{"id":21396,"date":"2013-05-29T16:06:39","date_gmt":"2013-05-29T16:06:39","guid":{"rendered":"http:\/\/i-base.info\/htb\/?p=21396"},"modified":"2013-05-29T16:06:39","modified_gmt":"2013-05-29T16:06:39","slug":"bilirubin-as-a-surrogate-marker-for-atazanavir-in-children","status":"publish","type":"post","link":"https:\/\/i-base.info\/htb\/21396","title":{"rendered":"Bilirubin as a surrogate marker for atazanavir in children"},"content":{"rendered":"<p><strong>Polly Clayden, HIV i-Base<\/strong><\/p>\n<p><strong>Findings for a study looking at paediatric atazanavir dosing and plasma bilirubin as a possible surrogate for atazanavir therapeutic drug monitoring (TDM) were presented at the 14th International Workshop on Clinical Pharmacology.<\/strong><\/p>\n<p>Although atazanavir dose is not predictive of Cmin, bilirubin might be a surrogate marker for atazanavir Cmin in this population.<\/p>\n<p>TDM data of atazananvir from children and adolescents &lt;18 years from a Canadian cohort were analysed. Atazanavir Cmin were estimated using a half-life of 10.10 and 5.58 hours with and without ritonavir boosting respectively, for levels taken more than 4 hours post-dose. Cmin below 0.15 was considered subtherapeutic. The investigators evaluated associations between dose Cmin and bilirubin Cmin.<\/p>\n<p>Data from 15 participants and 35 TDMs were included in the analysis; the majority (93%) was black and 67% were girls. Their median age was 15 years (range 8-18), weight 49 kg (range 29-74) and body surface area 1.47 m2 (range 1.00 -1.88). The median atazanavir dose was 4.42 mg\/kg (range 3.40 \u2013 10.49) and 150 mg\/m2 (range 125-299); most (74%) doses were boosted with ritonavir.<\/p>\n<p>The median Cmin for TDMs for participants receiving unboosted atazanavir (n=5) was 0.05 mg\/L (range 0-0.25); 60% of these were in the subtherapeutic range. For those receiving boosted atazanavir (n=19), median Cmin was 0.79 mg\/L (range 0-1.85), 11% subtherapeutic. Cmin could not be evaluated in 11 TDMs.<\/p>\n<p>The investigators found no association between Cmin and dose: mg\/kg, p=0.81 and mg\/m2, p=0.75; this remained similar after adjustment for ritonavir use. They found bilirubin concentrations of 18 ug\/L to be predictive of Cmin &gt; 0.15 mg\/L with 95% sensitivity and 80% specificity, AUC 0.91 (95% CI 0.76 \u2013 1.00). They noted that the results need to be confirmed in prospective studies.<\/p>\n<p>Reference:<\/p>\n<p>Wong A et al. Biliruben as a surrogate marker for atazanavir concentrations in a pediatric population. 14th International Workshop on Clinical Pharmacology. 22-24 April 2013. Amsterdam. Poster abstract P_14.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Polly Clayden, HIV i-Base Findings for a study looking at paediatric atazanavir dosing and plasma bilirubin as a possible surrogate for atazanavir therapeutic drug monitoring (TDM) were presented at the 14th International Workshop on Clinical Pharmacology. Although atazanavir dose is &hellip;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,32,34],"tags":[174],"class_list":["post-21396","post","type-post","status-publish","format-standard","hentry","category-conference-reports","category-paediatric-care","category-pk-and-drug-interactions","tag-pk-workshop-14th-2013"],"_links":{"self":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/21396","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/comments?post=21396"}],"version-history":[{"count":0,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/posts\/21396\/revisions"}],"wp:attachment":[{"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/media?parent=21396"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/categories?post=21396"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i-base.info\/htb\/wp-json\/wp\/v2\/tags?post=21396"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}