Cyclophosphamide
Cytoxan · Oxazaphosphorine alkylator
Vasopressin-independent hyponatremia; hemorrhagic cystitis.
SIADHCYST
MildOpen →
Vinca alkaloid
Vincristine
Oncovin · VCR
A vinca alkaloid that occasionally hijacks ADH signaling to drive hyponatremia.
MildVinca alkaloid · approved 1963
Acute lymphoblastic leukemiaLymphomaPediatric solid tumors
Signature kidney injury
SIADH / Hyponatremia
Vincristine-associated SIADH with hyponatremia is a recognized but uncommon, largely case-level adverse effect; a global pharmacovigilance analysis estimated a reporting rate of about 1.3 per 100,000 treated patients, with a possible over-representation in Asian patients. FAERS disproportionality analysis also flags inappropriate ADH secretion as a vinca-class signal.
Source: Hammond et al., Pharmacoepidemiol Drug Saf 2002
Mechanism of kidney injury
Thought to cause inappropriate antidiuretic hormone release/effect, plausibly via neurotoxic action on the hypothalamic-neurohypophyseal axis (consistent with its dose-limiting peripheral and autonomic neuropathy), increasing aquaporin-2-mediated water reabsorption in the collecting duct. The result is euvolemic, dilutional hyponatremia rather than structural kidney injury.
Clinical presentation
Euvolemic hyponatremia with low serum osmolality (<275 mOsm/kg), inappropriately concentrated urine (urine osmolality typically >100 mOsm/kg), and urine sodium usually >30-40 mmol/L; normal thyroid/adrenal/renal function. Symptoms range from malaise and headache to confusion, seizures, or coma if severe.
Onset
Days after dosing, often within the first 1-2 cycles; resolves after the drug is withheld.
Reversibility
Reversible
Anticancer mechanism
Binds beta-tubulin at the vinca domain and inhibits microtubule polymerization, disrupting the mitotic spindle and arresting dividing cells at metaphase. Core agent in leukemias, lymphomas, and many pediatric and combination regimens.
Management
Fluid restriction is first-line for mild/moderate cases. For severe or symptomatic hyponatremia use 3% hypertonic saline, correcting by 4-6 mmol/L over the first hours and no more than 8-10 mmol/L per 24 h to avoid osmotic demyelination. SIADH usually resolves after the drug is withheld; vaptans/urea are second-line.
Risk factors
- Concurrent SIADH-promoting drugs or conditions
- Possible Asian ancestry (reporting signal)
- Excess free-water intake or hypotonic IV fluids during the episode
- Co-existing vincristine neurotoxicity (a clinical co-marker)
Prevention
- Monitor serum sodium during therapy, especially early cycles
- Avoid hypotonic maintenance fluids in at-risk patients
- Recognize neurotoxicity as a possible co-marker prompting closer sodium checks
Note · SIADH leading to hyponatremia is the signature renal/electrolyte effect; the kidneys themselves are structurally spared.
Clinical depth
Renal dose adjustment
Hepatically (CYP3A) metabolized and biliary excreted - no renal dose adjustment. Reduce dose for hepatic dysfunction/hyperbilirubinemia. Note the absolute dose cap to limit neurotoxicity; never administer intrathecally (fatal).
Dialyzability & ESKD dosing
Highly tissue-bound with a very large volume of distribution; not dialyzable. Hyponatremia is managed with fluid/sodium strategies, not dialysis.
Differential diagnosis
Drug-induced SIADH (euvolemic, concentrated urine, urine Na >30) vs hypovolemic hyponatremia (low urine Na, volume depletion) vs hypervolemic states (heart failure, cirrhosis) vs malignancy-related ectopic ADH from the tumor itself. Volume assessment and urine indices separate them.
Monitoring
- Serum sodium and osmolality during early cycles or with neurologic symptoms
- Urine osmolality and urine sodium if hyponatremia develops
- Neurologic exam for peripheral/autonomic neuropathy
Key trials & series
- Hammond Pharmacoepidemiol Drug Saf 2002 global safety-database analysis
- Zhong Expert Opin Drug Saf 2024 FAERS vinca-alkaloid disproportionality analysis
Clinical pearls
- Vincristine hyponatremia is SIADH - restrict water first, reserve hypertonic saline for seizures/coma.
- Correct no faster than 8 mmol/L/24 h to avoid osmotic demyelination.
- Coexisting neuropathy supports a neurotoxic mechanism for the inappropriate antidiuresis.
Where it strikes
Nephron segments
Distal Tubule / Collecting Duct
Fine-tuning of Na, K, Mg, acid & water
Injury signatures
SIADH / HyponatremiaElectrolyte Wasting
Beyond the kidney
Class-level context for the major non-renal toxicities of vinca alkaloids.
Ophthalmic
Keratopathy, uveitis, retinopathy
- Visual disturbance (crizotinib)
Hepatic / Liver
Transaminitis, hepatitis, VOD/SOS
- Transaminitis
Neurologic
Neuropathy, encephalopathy, ICANS, PRES
- CNS effects (lorlatinib)
Evidence
6 peer-reviewed references. Citation metadata via PubMed / NLM.
LandmarkHyponatremia and syndrome of inappropriate anti-diuretic hormone reported with the use of Vincristine: an over-representation of Asians?Hammond IW et al. · Pharmacoepidemiol Drug Saf 2002 · PMID 12051122Global safety-database analysis of vincristine-associated SIADH/hyponatremia and its reporting rate.PMIDA real-world pharmacovigilance study using disproportionality analysis of FDA Adverse Event Reporting System events for vinca alkaloids: comparing vinorelbine and vincristine.Zhong C et al. · Expert Opin Drug Saf 2024 · PMID 39340205FAERS analysis identifying inappropriate ADH secretion as a shared vinca-alkaloid signal.PMIDPathophysiology of Drug-Induced Hyponatremia.Kim GH et al. · J Clin Med 2022 · PMID 36233678Mechanistic review identifying vincristine among agents causing sustained ADH-mediated (SIADH) hyponatremia.PMIDDiagnosis and Management of Hyponatremia: A Review.Adrogué HJ et al. · JAMA 2022 · PMID 35852524Authoritative guidance on SIADH evaluation, hypertonic saline use, and safe correction limits to prevent osmotic demyelination.PMIDAnti-Microtubule Drugs.Florian S et al. · Methods Mol Biol 2016 · PMID 27193863Reviews the tubulin-binding mechanism of vinca alkaloids underlying their antimitotic and neurotoxic effects.PMIDOnconephrology: The intersections between the kidney and cancer.Rosner MH et al. · CA Cancer J Clin 2020 · PMID 32853404Onconephrology review covering chemotherapy-associated electrolyte disorders including SIADH.