{"doi":"10.1093/jac/dkab057","title":"Levofloxacin pharmacokinetics in saliva as measured by a mobile microvolume UV spectrophotometer among people treated for rifampicin-resistant TB in Tanzania","abstract":"BACKGROUND: Early detection and correction of low fluoroquinolone exposure may improve treatment of MDR-TB. OBJECTIVES: To explore a recently developed portable, battery-powered, UV spectrophotometer for measuring levofloxacin in saliva of people treated for MDR-TB. METHODS: Patients treated with levofloxacin as part of a regimen for MDR-TB in Northern Tanzania had serum and saliva collected concurrently at 1 and 4 h after 2 weeks of observed levofloxacin administration. Saliva levofloxacin concentrations were quantified in the field via spectrophotometry, while serum was analysed at a regional laboratory using HPLC. A Bayesian population pharmacokinetics model was used to estimate the area under the concentration-time curve (AUC0-24). Subtarget exposures of levofloxacin were defined by serum AUC0-24 <80 mg·h/L. The study was registered at Clinicaltrials.gov with clinical trial identifier NCT04124055. RESULTS: Among 45 patients, 11 (25.6%) were women and 16 (37.2%) were living with HIV. Median AUC0-24 in serum was 140 (IQR = 102.4-179.09) mg·h/L and median AUC0-24 in saliva was 97.10 (IQR = 74.80-121.10) mg·h/L. A positive linear correlation was observed with serum and saliva AUC0-24, and a receiver operating characteristic curve constructed to detect serum AUC0-24 below 80 mg·h/L demonstrated excellent prediction [AUC 0.80 (95% CI = 0.62-0.94)]. Utilizing a saliva AUC0-24 cut-off of 91.6 mg·h/L, the assay was 88.9% sensitive and 69.4% specific in detecting subtarget serum AUC0-24 values, including identifying eight of nine patients below target. CONCLUSIONS: Portable UV spectrophotometry as a point-of-care screen for subtarget levofloxacin exposure was feasible. Use for triage to other investigation or personalized dosing strategy should be tested in a randomized study.","journal":"Journal of Antimicrobial Chemotherapy","year":2021,"id":169122,"datarank":0.7209372754373302,"base_score":3.4011973816621555,"endowment":3.4011973816621555,"self_citation_contribution":0.5101796072493234,"citation_network_contribution":0.21075766818800684,"self_endowment_contribution":0.5101796072493234,"citer_contribution":0.21075766818800684,"corpus_percentile":null,"corpus_rank":null,"citation_count":29,"citer_count":13,"citers_with_citation_signal":8,"citers_with_endowment":8,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9569,"is_data_producer":true,"deposit_databanks":{"ClinicalTrials.gov":["NCT04124055"]},"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":699408,"name":"Happiness Mvungi","orcid":"0000-0001-6527-4887","position":1,"is_corresponding":false},{"id":699409,"name":"Margaretha Sariko","orcid":"0000-0001-6264-773X","position":2,"is_corresponding":false},{"id":365913,"name":"Prakruti Rao","orcid":null,"position":3,"is_corresponding":false},{"id":699410,"name":"Peter M. Mbelele","orcid":"0000-0002-2693-187X","position":4,"is_corresponding":false},{"id":699411,"name":"Erwin M. Jongedijk","orcid":"0000-0002-4786-8961","position":5,"is_corresponding":false},{"id":700050,"name":"C. Winkel","orcid":null,"position":6,"is_corresponding":false},{"id":699412,"name":"Daan J. Touw","orcid":"0000-0002-1429-4789","position":7,"is_corresponding":false},{"id":700051,"name":"Suzanne Stroup","orcid":null,"position":8,"is_corresponding":false},{"id":259178,"name":"Jan‐Willem C. Alffenaar","orcid":"0000-0001-6703-0288","position":9,"is_corresponding":false},{"id":365122,"name":"Stellah Mpagama","orcid":"0000-0002-0660-6930","position":10,"is_corresponding":false},{"id":365125,"name":"Scott K. Heysell","orcid":"0000-0002-2040-0293","position":11,"is_corresponding":false},{"id":700049,"name":"Sagal Mohamed","orcid":null,"position":0,"is_corresponding":true}],"reference_count":34,"raw_metadata":null,"created_at":"2026-07-18T23:46:11.334362Z","pmid":"33675664","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}