Quad pill users were as follows: abdominal discomfort or pain, gas or bloating (42%), diarrhea (38%), fatigue (28%), nausea or vomiting (28%), headache (14%), or dizziness or lightheadedness (6%). Most symptoms were mild, limited, and did not result in medication discontinuation. No participants became HIV infected. CONCLUSIONS: Fixed-dose combination of elvitegravir/cobicistat/TDF/FTC was safe and well tolerated for PEP, with higher regimen completion rates than more frequently dosed PEP regimens.

Evaluation of tolerability with the co-formulation elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate for post-HIV exposure prophylaxis.

BACKGROUND: The preferred regimen for HIV post-exposure prophylaxis (PEP) is based mainly on safety and tolerability because it is given to immunocompetent people without HIV infection for a limited time (28 days). The frequency of adverse events (AEs) may be > 60%. Although AEs are generally not severe, they can lead to lack of adherence and failure to complete the regimen. We evaluated the co-formulation elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (Stribild®) prescribed as one pill taken once daily for HIV PEP in terms of tolerability and adherence. METHODS: This was a prospective cohort study conducted in one hospital in Paris (April to December 2015. Each participant receiving the PEP treatment (FTC-150 mg/TDF-245 mg/elvitegravir-200 mg/cobicistat 150 mg once daily) at the pharmacy of the hospital were recruited consecutively. A clinical visit was planned at 8 weeks after sexual exposure. Reminders were sent to participants who missed the appointment. A standardized questionnaire was administered to evaluate completeness and tolerability at week 8. RESULTS: Overall, 284 participants (86% men; 80% MSM; median age 30 years) were prescribed Stribild®; 50 stopped after reassessment of risk. Among 234 participants who effectively received PEP, 215 (92%) completed 28 days of PEP with only three who switched from Stribild® to another PEP because of side effects. More than 60% of participants reported at least one AE, which were mild to moderate. Fatigue, central neurological and abdominal side effects were the most frequently reported. CONCLUSIONS: Stribild® seems to be a good option for HIV PEP due to the easiness of use, the side effects profile and the high completion rate.

Safety and Tolerability of Stribild in the Southeast United States.

PURPOSE: The purpose of this study is to assess postmarketing safety and tolerability of Stribild (elvitegravir [EVG]/cobicistat [COBI]/tenofovir disoproxil fumarate [TDF]/emtricitabine [FTC]). METHODS: A retrospective, pharmacoepidemiologic study in 2 outpatient HIV clinics in the Southeast United States was conducted among adults receiving EVG/COBI/TDF/FTC. We evaluated incidence and treatment-related adverse events, including change in serum creatinine (SCr). RESULTS: Patients were primarily treatment experienced (n = 173, 60%), African American (n = 210, 73%), and males (n = 187, 65%). One hundred ninety-five (68%) patients had any increase in SCr, and 65 (23%) had an increase of ≥0.3 mg/dL. Mean SCr change from baseline to peak was 0.2 mg/dL. Being treatment experienced (odds ratio [OR] = 2.21, 95% confidence interval [CI]: 1.12-4.38) was associated with SCr ≥0.3 mg/dL, while body mass index ≥30 kg/m(2) (OR = 0.41, 95% CI: 0.18-0.93) was protective. Twenty (7%) patients discontinued therapy, 3 due to acute kidney injury. CONCLUSION: Our results demonstrate limited adverse events and low discontinuation rates associated with EVG/COBI/TDF/FTC.

Pharmacokinetics of Co-Formulated Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Disoproxil Fumarate After Switch From Efavirenz/Emtricitabine/Tenofovir Disoproxil Fumarate in Healthy Subjects.

BACKGROUND: Elvitegravir (EVG), a HIV integrase inhibitor, is metabolized primarily by CYP3A, and secondarily by UGT1A1/3; Efavirenz (EFV), a HIV non-nucleoside reverse transcriptase inhibitor, is metabolized by Cytochrome P450 (CYP) 2B6 and induces CYP3A and uridine diphosphate glucuronosyltransferase (UGT) with residual effects post discontinuation because of long T1/2 (40-55 hours). This study evaluated the pharmacokinetics after switching from efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF) to elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF). METHODS: Healthy subjects (n = 32 including n = 8 CYP2B6 poor metabolizers) received EVG/COBI/FTC/TDF (150/150/200/300 mg) on days 1-7, and after a washout, received EFV/FTC/TDF (600/200/300 mg) on days 15-28 and switched to EVG/COBI/FTC/TDF (150/150/200/300 mg) for 5 weeks (days 29-62). Pharmacokinetic assessments occurred on days 7, 28, 35, and 42; trough samples (Ctrough) were collected periodically until day 63. Safety was assessed throughout the study. RESULTS: Twenty-nine subjects completed with 3 adverse events leading to discontinuation; no grade ≥3 adverse events were reported. Post-EFV/FTC/TDF, mean EVG area under concentration (AUCtau) was 37% and 29% lower and mean Ctrough ∼3- and ∼5-fold above IC95, respectively, on days 35 and 42, and 7-8-fold above IC95 by 5 weeks. COBI AUCtau returned to normal by day 42. EVG glucuronide, GS-9200, AUCtau was higher (46% and 32% on days 35 and 42, respectively) postswitch. CYP2B6 poor metabolizers displayed higher EFV AUCtau and Cmax (125% and 91%, respectively) versus non-poor metabolizers, and lower EVG and COBI exposures. EFV Ctrough was >IC90 (10 ng/mL) in all subjects postswitch. FTC and tenofovir (TFV) exposures were unaffected. CONCLUSIONS: After EFV/FTC/TDF to EVG/COBI/FTC/TDF switch, EVG and/or EFV exposures were in an active range. These findings support further evaluation of switching regimens in HIV-1 patients.

A 68-year old male presenting with rhabdomyolysis-associated acute kidney injury following concomitant use of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate and pravastatin/fenofibrate: a case report.

INTRODUCTION: We present what we believe to be the first case in the literature of rhabdomyolysis-induced renal failure caused by a probable drug interaction between elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF) and pravastatin/fenofibrate. CASE PRESENTATION: A 68-year old Caucasian man presented with progressive pain in both legs two weeks after commencing treatment with EVG/COBI/FTC/TDF. He was found to have biochemical evidence of rhabdomyolysis and acute renal failure. CONCLUSION: We emphasize the need for post marketing surveillance of adverse effects of new products. Pharmacokinetic studies are necessary to investigate the levels of pravastatin in patients taking COBI and fenofibrate with and without other comorbidities. Meanwhile, we suggest that creatine kinase levels should be monitored and patients advised to report myalgias when using concomitant EVG/COBI/FTC/TDF and pravastatin/fenofibrate. This case serves as an important reminder to use estimated glomerular filtration rates rather than serum creatinine levels when choosing new medications. If potentially nephrotoxic combinations are started in patients with borderline estimated glomerular filtration rates, it may be prudent to check these filtration rates more frequently than usual. In patients with reduced estimated glomerular filtration rates, potentially nephrotoxic combinations should be avoided wherever possible.

Patient-Reported Symptoms over 48 Weeks in a Randomized, Open-Label, Phase 3b Non-inferiority Trial of Adults with HIV Switching to Coformulated Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir DF Versus Continuation of Ritonavir-Boosted Protease Inhibitor with Emtricitabine and Tenofovir DF.

BACKGROUND: Coformulated elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF; Stribild(®)) is a recommended integrase inhibitor-based regimen in treatment guidelines from the US Department of Health and Human Services and the British HIV Association. The purpose of this analysis was to determine the change in patient-reported symptoms over time among HIV-infected adults who switch to Stribild(®) versus those continuing on a protease inhibitor (PI) with FTC/TDF. METHODS: A secondary analysis was conducted on the STRATEGY-PI study (GS-US-236-0115, ClinicalTrials.gov NCT01475838), a randomized, open-label, phase 3b trial of HIV-infected adults taking a PI with FTC/TDF who were randomly assigned (2:1) either to Stribild(®) (switch) or continuation of their existing regimen (no-switch). Logistic regressions and longitudinal modeling were conducted to evaluate the relationship of treatment with bothersome symptoms. RESULTS: At week 4 as compared with baseline, the switch group experienced a statistically significantly lower prevalence in five symptoms (diarrhea/loose bowels, bloating/pain/gas in stomach, pain/numbness/tingling in hands/feet, nervous/anxious, and trouble remembering). The lower prevalence of diarrhea/loose bowels, bloating/pain/gas in stomach, and pain/numbness/tingling in hands/feet observed at week 4 was maintained over time. While there were no significant differences between groups in the prevalence of sad/down/depressed and problems with sex at week 4 or week 48, longitudinal models indicated the switch group had a statistically significantly decreased prevalence in both symptoms from week 4 to week 48. As compared with the no-switch group, higher levels of satisfaction with treatment were experienced by patients in the switch group at the first follow-up visit and at week 24. CONCLUSIONS: In this study sample, a switch from a ritonavir-boosted PI, FTC, and TDF regimen to coformulated EVG/COBI/FTC/TDF was associated with more treatment satisfaction and a reduction in the prevalence of patient-reported diarrhea/loose bowel symptoms, which was maintained over the 48-week study period.

Pharmacokinetic and bioequivalence evaluation of single-tablet and separate-tablet regimens for once-daily cobicistat-boosted elvitegravir in healthy Japanese male subjects: A randomized, two-way crossover study.

This randomized, two-way crossover study evaluated the bioavailability of elvitegravir administered as the new individual tablet containing 150 mg and a cobicistat 150 mg tablet, concomitantly with a fixed-dose combination tablet containing 200 mg of emtricitabine and 300 mg of tenofovir disoproxil fumarate (EVG + COBI + FTC/TDF), in comparison with a single-tablet regimen containing the same dose of each component (EVG/COBI/FTC/TDF). Twenty-four healthy Japanese male subjects received the two different elvitegravir treatments, the separate-tablet or single-tablet regimen, once-daily for 10 days in each. The pharmacokinetic parameters (Cmax , AUCtau , and Ctau ) of elvitegravir were investigated at Day 10 after each treatment, together with safety and tolerability. Relative to EVG/COBI/FTC/TDF, the geometric least-squares mean ratios (GMR) and 90% confidence intervals (CIs) for elvitegravir Cmax and AUCtau were within the boundary of 0.8-1.25, while the upper limit of the 90% CI of GMR for Ctau was narrowly below the lack of bioequivalence boundary (0.79). No deaths, serious AEs, or drug-related AEs occurred. In conclusion, Cmax and AUCtau of elvitegravir met the strict definition of bioequivalence, indicating that the two regimens were essentially bioequivalent. Treatment with both regimens for 10 days appeared to be safe and well tolerated.