Accumulation. Tenofovir, or viread, (tenofovir) is a powerful antiviral medication for hiv. It has, in rare cases, been thought to contribute to renal failure. The thought is that the drug and metabolites of the drug accumulate in the tubule of the kidneys, causing damage to the filtering system. However, some studies have shown that tenovir is no more toxic than other antivirals.
Accumulation. Tenofovir exits the body only through the kidneys and if the levels of drug get too high, the part of the kidney called the proximal tubule begins to accumulate the drug. Result - acute renal failure due to death of the proximal tubule cells. Other things can also happen when the proximal tubules are injured, but there's not enough space to elaborate.