Safety and Tolerability of High Dose Atazanavir–Ritonavir and Lopinavir–Ritonavir in Pregnant Women Living with Human Immunodeficiency Virus

BACKGROUND: During late pregnancy, the standard dose of atazanavir boosted with ritonavir (ATV/r) is increased to 400/100mg once daily and the standard dose of lopinavir boosted with ritonavir (LPV/r) is increased to 600/150mg twice daily due to physiologic and metabolic changes. These higher doses may impact the tolerability of antiretroviral therapy (ART). The objective of this study was to describe adverse events (AE) in pregnant women living with HIV receiving ATV/r vs. LPV/r. METHODS: This retrospective cohort included pregnant women receiving high dose ATV/r or LPV/r-based ART from Sept 2007-Dec 2014. AEs were assessed by laboratory parameters and medical chart documentation from the first visit during pregnancy through delivery. AE severity was based on the Division of AIDS Table for Grading the Severity of Adult AEs. The primary endpoint was a between-group comparison of documented AEs. Data are presented as n, percent, or median (interquartile range, IQR). RESULTS: A total of 99 patients were included (n = 41 ATV/r, n = 58 LPV/r). Patients were 29 years old (IQR 24–34), African American (43%), and living with HIV for 5 years (IQR 1–9). Baseline demographics were similar between groups. Overall, 94.8% of the LPV/r arm experienced at least one AE (n = 58), and 70.7% (n = 29) experienced an AE in the ATV/r arm (P < 0.01). There were 3.8 AEs/patient (n = 218) in the LPV/r arm and 2.6 AEs/patient (n = 106) in the ATV/r arm. Nausea/vomiting was the most common AE in each arm (n = 44 LPV/r and n = 19 ATV/r). Most AEs were grade 1 in (LPV/r: 194 (89%) and ATV/r: 81 (76%); P < 0.01); however, there were a higher number of grade 3 (n = 7 ATV/r, n = 5 LPV/r) and grade 4 (n = 2 ATV/r, n = 0 LPV/r) AEs seen in the ATV/r arm. LPV/r was discontinued in 3 patients and ATV/r was discontinued in 2 patients. There was no difference in percentage of patients with an undetectable viral load at any monitoring point including the week before end of term (n = 29/32, 90.6% ATV/r; n = 33/42, 78.6% LPV/r; P > 0.05 for all). CONCLUSION: Patients treated with ATV/r experienced lower overall rates of AEs compared with LPV/r. The majority of AEs were grade 1 and few patients needed to discontinue ATV/r or LPV/r due to AEs. DISCLOSURES: All authors: No reported disclosures.