Possible Interaction: Ribavirin and Vitamin D

“Recent clinical trials have shown that vitamin D supplements significantly enhance the efficacy of interferon plus ribavirin therapy through sustained virological response.”

“Therefore, the cumulative proportion of patients with RBV dose reduction was significantly higher and total dose of RBV was significantly lower in patients with CC genotype compared to CA/AA genotypes.”

“The RBV dose reduction was higher in CC than non-CC group.”

“Chronic HCV–infected patients tend to have vitamin D deficiency, suggesting that vitamin D supplementation may enhance the efficacy of treatment with pegylated interferon (PEG‐IFN) and ribavirin (RBV).”

“Reduction of the amount of the planned RBV dose was significantly higher for CC patients than non-CC patients during the first 12 wk (18% ± 12.1% vs 8.5% ± 10.2%, P = 0.021).”

“The percentage of CC patients with RBV dose reduction was significantly greater than that of non-CC patients (77.4% vs 44.4%, P = 0.044).”

“ RBV dose reduction was more … patients with the CC genotype than in those with the CA/AA genotype (odds ratio [OR] = 11.81; 95% confidence interval [CI] = 1.45 …; P = 0.0039), as was erythropoietin therapy (OR = 8.28; 95% CI = 1.04 to 371.12; P = 0.0057).”

“Cumulative reduction of ribavirin was significantly more frequent in genotype CC patients than non‐CC patients (odds ratio 1.928, P = 8.6 × 10−8).”

“ RBV dose during the first 12 … was smaller in patients with CC than CA/AA genotypes (52 ± 14% vs. 65 ± 21% of the target dose, P = 0.039), but the total RBV dose was no different between them (49 ± 17% and 54 ± 18% of the target, P = 0.531).”

“BACKGROUND AND AIMS Previous studies suggest that low serum 25-hydroxyvitamin D [25(OH) D] levels are associated with reduced responsiveness to interferon and ribavirin therapy.”