Rapid Methadone Induction in a General Hospital Setting: A Retrospective, Observational Analysis.

BACKGROUND: Outpatient methadone guidelines recommend starting at a low dose and titrating slowly. As fentanyl prevalence and opioid-related mortality increases, there is a need for individuals to rapidly achieve a therapeutic methadone dose. Hospitalization offers a monitored setting for methadone initiation, however dosing practices and safety are not well described. METHODS: Retrospective, observational analysis of hospitalized patients with opioid use disorder seen by an inpatient addiction consult team in an academic medical center who were newly initiated on methadone between 2016 and 2022. We calculated initial daily dose, maximum daily dose, timing interval of dose escalation, whether patients were connected to an opioid treatment program (OTP) prior to discharge, whether adverse effects or safety events occurred during the hospitalization, and whether such events were definitely or probably related versus possibly related or unrelated to methadone. RESULTS: One hundred twelve patients were included. The mean initial daily methadone dose administered was 32 mg (range: 10-90 mg). The mean maximum dose reached was 76.8 mg (range 30-165 mg). The mean number of days from initial to peak dose was 5.6 days (range 1-19 days). Overall, 30% of patients experienced a safety event, most commonly sedation. Only 4 safety events were deemed probably or definitely related to methadone. In regression analyses, there was no significant difference between starting doses among patients with or without sedation but there was a relationship between last dose and the likelihood of any possibly related event, with those ending at a dose of 100 mg or higher having a higher likelihood event, compared to those ending at lower doses (47.8% vs 12.4%, P < .001). Seventy-six percent were connected to OTP before discharge. CONCLUSION: Among hospitalized patients initiating methadone, rapid dose titration was infrequently associated with related safety events and most were connected to community-based methadone treatment before discharge.

Dietary phosphate restriction attenuates polycystic kidney disease in mice.

Studies in rodents with reduced nephron mass have suggested a strong positive correlation between dietary phosphate consumption and CKD progression. Prior work by our group demonstrated that dietary phosphate restriction can prevent tubular injury and microcyst formation in rodents with glomerulonephritis. Tubular injury and cystic dilation of tubules are key contributors to kidney function decline in polycystic kidney disease (PKD). Here, we determined whether dietary phosphate restriction slows renal cyst growth and fibrosis in a mouse model of PKD. Pcy/pcy mice received a normal phosphate (0.54%) or a phosphate-restricted (0.02%) diet (n = 10/group) from 7 to 20 wk of age. All of the other major dietary constituents, including protein source and content, were comparable between the two diets. At 20 wk, body weight, kidney weight-to-body weight ratio (KW/BW), cystic area, cyst number, and kidney fibrosis were quantified. Pcy/pcy mice fed a phosphate-restricted diet had lower serum phosphate, fibroblast growth factor 23, and parathyroid hormone levels, along with elevated serum calcium levels and increased kidney Klotho gene expression compared with mice that consumed the control diet. Dietary phosphate restriction resulted in a 25% lower KW/BW ratio and reduced the cyst number, cystic index, and gene expression for the tubular injury markers neutrophil gelatinase-associated lipocalin and interleukin-18. Mice fed the phosphate-restricted diet exhibited lower kidney expression for pathways involved in collagen deposition and myofibroblast activation (collagen type I-α1, phosphorylated SMAD3, and α-smooth muscle actin); however, histological differences in kidney fibrosis were not appreciated. Dietary phosphate restriction slows cystogenesis and inhibits the activation of key pathways in the generation of kidney fibrosis in PKD mice.