Most Common Cause of Renal Failure in IV Drug Users
The most common cause of renal failure in intravenous drug users is rhabdomyolysis with myoglobinuric acute kidney injury, typically occurring after heroin or other depressant drug overdose. 1, 2
Primary Mechanism: Rhabdomyolysis-Induced AKI
Rhabdomyolysis accounts for the majority of acute renal failure cases in IV drug users, occurring when prolonged immobilization during drug-induced coma leads to muscle breakdown and myoglobin release that causes direct tubular toxicity. 1, 2
The clinical presentation is characterized by markedly elevated creatine kinase levels (often >100,000 U/L in severe cases requiring dialysis), myoglobinuria, and a disproportionate rise in serum creatinine relative to blood urea nitrogen. 1, 2
Heroin overdose is the most frequently implicated substance, followed by alcohol and other CNS depressants, with the mechanism involving prolonged unconsciousness leading to pressure-induced muscle necrosis. 1, 3, 2
Key Predictors of Dialysis Requirement
When rhabdomyolysis occurs in IV drug users, specific factors predict the need for dialysis:
- Admission creatine kinase >115,000 U/L (versus 9,000 U/L in non-dialysis cases). 1
- Initial urine output <0.9 L/24 hours (versus 3.9 L/24 hours in those not requiring dialysis). 1
- Admission creatinine >3.8 mg/dL at presentation. 1
Secondary Renal Pathologies in IV Drug Users
While rhabdomyolysis is most common acutely, chronic renal disease patterns also occur:
Focal segmental glomerulosclerosis (FSGS) is the predominant chronic lesion in black heroin users, presenting with nephrotic-range proteinuria and rapid progression to end-stage renal disease. 4, 5
Membranoproliferative glomerulonephritis occurs more commonly in white heroin users, though the incidence of "heroin nephropathy" has declined since hepatitis C and HIV surveillance began. 5
The pathophysiology likely involves immunologically-mediated injury from heroin, its adulterants, or co-infections (74% hepatitis C positive in one series), rather than direct drug toxicity alone. 1, 4, 5
Clinical Pitfalls and Associated Complications
Compartment syndrome requiring fasciotomy occurs in 22% of cases with rhabdomyolysis, and 37% have significant residual limb weakness at discharge despite renal recovery. 1
Pneumonia develops in 52% of patients, with 26% requiring mechanical ventilation, complicating the clinical course beyond the renal injury. 1
Profound hyperuricemia and initial hypocalcemia followed by rebound hypercalcemia during the diuretic phase are characteristic biochemical patterns that distinguish myoglobinuric AKI from other causes. 2
Despite the severity of presentation, renal prognosis is generally excellent with supportive care, as all patients in major series achieved independent renal function at follow-up when rhabdomyolysis was the primary mechanism. 1, 2
Management Priorities
Aggressive volume resuscitation and urine alkalinization should be initiated immediately when rhabdomyolysis is suspected, as early reversal of AKI from decreased renal perfusion improves survival. 6
Nephrotoxic agents must be avoided entirely during the acute phase, as the risk of AKI more than doubles when multiple nephrotoxic medications are administered simultaneously. 6
Dialysis is typically required for 14 days on average (range 3-26 days) in severe cases, but recovery of independent renal function is expected. 1