Acute tubulointerstitial nephritis (ATIN) is an important cause of renal insufficiency. It is characterized by inflammatory changes in the interstitium and tubuli. In general, the glomeruli are not involved. Tubulointerstitial nephritis is most common caused by medication. Other causes are infections and auto-immune diseases.

We describe three patient histories of a 72-year old and a 83-year old woman and a 83-year old man, who had acute tubulointerstitial nephritis because of prescribed medication. In two cases, the patients developed renal insufficiency after the use of protonpumpinhibitors, which are often prescribed drugs by specialists and general practitioners and nowadays even belong to the ‘over-the-counter drugs’. The diagnoses were proven with biopsy of the kidney. The other case prescribes a patient who developed acute tubulointerstitial nephritis because of the use of flucloxacilline. This patient had a subfebrile temperature and her peripheral blood showed eosinophilia, which makes the diagnosis highly suggestive. In all three cases withdrawal of the causing medicine in combination with steroid treatment improved kidney function dramatically.

Often prescribed medication such as proton pump inhibitors, antibiotics and nonsteroidal anti-inflammatory drugs can cause acute tubulointerstitial nephritis. The exact incidence of tubulointerstitial nephritis is unknown, but studies show that of all patients who had a kidney biopsy because of renal failure, in 6-27% tubulointerstitial nephritis was found. The time between the use of the offending drug and the development of kidney failure is not dose related and is ranging from days to months. A part of patients develop ‘allergic-type’ symptoms, like maculopapular rash, eosinphilia, arthralgia and fever. Urine samples can show pyuria, leukocyte casts and eosinophiluria. Proteinuria can be present in variable degrees, but usually less than one gram in 24 hours. The only definitive method of establishing the diagnosis of acute tubulointerstitial nephritis is renal biopsy. This should be considered when the diagnosis in unclear, when discontinuation of the medication does not improve kidney function or when kidney function deteriorates. In most patients renal function recovers after withdrawal of the causing medicine, but in 23% of patients partial renal insufficiency persists. Multiple studies show that early steroid treatment improve the recovery of renal function in patients with drug-induced tubulointerstitial nephritis, when using prednisolone 1 mg/kg a day for one or two weeks (with a maximum of 40 to 60 milligrams a day). However, there are no randomized controlled trials that prove this.

Specialists and general practitioners should be aware of the disease ‘medication induced tubulointerstitial nephritis’, which is in potential dangerous and can cause serious renal failure. It is an important diagnostic consideration, because renal failure may be reversible when discontinuing the use of the offending drug. Prescription of medication should be well considered and monitoring of kidney function is very important to prevent unnecessary medication-induced renal failure.

This supplementary information is presented as submitted by the corresponding author. It has not been copy-edited and NTvG does not guarantee the accuracy of the data.