Navigating Your Treatment Options for FSGS

Treatment for Focal Segmental Glomerulosclerosis (FSGS) is not “one size fits all.” Because FSGS is a pattern of injury with many different causes, your treatment plan depends entirely on why your kidney filters are being damaged ^[1], as well as your nephrotic syndrome status, eGFR, severity, and other health conditions. The KDIGO 2021 guidelines—the global standard for kidney care—emphasize that the first step in treatment is correctly identifying the cause to avoid unnecessary or harmful medications ^[2].

Treating Primary FSGS

In Primary FSGS, it is proposed that an unidentified circulating factor in the blood is actively injuring the kidneys ^[3]. Because this is an active, aggressive process, treatment focuses on calming the immune system (immunosuppression), particularly for patients with nephrotic syndrome.

• First-Line: Glucocorticoids (Steroids): High-dose steroids, such as prednisone, are the standard initial treatment for adults with primary FSGS and nephrotic syndrome ^[4]. Unlike many other conditions where steroids are taken for a few days, FSGS often requires a prolonged course—sometimes up to 16 weeks—to see if the kidneys will respond ^[5].
  • Safety Note: Steroids can cause infection, elevated blood sugar, increased blood pressure, mood and sleep changes, bone effects, gastrointestinal issues, and eye complications. An initial trial and taper are individualized, and you should never stop taking steroids abruptly.
• Second-Line: Calcineurin Inhibitors (CNIs): If the disease is steroid-resistant (does not improve with steroids) or steroid-dependent (returns as soon as steroids are lowered), doctors often switch to a class of drugs called calcineurin inhibitors, such as cyclosporine or tacrolimus ^[6][7].
  • Safety Note: Tacrolimus and cyclosporine require drug-level monitoring. Side effects can include kidney toxicity, high blood pressure, and tremors. Report adverse effects to your doctor rather than altering the dose independently.
• The Goal: The main goal is to achieve remission, where protein levels in the urine drop significantly. Remission is the strongest indicator that your kidneys will remain healthy over the long term ^[8].

Treating Secondary and Genetic FSGS

For people with Secondary FSGS (caused by things like obesity, high blood pressure, or viruses) or Genetic FSGS, the problem is usually structural or related to an underlying stressor rather than an immune attack ^[9].

• Avoiding Immunosuppression: In these cases, steroids and other immune-suppressing drugs are generally avoided because they expose patients to toxicity without clear benefit ^[2][10]. However, treatment decisions belong with a nephrologist, and an alternative immune indication or later evidence of primary FSGS can change this decision.
• Supportive Care: Instead, the focus is on “supportive care” to protect the remaining healthy filters and reduce the workload on the kidneys ^[8]. This includes:
  • Treating the Root Cause: For example, stopping an offending drug, treating HIV, managing sleep apnea, managing weight, or controlling blood sugar ^[9].
  • Blood Pressure Management: Keeping blood pressure strictly controlled is vital to prevent further scarring ^[10].

Essential Supportive Care for All FSGS

Regardless of the cause, most patients with FSGS will receive supportive therapy to slow the progression of kidney disease ^[8].

1. RAAS Blockade (ACE Inhibitors and ARBs)

Medications known as ACE inhibitors (like lisinopril) or ARBs (like losartan) are often the cornerstone of FSGS management ^[11]. These drugs do two critical things:

• They lower the pressure inside the kidney’s filtering units ^[8].
• They reduce the amount of protein leaking into the urine, which helps prevent further scarring (fibrosis) ^[8].
  Note: These medications are not appropriate for everyone, such as patients with acute kidney injury, severe hyperkalemia, symptomatic low blood pressure, or pregnancy. These two types of drugs should not be taken together, and your doctor will monitor your creatinine and potassium closely after initiation or dose changes ^[11].

2. SGLT2 Inhibitors

Current practice increasingly includes a newer class of drugs called SGLT2 inhibitors (originally for diabetes) for selected patients. They have been shown to provide significant kidney protection and reduce protein loss in proteinuric chronic kidney disease, which can include FSGS ^[12]. Eligibility depends on eGFR, albuminuria, volume status, and other factors. Risks include genital infections, volume depletion, and rare ketoacidosis.

3. Diuretics

If you have significant swelling (edema), your doctor will prescribe “water pills” (diuretics) to help your body get rid of excess fluid and salt ^[8]. Diuretics can cause dehydration and electrolyte abnormalities if overused. These medicines are prescribed and adjusted by your care team rather than self-started or increased.

Why the “Wait and See” Approach Matters

If your diagnosis is FSGS of Undetermined Cause, your doctor may choose to start with supportive care (like blood pressure medication) rather than steroids ^[1]. This allows them to monitor how your body reacts before committing to the potential side effects of stronger immunosuppressants. Correctly identifying the “type” of FSGS is the most important step in ensuring you get the right treatment at the right time ^[2].