Azithromycin Prevents Relapses of Nephrotic Syndrome in a 2-year Old Child

A case report published in the Clinical Kidney Journal reported the use of the antibiotic azithromycin in preventing relapses of idiopathic nephrotic syndrome in a 2 year old child. Nephrotic syndrome is an immune-based kidney disease characterized by loss of protein in the urine, resulting in low protein levels in the blood and fluid accumulation. Nephrotic syndrome may be idiopathic where the cause is not known, or secondary due to other conditions like systemic lupus erythematosus.

Idiopathic nephrotic syndrome includes minimal-change nephrotic syndrome (MCNS) and focal segmental glomerulosclerosis (FSGS). The fluid accumulation may be mild or severe resulting in swollen legs and a bulging abdomen. The diagnosis is based on urine and blood tests, and imaging tests like kidney ultrasound. Nephrotic syndrome can cause complications like infections and thrombosis (formation of blood clots within blood vessels).

Corticosteroids like prednisolone are the mainstay of treatment for nephrotic syndrome. Unfortunately, several children show relapses following treatment, and require repeat courses. The long term use of corticosteroids is associated with several adverse effects which include bone thinning, gastritis, weight gain, repeated infections, skin thinning and muscle weakness. Some patients are put on immunosuppressive treatment, which is again associated with side effects. A safer alternative would therefore be preferred, especially in children who require long-term treatment.

Doctors have reported the successful use of azithromycin in a child with idiopathic nephrotic syndrome in preventing relapses. Azithromycin is an antibiotic which belongs to the macrolide group, the same group that also includes erythromycin and clarithromycin. Its once a day administration due to its prolonged residence in tissues, its stability in acid, lesser drug interactions and effect against a larger spectrum of bacteria make it a preferred alternative to erythromycin.

The 2-year-old boy with idiopathic nephrotic syndrome was first treated with oral prednisolone, with which he recovered. One month after stopping treatment, the child suffered from a relapse that did not respond to dietary restriction but responded to oral prednisolone again. However, reducing the dose of prednisolone again resulted in a relapse.

When the child was given azithromycin daily for 3 days, there was a remarkable improvement in the disappearance of the proteins in the urine. Though they reappeared again, on repeating the treatment with azithromycin, the effect was maintained and the child was free from relapses till the study was sent for publication.

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Though it is not definitely known how azithromycin brought about the effect, the authors of the report put forth several suggestions. These are:

• Azithromycin could be acting as an immunomodulator to prevent relapses.
• Azithromycin may prevent bacterial infections which are a frequent cause of relapses of nephrotic syndrome.
• Azithromycin may have some effect on the kidney cells to reduce the excretion of protein in the urine.

Another report published earlier also suggested that azithromycin suppressed disease activity in nephrotic syndrome.

Though the effect of azithromycin in preventing relapses of nephrotic syndrome cannot be confirmed only based on the case report, it is worth further investigation. Azithromycin has already been in the market for a considerable amount of time. Its adverse effect profile is much better when compared to steroids or immunosuppressive drugs, and would be a good alternative. Its safety on long-term use, however, will also have to be established before it is used for this purpose.

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Reference:

1. Hara H, Hirano D. Azithromycin suppressed relapses of idiopathic nephrotic syndrome in a child. Clinical Kidney Journal, sfx099, - (https://doi.org/10.1093/ckj/sfx099)

Source-Medindia