Probenecid Digoxin

Liver disease or injury may impair bile secretion and thereby lead to accumulation of certain drugs, for example probenecid, digoxin, and diethylstilbestrol. Impairment of liver function can lead to decreased rates of both drug metabolism and secretion of drugs into bile. These two processes, of course, are frequently interrelated, since many drugs are candidates for biliary secretion only after appropriate metabolism has occurred. 

Certain drugs are excreted in urine only in small amounts but appear in high concentrations in the bile for example, erythromycin, novobiocin, tetracycline, phenolphthalein etc. The abnormality or any disease related to liver may impair bile secretion which can lead to the accumulation of certain drugs like probenecid, digoxin etc. This can also lead to decreased drug metabolism and decreased rates of secretion of drugs into bile. 

There is an increased risk of toxicity of MTX when administered with the NSAIDs, salicylates, oral antidiabetic drugs, phenytoin, tetracycline, and probenecid. There is an additive bone marrow depressant effect when administered with other drug known to depress the bone marrow or with radiation therapy. There is an increased risk for nephrotoxicity when MTX is administered with other drug that cause nephrotoxicity. When penicillamine is administered with digoxin, decreased blood levels of digoxin may occur. There is a decreased absorption of penicillamine when the dmg is administered with food, iron preparations, and antacids. 

Drugs that may affect ACEIs may include antacids, capsaicin, indomethacin, phenothiazines, probenecid, and rifampin. Drugs that may be affected by ACEIs include allopurinol, digoxin, lithium, potassium preparations/potassium-sparing diuretics, and tetracycline. 

Famciclovir (Famvir) [Antiviral/Synthetic Nucleoside] Uses Acute h pes zoster (shingles) genital h pes Action X Viral DNA synth Dose Zoster 500 mg PO q8h x7 d Simplex 125-250 mg PO bid X w/ renal impair Caution [B, -] Contra Component sensitivity Disp Tabs SE Fatigue, dizziness, HA, pruritus, N/D Interactions t Effects cimetidine, probenecid, theophylline t effects OF digoxin EMS None OD Sxs unknown, but may cause hallucinations, Szs and reduced kidney Fxn... 

Interference with active transport. Organic acids are passed from the blood into the urine by active transport across the renal tubular epithelium. Penicillin is mostly excreted in this way. Probenecid, an organic acid that competes successfully with penicillin for this transport system, may be used to prolong the action of penicillin when repeated administration is impracticable, e.g. in sexually transmitted diseases, where compliance is notoriously poor. Interference with renal excretion of methotrexate by aspirin, of zidovudine by probenecid and of digoxin by quinidine, contribute to the potentially harmful interactions with these combinations. 

Clinically important, potentially hazardous interactions with aliskiren, amikacin, amyl nitrite, digoxin, gentamicin, hydrocortisone, kanamycin, mivacurium, neomycin, probenecid, streptomycin, tobramycin... 

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