Allergies to antibiotics among US women with uncomplicated urinary tract infection.

Uncomplicated urinary tract infections (uUTI) are generally treated empirically with antibiotics. However, antibiotic allergies limit the available oral treatment options for some patients. We assessed the proportion of self-reported antibiotic allergies among US women with uUTI. We performed a cross-sectional survey of US women (≥18 years) with a self-reported uUTI in the previous 60 days and an oral antibiotic prescription. Participants completed an online questionnaire about their most recent uUTI episode. Descriptive self-reported allergy data were stratified into subgroups by whether the participant had recurrent UTI (≥2 uUTIs in the past 6 months or ≥3 uUTIs in past 12 months, including the index episode), the number of different antibiotics given for the index episode (1, 2, ≥3), and whether the treatment was clinically aligned according to Infectious Diseases Society of America uUTI guidelines. Overall, 375 participants completed the questionnaire. The most commonly prescribed antibiotics were trimethoprim-sulfamethoxazole (SXT; 38.7%), ciprofloxacin (22.7%), and nitrofurantoin (18.9%). Most participants (62.7%) received only 1 antibiotic for their uUTI, and most (56.5%) were classified as having a non-recurrent uUTI. No antibiotic allergies were reported for most participants (69.3%), with 24.0% reporting 1 antibiotic allergy and 6.7% reporting ≥2 antibiotic allergies. Allergies to ≥2 antibiotic types were more common among participants classified as having recurrent uUTI, or who used multiple antibiotics to treat their uUTI. The most common allergy was to SXT (15.7%), followed by amoxicillin-clavulanate (8.3%) and ciprofloxacin (5.3%). Similar allergy trends were seen across subgroups, except higher rates of ciprofloxacin allergy were seen in participants given multiple antibiotics. Antibiotic allergies were relatively frequent in this uUTI cohort and the most common allergy was to SXT, which was the most prescribed antibiotic. Allergies to antibiotics reduce the available treatment options for uUTI in some patients.

The fluoroquinolones may positively affect tendon healing after surgical repair.

OBJECTIVES: This study aimed to evaluate the biomechanical and histological effects of fluoroquinolones on surgically repaired tendon healing. MATERIALS AND METHODS: The Achilles tendons of 40 Wistar rats (mean weight: 213.5 g; range 201 to 242 g) were bilaterally surgically cut and repaired. The rats were randomly divided into four groups: the first and third groups were designated as control groups and did not receive drug therapy, whereas the second and fourth groups received 300 mg/kg ciprofloxacin for a week after the surgical procedure. The first and second groups had both tendons dissected at the end of the first week, while the third and fourth groups were dissected at the end of the third week. The left tendons were examined biomechanically, while the right tendons were examined histologically. RESULTS: Statistical analysis revealed that the mean maximum tensile forces of tendons in the first and second groups were 5.2±1.84 N (range, 2.9 to 8.5 N) and 11.1±2.65 N (range, 7.3 to 13.9 N), respectively, which was found to be statistically significant (p< 0.05). At the end of the third week, mean maximum tensile forces of the third and fourth groups were determined to be 20.7±5.0 N (range, 22.1 to 29.8 N) and 28.7±4.6 N (range, 22.1 to 36.8 N), respectively, which was also statistically significant (p< 0.05). Histologically, our results were compatible. CONCLUSION: This study demonstrated that ciprofloxacin did not exhibit the expected adverse effects on surgically repaired tendon healing in the early stages but likely contributed to healing in the short term by affecting the inflammatory phase.

An open-label, randomized, non-inferiority trial of the efficacy and safety of ciprofloxacin versus an aminoglycoside + ciprofloxacin in the treatment of bubonic plague (IMASOY): study protocol for a randomized control trial-an update to the published protocol.

This article reports an update to the protocol of the IMASOY trial, which was prospectively registered on clinicaltrials.gov (NCT04110340) in October 2019.

A phase ib clinical trial of oral ciprofloxacin and etoposide in subjects with resistant acute myeloid leukemia.

A phase 1b study was conducted to evaluate the safety and feasibility of ciprofloxacin and etoposide combination treatment in subjects with relapsed and refractory acute myeloid leukemia. Eleven subjects were enrolled in the study. Utilizing the standard '3 + 3' design, escalating ciprofloxacin doses (750 mg, 1000 mg) twice daily on D1-D10 in combination with a fixed dose (200 mg) of etoposide on D2-D8 were administered. Maximum tolerated dose was determined to be 1000 mg of ciprofloxacin in combination with 200 mg of etoposide. Serious adverse events occurred in 54.5% (n = 6) subjects and 91% (n = 10) subjects reported ≥ grade 3 toxicities. Nine subjects completed treatment, one had a dose-limiting toxicity, and one withdrew. One subject achieved complete remission with a duration of 111 days and one subject achieved morphologic leukemia-free state after cycle 1. While the combination demonstrated safety and an acceptable toxicity profile, only modest hematologic and clinical benefits were observed.This trial was registered at www.clinicaltrials.gov as #NCT02773732.

Crystalline keratopathy secondary to the use of ciprofloxacin after cataract surgery with confirmation by histopathological study: A case report and review of the literature.

OBJECTIVE: To report the case of a 75-year-old patient who presented crystalline keratopathy secondary to the use of topical ciprofloxacin with histopathological verification, after cataract surgery without complications. METHOD: Case report with clinical and photographic follow-up, as well as slides with samples of epithelium and crystalline deposits. RESULTS: Corneal deposits resolved after drug suspension, topical lubricant change, and subsequent surgical debridement. The histopathological examination reported epithelial cells and basophilic particles compatible with drug precipitates. CONCLUSIONS: Crystalline keratopathy is a condition in which crystals of various kinds are deposited in the corneal epithelium and/or in the anterior stroma. It may have an infectious, pharmacological cause or, in rarer cases, corneal dystrophies. Certain factors such as a previous epithelial defect, systemic pathology with diabetes mellitus, ocular surgery and previous dry eye can favor the deposition of ciprofloxacin leading to the formation of a keratopathy.

Safety and Pharmacokinetics of a Ciprofloxacin and Azithromycin Stent for Chronic Rhinosinusitis.

OBJECTIVES: Previously, we developed a novel double-coated sinus stent containing ciprofloxacin (inner layer) and azithromycin (outer layer) (CASS), but released drug concentrations were found to be insufficient for clinical usage. Our objectives are to improve drug release of CASS and assess safety and pharmacokinetics in rabbits. METHODS: Dip coating was used to create the CASS with 2 mg ciprofloxacin and 5 mg azithromycin. A uniformed double coating was assessed with scanning electron microscopy (SEM), and the release patterns of both drugs and lactate dehydrogenase (LDH) assay were evaluated over 14 days in vitro. Safety, tolerability, and pharmacokinetics of the CASS were tested in rabbits through insertion into the maxillary sinus and evaluated with nasal endoscopy, CT scans, histology, blood counts and chemistries, and in vivo drug release. RESULTS: SEM confirmed the uniformity of the dual coating of ciprofloxacin and azithromycin, and thickness (µm) was found to be 14.7 ± 2.4 and 28.1 ± 4.6, respectively. The inner coated ciprofloxacin showed a sustained release over 14 days (release %) when soaked in saline solution (day 7, 86.2 ± 3.4 vs. day 14,99.2 ± 5.1). In vivo analysis showed that after 12 days, 78.92 ± 7.67% of CP and 84.12 ± 0.45% of AZ were released into the sinus. There were no significant differences in body weight, white blood cell counts, and radiographic changes before and after CASS placement. No significant histological changes were observed compared to the contralateral control side. CONCLUSION: Findings suggest that the CASS is an effective method for delivering therapeutic levels of antibiotics. Further studies are needed to validate efficacy in a preclinical sinusitis model. LEVEL OF EVIDENCE: N/A Laryngoscope, 134:3953-3959, 2024.

Safety of Nebulized Ciprodex for Postoperative Management of Tracheal Resection.

OBJECTIVE: Anastomotic complications after tracheal resection/cricotracheal resection (TR/CTR), such as granulation tissue formation, can lead to severe morbidity. The off-label use of nebulized ciprofloxacin-dexamethasone (Ciprodex) for granulation tissue prophylaxis has anecdotally been used after TR/CTR, especially in pediatric patients. However, its use in the adult population, and its safety and side effect profile post-TR/CTR has not been reported. This study aims to characterize the incidence of adverse side effects associated with nebulized Ciprodex in post-TR/CTR patients. METHODS: A retrospective review of all patients who underwent TR/CTR from June 2015 to July 2023 was performed. The use of nebulized Ciprodex (1 mL ciprofloxacin-dexamethasone 0.3%-0.1% otic suspension in 4 mL normal saline) while inpatient was evaluated. Potential side effects were defined as oral thrush, ageusia, arthralgia, and allergic reaction, and were recorded for all patients. RESULTS: Seventy-three patients underwent TR/CTR from June 2015 to July 2023. Of these, 53 (72.6%) had documented Ciprodex administration during their postoperative course. One (1.9%) patient reported at least one side effect, including one instance of skin rash (1.9%) and one instance of allergic reaction (1.9%). There were no other side effects attributed to Ciprodex use. CONCLUSIONS: The incidence of side effects related to the use of nebulized Ciprodex is felt to be minimal in post-TR/CTR. Although Ciprodex may have the potential to treat granulation tissue in the airway, further studies are needed to verify its efficacy and safety. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3695-3697, 2024.

Aplastic anaemia following antibiotic use for urinary tract infection.

Aplastic anaemia is often associated with recent viral illnesses to include EBV and parvovirus along with certain medications such as anticonvulsants and sulfa containing antibiotics. We describe a case report of a female patient in her 70s who presented with pancytopenia after being treated with nitrofurantoin and ciprofloxacin for suspected urinary tract infection. She underwent an extensive workup to rule out alternative aetiologies of her pancytopenia to include a broad viral, autoimmune and malignancy evaluation which were unrevealing. Given her recent exposure to ciprofloxacin and nitrofurantoin and marrow recovery following removal of these agents, it was presumed that antibiotic exposure was the underlying cause of her aplastic anaemia.

Assessing National Trends and Perceived Safety of Off-Label Ciprofloxacin-Dexamethasone Use by Pediatric Otolaryngologists.

OBJECTIVES: Off-label use of Ciprodex® (ciprofloxacin-dexamethasone: CPD), an antibiotic-steroid combination solution, in the airway has been reported by pediatric otolaryngologists with anecdotal success. We examined national trends regarding off-label CPD use including prevalence, common indications, prescriber patterns, adverse events, and accessibility. METHODS: 15-item cross-sectional survey was distributed to American Society of Pediatric Otolaryngology members from January-April 2022. Univariate analyses were performed to compare responses for users of off-label CPD versus non-users. Ease of access was compared across geographies and practice types using multivariate logistic regressions. RESULTS: Of the 163 complete responses (26.6% response rate), 156 (95.7%) reported using off-label CPD. Most common indications for off-label CPD were tracheal granulation (87.8%, n = 137) and choanal atresia (82.1%, n = 128). Ease of access was significantly increased in the Midwest (OR:18.79, 95%CI:3.63-1.24, p = 0.001) and West (OR:29.92, 95%CI:3.55-682.00, p = 0.006). Ease of access was significantly lower at tertiary referral centers (OR:0.11, 95%CI:0.01-0.64, p = 0.041) and private practices (OR:0.04, 95%CI:0.002-0.33, p = 0.009) compared to academic free-standing children's hospitals. Two-thirds of respondents reported feeling "Very Comfortable" with the safety profile of off-label CPD; 99.4% (n = 156) felt that the benefits outweighed the risks of off-label use. Seven respondents (4.5%) reported adverse events (e.g., local allergic reaction, cushingoid symptoms) from off-label use. CONCLUSIONS: Our findings (26.6% response rate) suggest that off-label CPD is commonly used by pediatric otolaryngologists, many of whom reported feeling that the benefits of off-label CPD outweigh the risks. Our results establish a baseline for future efforts to assess the efficacy and safety of off-label CPD and to improve its accessibility. LEVEL OF EVIDENCE: V Laryngoscope, 134:2922-2930, 2024.

Multivariate guard-bands and total risk assessment on multiparameter evaluations with correlated and uncorrelated measured values

Abstract The quality, efficacy, and safety of medicines are usually verified by analytical results. Measurement uncertainty is a critical aspect for the reliability of these analytical results. The pharmacopeial compendia usually adopt a simple acceptance rule that does not consider information from measurement uncertainty. In this work, we compared decision-making using simple acceptance and decision rules with the use of guard-band for multiparameter evaluation of ofloxacin ophthalmic solution and acyclovir topical cream. Ciprofloxacin ophthalmic solution and acyclovir topical cream samples were subject to pharmacopeial tests and assays. Multivariate guard-band widths were calculated by multiplying the standard uncertainty (u) by an appropriate multivariate coverage factor (k'). The multivariate coverage factor (k') was obtained by the Monte Carlo method. According to the simple acceptance rule, all the results obtained for ciprofloxacin ophthalmic solution and acyclovir topical cream are within the specification limits. However, the risk of false conformity decisions increases for ciprofloxacin tests. Decisions made using the simple acceptance rule and decision rules with the use of guard-band may differ. The simple acceptance rule may increase the risk of false conformity decisions when the measured value is close to the regulatory specification limits and/or when the measurement uncertainty value is inappropriately high. Nevertheless, the guard-band decision rule will always reduce the risk of false conformity decisions. Therefore, using information on measurement uncertainty in conformity assessment is highly recommended to ensure the proper efficacy, safety, and quality of medicines.

Syndrome of inappropriate antidiuretic hormone secretion as an adverse reaction of ciprofloxacin: a case report and literature review.

Antidiuretic hormone (ADH) is secreted by the posterior pituitary gland. Unsuppressed release of ADH leads to hyponatremia. This condition is referred to as syndrome of inappropriate antidiuretic hormone secretion (SIADH). Hereby, a case report is presented on ciprofloxacin-induced SIADH. A 67-year-old male patient was examined in the emergency room with symptoms of lethargy, headache, lack of attention, and a generally depressed mood lasting for three days. One week prior, empirical antimicrobial therapy involving ciprofloxacin for prostatitis was initiated. Laboratory analysis showed no relevant abnormalities except for hyponatremia (Na = 129 mmol/L). Chronic hyponatremia, thyroid dysfunction, and adrenal dysfunction were ruled out. Serum osmolality was 263 mOsmol/kg, urine osmolality was 206 mOsmol/kg, and urine sodium was 39 mmol/L. Given that all criteria for SIADH were met, ciprofloxacin was discontinued, and fluid restriction was advised. Four days later, the patient's serum sodium concentrations nearly normalized (Na = 135 mmol/L), and all symptoms resolved. The Naranjo Scale yielded a score of 8, supporting the likelihood of a probable adverse reaction to ciprofloxacin. This case is presented to raise awareness among clinicians about the potential of ciprofloxacin to cause even mild hyponatremia.

The frequency of, and predisposing risk factors for, ciprofloxacin-induced neuro-psychiatric adverse drug reactions.

OBJECTIVES: Ciprofloxacin induces rare neuro-psychiatric adverse drug reactions (ADRs) that are, as yet, not possible to predict due to unknown predisposition factors. BACKGROUND: The aim of the analysis was to assess the frequency of neuro-psychiatric ADRs and to identify potential risk factors that predisposed patients to ciprofloxacin neurotoxicity. METHODS: This observational retrospective study involved the evaluation of the medical records of patients in the Nephrology department and 3rd Internal Clinic of the General University Hospital in Prague. RESULTS: The overall incidence of neurological ADRs was 3.6 %. No neurological ADRs developed in patients aged less than 70 years. The covariates that were significantly more prevalent in the patients who developed neuropsychiatric ADRs were as follows: higher age, a history of neuropsychiatric disorders and the use of anticonvulsants. The administration of drugs from other ATC groups, gender, weight, body mass index, body surface area, renal functions, level of C-reactive protein at the beginning of treatment and the total daily dose/kg did not differ significantly between the two groups. CONCLUSION: Ciprofloxacin neuropsychiatric ADRs are more frequent in older patients with a history of neurologic or psychiatric disorders. No other tested covariates were proven to predispose patients to neuropsychiatric ADRs during treatment with ciprofloxacin (Tab. 2, Ref. 20).

Neurobehavioral impairments in ciprofloxacin- treated osteoarthritic adult rats.

Background and purpose:

Ciprofloxacin (CIP) is a broad-spectrum antibiotic widely used in clinical practice to treat musculoskeletal infections. Fluoroquinolone-induced neurotoxic adverse events have been reported in a few case reports, all the preclinical studies on its neuropsychiatric side effects involved only healthy animals. This study firstly investigated the behavioral effects of CIP in an osteoarthritis rat model with joint destruction and pain, which can simulate inflammation-associated musculoskeletal pain. Furthermore, effects of CIP on regional brain-derived neurotrophic factor (BDNF) expression were examined given its major contributions to the neuromodulation and plasticity underlying behavior and cognition. 

Fourteen days after induction of chronic osteoarthritis, animals were administered vehicle, 33 mg/kg or 100 mg/kg CIP for five days intraperitoneally. Motor activity, behavioral motivation, and psychomotor learning were examined in a reward-based behavioral test (Ambitus) on Day 4 and sensorimotor gating by the prepulse inhibition test on Day 5. Thereafter, the prolonged BDNF mRNA and protein expression levels were measured in the hippocampus and the prefrontal cortex. 

CIP dose-dependently reduced both locomotion and reward-motivated exploratory activity, accompanied with impaired learning ability. In contrast, there were no significant differences in startle reflex and sensory gating among treatment groups; however, CIP treatment reduced motor activity of the animals in this test, too. These alterations were associated with reduced BDNF mRNA and protein expression levels in the hippocampus but not the prefrontal cortex. 

This study revealed the detrimental effects of CIP treatment on locomotor activity and motivation/learning ability during osteoarthritic condition, which might be due to, at least partially, deficient hippocampal BDNF expression and ensuing impairments in neural and synaptic plasticity.

FOVOCIP study: a multicenter randomized trial of fosfomycin versus ciprofloxacin for febrile neutropenia in hematologic patients-efficacy and microbiologic safety.

BACKGROUND: Multidrug-resistant Gram-negative bacterial (MRGNB) infections represent a major public health threat. Cancer patients and, among them, hematological patients are most vulnerable to these infections. Gut colonization by MRGNB is a common phenomenon occurring during hospitalization and chemotherapy exposure. In the neutropenic phase that occurs after chemotherapy, MRGNB translocation occurs increasing patient's mortality. Fluoroquinolone prophylaxis with ciprofloxacin or levofloxacin efficacy is now being questioned due to the increase of incidence in MRGNB. METHODS: A phase III randomized, controlled, clinical trial, open-label parallel-group with a 1:1 ratio, aimed to demonstrate the non-inferiority of oral fosfomycin versus oral ciprofloxacin for febrile neutropenia prevention in patients with acute leukemia (AL) or hematopoietic cell transplant (HSC) receptors. Weekly surveillance cultures are planned to detect gut colonization. Changes in fecal microbiome at the beginning and end of prophylaxis will also be analyzed. DISCUSSION: This trial will provide evidence of the efficacy of an alternative drug to ciprofloxacin for febrile neutropenia prevention in high-risk hematological patients. The battery of planned microbiological studies will allow us to evaluate prospectively the microbiological safety of both pharmacological strategies in terms of the selection of MRGNB occurring in each arm. In addition, valuable information on the way in which each drug changes the fecal microbiome of the patients throughout the treatment will be generated. TRIAL REGISTRATION: Clinical trials NCT05311254, Registered on 5 April 2022, https://clinicaltrials.gov/ct2/show/NCT05311254?term=FOVOCIP&cntry=ES&draw=2&rank=1 . PROTOCOL VERSION: 3.0, dated 20 May 2022.

Ciprofloxacin-Induced Anaphylactic Reaction Followed by Negative Provocation Test in Response to Levofloxacin: A Case Report.

Fluoroquinolones are a commonly prescribed class of antibiotics due to their broad spectrum of antimicrobial activity, favorable pharmacokinetic properties, ability to switch from parenteral to oral administration, and global availability. After beta-lactams, they are the second most common antibiotic class associated with drug allergies. The mechanism of fluoroquinolone-induced hypersensitivity reactions has not yet been fully understood, so the true incidence of hypersensitivity reactions remains unknown. Cross-reactivity between fluoroquinolones has been the subject of conflicting and limited clinical research. Due to their similar chemical structure, some argue for close cross-reactivity within the group. However, recent studies have produced contradictory results. We present the case of a young patient who had an anaphylactic reaction to ciprofloxacin but was tolerant to levofloxacin, as determined via a skin prick test followed by a drug provocation test. Our findings support the notion that there is little cross-reactivity between fluoroquinolones. Consequently, exposure to another fluoroquinolone in a hospital setting may be beneficial, particularly for patients who lack adequate antibiotic alternatives. However, additional research on this subject is required.

Three Cases of Myoclonus Secondary to Ciprofloxacin: "Ciproclonus".

OBJECTIVES: Ciprofloxacin is a fluoroquinolone that is used for bacterial infections involving different systems. In some cases, ciprofloxacin was reported to induce myoclonus. METHODS: We performed a chart review of 3 patients with myoclonus secondary to ciprofloxacin and reviewed the literature for similar cases. Written consent for publication was obtained from each patient, and their identities were concealed for ethical reasons. RESULTS: We describe 3 cases of myoclonus secondary to ciprofloxacin, 2 males and a female aged 61, 26, and 48 years, respectively. The myoclonus appeared within 3 days of ciprofloxacin intake. In all 3 cases, ciprofloxacin was prescribed for urinary tract infection. Electroencephalogram and neuroimaging studies were normal and possible causes were excluded. Thus, ciprofloxacin was believed to be the underlying cause and hence it was withdrawn. The patients had complete recovery on follow-up. CONCLUSIONS: Although ciprofloxacin is widely prescribed for different infections, only 13 cases were reported to develop myoclonus secondary to ciprofloxacin. The mean age of patients was 62 years. Fifty-four percent of cases were males. Cessation of ciprofloxacin was the most common management course. All individuals fully recovered after ciprofloxacin withdrawal. The mechanism of ciprofloxacin-induced myoclonus is probably associated with γ-aminobutyric acid and glutamate pathways.

Long-term Cardiovascular Adverse Events Induced by Fluoroquinolones: A Retrospective Case-control Study.

ABSTRACT: A correlation is already established between fluoroquinolones (FQs) use and cardiovascular events (CVEs), such as QT prolongation; however, serious events such as aortic aneurysm and valve regurgitation have also been reported with FQs. Several unstudied factors could contribute to the development of different CVEs that were not previously evaluated with FQ therapy. Therefore, we aimed to assess the incidence of different serious CVEs after completion of FQ therapy and potential associating factors. This was a retrospective case-control study of inpatients who received ciprofloxacin, levofloxacin, or moxifloxacin for ≥3 days. Patients' echocardiograms were evaluated for the development of aortic or valvular disease or worsening of an existing condition after completion of therapy. Of 373 included patients, 83 developed new valvular disease or worsening of an existing disease, where tricuspid valve regurgitation was the most common CVE (50/83; 60.2%), followed by mitral valve diseases (48/83; 57.8%). Aortic valve regurgitation occurred more commonly with moxifloxacin compared with ciprofloxacin and levofloxacin (17.8% vs. 6.7% and 10.7%, respectively; P = 0.01). Median time to CVE detection ranged 93-166 days for all FQs. The receipt of moxifloxacin and elevated baseline QT interval were associated with an increased CVEs risk (adjusted odds ratio 3.26; 95% confidence interval, 1.31-8.11 and adjusted odds ratio 1.02; 95% confidence interval, 1.00-1.04, respectively). Other factors did not show such association. The lack of association of different factors with the occurrence of CVEs indicates that all patients receiving FQ therapy, especially moxifloxacin, should be monitored during the first-year after therapy. Alternatively, other antibiotics with a better safety profile may be considered.

Drug-Induced Liver Injury with Commonly Used Antibiotics in the All of Us Research Program.

Antibiotics are a known cause of idiosyncratic drug-induced liver injury (DILI). According to the Centers for Disease Control and Prevention, the five most commonly prescribed antibiotics in the United States are azithromycin, ciprofloxacin, cephalexin, amoxicillin, and amoxicillin-clavulanate. We quantified the frequency of acute DILI for these common antibiotics in the All of Us Research Program, one of the largest electronic health record (EHR)-linked research cohorts in the United States. Retrospective analyses were conducted applying a standardized phenotyping algorithm to de-identified clinical data available in the All of Us database for 318,598 study participants. Between February 1984 and December 2022, more than 30% of All of Us participants (n = 119,812 individuals) had been exposed to at least 1 of our 5 study drugs. Initial screening identified 591 potential case patients that met our preselected laboratory-based phenotyping criteria. Because DILI is a diagnosis of exclusion, we then used phenome scanning to narrow the case counts by (i) scanning all EHRs to identify all alternative diagnostic explanations for the laboratory abnormalities, and (ii) leveraging International Classification of Disease 9th revision (ICD)-9 and ICD 10th revision (ICD)-10 codes as exclusion criteria to eliminate misclassification. Our final case counts were 30 DILI cases with amoxicillin-clavulanate, 24 cases with azithromycin, 24 cases with ciprofloxacin, 22 cases with amoxicillin alone, and < 20 cases with cephalexin. These findings demonstrate that data from EHR-linked research cohorts can be efficiently mined to identify DILI cases related to the use of common antibiotics.