National Cohort Study of Homebound Persons Living With Dementia: Antibiotic Prescribing Trends and Opportunities for Antibiotic Stewardship.

Background: Over 7 million older Americans are homebound. Managing infections in homebound persons presents unique challenges that are magnified among persons living with dementia (PLWD). This work sought to characterize antibiotic use in a national cohort of PLWD who received home-based primary care (HBPC) through the Veterans Health Administration. Methods: Administrative data identified veterans aged ≥65 years with ≥2 physician home visits in a year between 2014 and 2018 and a dementia diagnosis 3 years before through 1 year after their initial HBPC visit. Antibiotics prescribed orally, intravenously, intramuscularly, or by enema within 3 days of an HBPC visit were assessed from the initial HBPC visit to death or December 31, 2018. Prescription fills and days of therapy (DOT) per 1000 days of home care (DOHC) were calculated. Results: Among 39 861 PLWD, the median age (interquartile range [IQR]) was 85 (78-90) years, and 15.0% were Black. Overall, 16 956 (42.5%) PLWD received 45 122 prescription fills. The antibiotic use rate was 20.7 DOT per 1000 DOHC. Telephone visits and advanced practice provider visits were associated with 30.9% and 42.0% of fills, respectively. Sixty-seven percent of fills were associated with diagnoses for conditions where antibiotics are not indicated. Quinolones were the most prescribed class (24.3% of fills). The overall median length of therapy (IQR) was 7 (7-10) days. Antibiotic use rates varied across regions. Within regions, the median annual antibiotic use rate decreased from 2014 to 2018. Conclusions: Antibiotic prescriptions were prevalent in HBPC. The scope, appropriateness, and harms of antibiotic use in homebound PLWD need further investigation.

Prolonged Retrobulbar Local Anesthesia of the Cornea Does Not Cause Keratopathy in Mice.

Purpose: Prolonged local anesthesia (PLA) of the cornea is currently assumed to cause neurotrophic keratitis and is strongly discouraged. We investigate whether PLA of the cornea per se causes neurotrophic keratitis. Methods: PLA of the cornea was induced in 12 female albino BALB/c mice by retrobulbar injection of a polymeric prodrug (PGS-TTX) where the site 1 sodium channel blocker tetrodotoxin (TTX) was slowly released from the polymer polyglycerol sebacate. The duration and depth of corneal anesthesia was monitored by the Cochet-Bonnet esthesiometer. Corneal injury from PLA was assessed by slit lamp examination with 2% sodium fluorescein dye, histology, corneal nerve density by immunohistochemistry with anti-ß III tubulin antibody and confocal microscopy, and corneal neurotrophin levels (substance P and neurokinin A) by an enzyme-linked immunosorbent assay. PLA was also induced by topical amitriptyline (80 mM), used as a positive control for local anesthetic-induced corneal injury. Frequent ocular lubrication was provided. Results: Retrobulbar PGS-TTX resulted in complete corneal anesthesia lasting 50.1 ± 3.6 hours and mean time to complete resolution of block of 55.1 ± 3.6 hours with no keratopathy provided lubrication was provided. Topical 80 mM amitriptyline induced complete corneal anesthesia for 24 hours and developed keratopathy. There was no difference in the histology, levels of corneal neurotrophins, and corneal nerve density between the retrobulbar PGS-TTX group and normal cornea. Conclusions: In the absence of topical toxicity or corneal exposure, PLA of the cornea per se does not cause keratitis. Translational Relevance: PLA of the cornea could be highly beneficial in acute and chronic painful corneal conditions.

Light-triggered release of conventional local anesthetics from a macromolecular prodrug for on-demand local anesthesia.

An on-demand anesthetic that would only take effect when needed and where the intensity of anesthesia could be easily adjustable according to patients' needs would be highly desirable. Here, we design and synthesize a macromolecular prodrug (P407-CM-T) in which the local anesthetic tetracaine (T) is attached to the polymer poloxamer 407 (P407) via a photo-cleavable coumarin linkage (CM). P407-CM-T solution is an injectable liquid at room temperature and gels near body temperature. The macromolecular prodrug has no anesthetic effect itself unless irradiated with a low-power blue light emitting diode (LED), resulting in local anesthesia. By adjusting the intensity and duration of irradiation, the anesthetic effect can be modulated. Local anesthesia can be repeatedly triggered.

Prolonged Duration Local Anesthesia by Combined Delivery of Capsaicin- and Tetrodotoxin-Loaded Liposomes.

BACKGROUND: Capsaicin, the active component of chili peppers, can produce sensory-selective peripheral nerve blockade. Coadministration of capsaicin and tetrodotoxin, a site-1 sodium channel blocker, can achieve a synergistic effect on duration of nerve blocks. However, capsaicin can be neurotoxic, and tetrodotoxin can cause systemic toxicity. We evaluated whether codelivery of capsaicin and tetrodotoxin liposomes can achieve prolonged local anesthesia without local or systemic toxicity. METHODS: Capsaicin- and tetrodotoxin-loaded liposomes were developed. Male Sprague-Dawley rats were injected at the sciatic nerve with free capsaicin, capsaicin liposomes, free tetrodotoxin, tetrodotoxin liposomes, and blank liposomes, singly or in combination. Sensory and motor nerve blocks were assessed by a modified hotplate test and a weight-bearing test, respectively. Local toxicity was assessed by histologic scoring of tissues at the injection sites and transmission electron microscopic examination of the sciatic nerves. Systemic toxicity was assessed by rates of contralateral nerve deficits and/or mortality. RESULTS: The combination of capsaicin liposomes and tetrodotoxin liposomes achieved a mean duration of sensory block of 18.2 hours (3.8 hours) [mean (SD)], far longer than that from capsaicin liposomes [0.4 hours (0.5 hours)] (P < .001) or tetrodotoxin liposomes [0.4 hours (0.7 hours)] (P < .001) given separately with or without the second drug in free solution. This combination caused minimal myotoxicity and muscle inflammation, and there were no changes in the percentage or diameter of unmyelinated axons. There was no systemic toxicity. CONCLUSIONS: The combination of encapsulated tetrodotoxin and capsaicin achieved marked prolongation of nerve block. This combination did not cause detectable local or systemic toxicity. Capsaicin may be useful for its synergistic effects on other formulations even when used in very small, safe quantities.

Polymer-tetrodotoxin conjugates to induce prolonged duration local anesthesia with minimal toxicity.

There is clinical and scientific interest in developing local anesthetics with prolonged durations of effect from single injections. The need for such is highlighted by the current opioid epidemic. Site 1 sodium channel blockers such as tetrodotoxin (TTX) are extremely potent, and can provide very long nerve blocks but the duration is limited by the associated systemic toxicity. Here we report a system where slow release of TTX conjugated to a biocompatible and biodegradable polymer, poly(triol dicarboxylic acid)-co-poly(ethylene glycol) (TDP), is achieved by hydrolysis of ester linkages. Nerve block by the released TTX is enhanced by administration in a carrier with chemical permeation enhancer (CPE) properties. TTX release can be adjusted by tuning the hydrophilicity of the TDP polymer backbone. In vivo, 1.0-80.0 µg of TTX released from these polymers produced a range of durations of nerve block, from several hours to 3 days, with minimal systemic or local toxicity.

Intravenous treatment of choroidal neovascularization by photo-targeted nanoparticles.

Choroidal neovascularization (CNV) is the major cause of vision loss in wet age-related macular degeneration (AMD). Current therapies require repeated intravitreal injections, which are painful and can cause infection, bleeding, and retinal detachment. Here we develop nanoparticles (NP-[CPP]) that can be administered intravenously and allow local drug delivery to the diseased choroid via light-triggered targeting. NP-[CPP] is formed by PEG-PLA chains modified with a cell penetrating peptide (CPP). Attachment of a DEACM photocleavable group to the CPP inhibits cellular uptake of NP-[CPP]. Irradiation with blue light cleaves DEACM from the CPP, allowing the CPP to migrate from the NP core to the surface, rendering it active. In mice with laser-induced CNV, intravenous injection of NP-[CPP] coupled to irradiation of the eye allows NP accumulation in the neovascular lesions. When loaded with doxorubicin, irradiated NP-[CPP] significantly reduces neovascular lesion size. We propose a strategy for non-invasive treatment of CNV and enhanced drug accumulation specifically in diseased areas of the eye.

Effect of Cranberry Capsules on Bacteriuria Plus Pyuria Among Older Women in Nursing Homes: A Randomized Clinical Trial.

Importance: Bacteriuria plus pyuria is highly prevalent among older women living in nursing homes. Cranberry capsules are an understudied, nonantimicrobial prevention strategy used in this population. Objective: To test the effect of 2 oral cranberry capsules once a day on presence of bacteriuria plus pyuria among women residing in nursing homes. Design, Setting, and Participants: Double-blind, randomized, placebo-controlled efficacy trial with stratification by nursing home and involving 185 English-speaking women aged 65 years or older, with or without bacteriuria plus pyuria at baseline, residing in 21 nursing homes located within 50 miles (80 km) of New Haven, Connecticut (August 24, 2012-October 26, 2015). Interventions: Two oral cranberry capsules, each capsule containing 36 mg of the active ingredient proanthocyanidin (ie, 72 mg total, equivalent to 20 ounces of cranberry juice) vs placebo administered once a day in 92 treatment and 93 control group participants. Main Outcomes and Measures: Presence of bacteriuria (ie, at least 105 colony-forming units [CFUs] per milliliter of 1 or 2 microorganisms in urine culture) plus pyuria (ie, any number of white blood cells on urinalysis) assessed every 2 months over the 1-year study surveillance; any positive finding was considered to meet the primary outcome. Secondary outcomes were symptomatic urinary tract infection (UTI), all-cause death, all-cause hospitalization, all multidrug antibiotic-resistant organisms, antibiotics administered for suspected UTI, and total antimicrobial administration. Results: Of the 185 randomized study participants (mean age, 86.4 years [SD, 8.2], 90.3% white, 31.4% with bacteriuria plus pyuria at baseline), 147 completed the study. Overall adherence was 80.1%. Unadjusted results showed the presence of bacteriuria plus pyuria in 25.5% (95% CI, 18.6%-33.9%) of the treatment group and in 29.5% (95% CI, 22.2%-37.9%) of the control group. The adjusted generalized estimating equations model that accounted for missing data and covariates showed no significant difference in the presence of bacteriuria plus pyuria between the treatment group vs the control group (29.1% vs 29.0%; OR, 1.01; 95% CI, 0.61-1.66; P = .98). There were no significant differences in number of symptomatic UTIs (10 episodes in the treatment group vs 12 in the control group), rates of death (17 vs 16 deaths; 20.4 vs 19.1 deaths/100 person-years; rate ratio [RR], 1.07; 95% CI, 0.54-2.12), hospitalization (33 vs 50 admissions; 39.7 vs 59.6 hospitalizations/100 person-years; RR, 0.67; 95% CI, 0.32-1.40), bacteriuria associated with multidrug-resistant gram-negative bacilli (9 vs 24 episodes; 10.8 vs 28.6 episodes/100 person-years; RR, 0.38; 95% CI, 0.10-1.46), antibiotics administered for suspected UTIs (692 vs 909 antibiotic days; 8.3 vs 10.8 antibiotic days/person-year; RR, 0.77; 95% CI, 0.44-1.33), or total antimicrobial utilization (1415 vs 1883 antimicrobial days; 17.0 vs 22.4 antimicrobial days/person-year; RR, 0.76; 95% CI, 0.46-1.25). Conclusions and Relevance: Among older women residing in nursing homes, administration of cranberry capsules vs placebo resulted in no significant difference in presence of bacteriuria plus pyuria over 1 year. Trial Registration: clinicaltrials.gov Identifier: NCT01691430.

Diagnosis and management of urinary tract infection in older adults.

Urinary tract infection (UTI) is a commonly diagnosed infection in older adults. Despite consensus guidelines developed to assist providers in diagnosing UTI, distinguishing symptomatic UTI from asymptomatic bacteriuria (ASB) in older adults is problematic, as many older adults do not present with localized genitourinary symptoms. This article summarizes the recent literature and guidelines on the diagnosis and management of UTI and ASB in older adults.