Carrillo Norte Juan Antonio
Departamento de Terapéutica Médico-Quirúrgica, Facultad de Medicina de Badajoz, Universidad de Extremadura.
Rev Enferm. 2011 Sep;34(9):24-31.
The main route of excretion of drugs is the kidney. Other routes include the lungs; breast milk; sweat; tears, and genital secretions (alarming if the patient is not expecting the orange-red discoloration caused by rifampicin); bile (leading to recirculation of some compounds, for example chloramphenicol, whose inactive metabolites are reactivated by hydrolysis in the gut, morphine, rifampicin, tetracyclines, and digoxin); and saliva (sometimes used in monitoring drug concentrations in body fluids). Three processes determine the renal excretion of drugs: glomerular filtration, passive tubular reabsorption and active tubular secretion. Thus, total renal excretion = excretion by filtration + excretion by secretion - retention by reabsorption. If an active drug is metabolized mainly to inactive compounds, renal function will not greatly affect elimination of the parent compound. However, if the drug or an active metabolite is excreted unchanged via the kidneys, changes in renal function (i.e. chronic renal failure) will influence its elimination. Therefore, dose adjustment of the drug should be recommended.
药物排泄的主要途径是肾脏。其他途径包括肺；母乳；汗液；眼泪以及生殖分泌物（如果患者没有预料到利福平会导致橙红色变色，这会令人担忧）；胆汁（导致某些化合物的再循环，例如氯霉素，其无活性代谢物在肠道中通过水解重新激活，吗啡、利福平、四环素和地高辛）；以及唾液（有时用于监测体液中的药物浓度）。有三个过程决定药物的肾脏排泄：肾小球滤过、被动肾小管重吸收和主动肾小管分泌。因此，肾脏总排泄量=滤过排泄量+分泌排泄量-重吸收潴留量。如果活性药物主要代谢为无活性化合物，肾功能不会对母体化合物的消除产生很大影响。然而，如果药物或活性代谢物通过肾脏原样排泄，肾功能的变化（即慢性肾衰竭）将影响其消除。因此，应建议调整药物剂量。
