{'fraction_non_alphanumeric': 0.04479840716774515, 'fraction_numerical': 0.055251368840219015, 'mean_word_length': 5.109422492401216, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Retrospective, Cohort‐Based Survey of Patients Using Twice‐Daily Indinavir + Ritonavir Combinations: Pharmacokinetics, Safety, and Efficacy

Objective: To describe the pharmacokinetics, safety, and efficacy of twice‐daily indinavir + ritonavir regimens Design: A cohort‐based survey of HIV‐infected patients who either used indinavir 800 mg + ritonavir 100 mg twice daily or indinavir 400 mg + ritonavir 400 mg twice daily. Methods: Data were extracted from a database of samples sent to our laboratory for measurement of indinavir + ritonavir plasma concentrations. Patient characteristics, safety, and efficacy measurements were collected by retrospective chart review. Results: 100 Patients using 800‐mg indinavir + 100‐mg ritonavir twice daily and 32 patients using 400‐mg indinavir + 400‐mg ritonavir twice daily were eligible. Median peak and trough concentrations of indinavir were 6.8 and 0.77 mg/L in the 800/100 group and 2.6 and 0.45 mg/L in the 400/400 group. The most frequently found side effects were nausea and vomiting, which occurred in 22.1% and 34.9% of the patients in the 800/100 and the 400/400 groups, respectively. Viral load data were analyzed for patients who switched from 800‐mg indinavir three times daily to one of the indinavir + ritonavir twice daily regimens. At the time of switch 63% (800/100 group) and 60% (400/400 group) had an undetectable viral load and this increased to 77% and 70%, respectively, during follow‐up. Patients who switched to the 400/400 group discontinued treatment more frequently than patients who switched to the 800/100 group (70% vs. 26%, p = .008). Conclusions: Indinavir + ritonavir regimens show improved pharmacokinetic properties, allowing twice‐daily dosing with food. Clinical data suggest that safety and efficacy is at least as good as with indinavir three‐times‐daily regimens without ritonavir. Prospective, comparative trials are needed to properly assess the role in HIV therapy of these twice‐daily indinavir + ritonavir regimens.