77.做為cidofovir之輔助治療？
(A)amitriptyline
(B)benztropine mesylate
(C)penicillin
(D)probenecid

probenecid 可以抑制腎小管表皮細胞再吸收cidofovir，進而預防cidofovir 的腎毒性；同時又可以抑制細胞主動分泌cidofovir、減緩排除，進而增加cidofovir 的濃度

The most important toxicity of the drug is renal which can be reduced by coadministration with saline and probenecid; probenecid blocks active renal tubular secretion (see below). Dosing probenecid prior to, two hours after, and eight hours after cidofovir infusion may result in the doubling of serum concentrations. The fact that probenecid protects against nephrotoxicity and yet decreases renal clearance of the drug, may seem paradoxical. However, the drug appears to prevent damage to proximal renal tubular epithelial cells by preventing the uptake of cidofovir into these cells; at the same time, drug concentrations can decrease more slowly since these same renal cells are responsible for secreting the drug into the urine

UpToDate Cidofovir: An overview

(補充)使用劑量：使用cidofovir前３小時用probenecid 2 g，使用cidofovir後2-8小時使用probenecid 1 g

To reduce possible nephrotoxicity, intravenous prehydration with normal saline and administration of probenecid must be used with each infusing of the antiviral cidofovir. The recommended standard-dose probenecid (SDP) regimen is 2 g at 3 hours before cidofovir, then 1 g at 2 and 8 hours after cidofovir (total 4 g).

Ref: https://www.ncbi.nlm.nih.gov/pubmed/12520627

probenecid 抑制尿酸重吸收 排尿酸 

cidofovir　什麼結構? purine結構

你悟了嗎?

更正一下4F:cyidofovir是cytosine結構

資料來源:Foye's 7th 

CIDOFOVIR-Mechanism of Action Cidofovir (1-[(S)-3-hydroxy-2-(phosphonomethoxy)propyl]cytosine) is a synthetic acyclicpurine nucleotide analog of cytosine.

probenecid(酸藥) 會減少 indomethacin, penicillin, methotrexate(酸藥) 之排泄
(上白老師藥理的時候抄的)

請問 cidofovir 也是這個原因嗎？我看結構上有磷酸
另外好像有背到 cidofovir 有腎毒性