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Contrast-Induced Nephropathy Prevention

N-Acetylcysteine (Contrast Nephropathy)

Brand names: Parvolex (IV), effervescent tablets (oral)

N-acetylcysteine has been used, often orally, in attempts to prevent contrast-induced nephropathy in patients at risk undergoing contrast imaging, though its benefit is uncertain.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It is a thiol-containing antioxidant and glutathione precursor proposed to reduce contrast-related oxidative stress and to have vasodilatory effects on the renal vasculature.

Prescribing in practice

  • Evidence for preventing contrast-induced nephropathy is weak and inconsistent, and it should not replace the mainstay of adequate intravenous hydration in at-risk patients.
  • It is generally well tolerated, with the oral route carrying few risks in this setting.
  • Hydration and minimising contrast volume remain the priorities in renal protection.

Monitoring

Monitor renal function (serum creatinine) around the time of contrast exposure in at-risk patients.

Counselling the patient

  • Staying well hydrated around the time of your scan is the most important protective step.
  • Take any prescribed preventive medication as directed before and after the procedure.
  • Report reduced urine output or swelling after the procedure.

Evidence & guidelines

Large trials such as PRESERVE found no benefit of N-acetylcysteine over placebo for preventing contrast-associated kidney injury, with hydration being the key measure.

Reference: PRESERVE Trial (Weisbord et al. NEJM 2018); NICE CKD Guidelines; SPC Parvolex; RCR Guidance on Contrast Media; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

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