Benefit of acetylcysteine for prevention of contrast-induced nephropathy after primary angioplasty

N-Acetylcysteine inhibits platelet-monocyte conjugation in patients with type 2 diabetes with depleted intraplatelet glutathione: a randomised controlled trial

AIMS/HYPOTHESIS

The aim of this study was to determine whether oral dosing with N-acetylcysteine (NAC) increases intraplatelet levels of the antioxidant, glutathione (GSH), and reduces platelet-monocyte conjugation in blood from patients with type 2 diabetes.

METHODS

In this placebo-controlled randomised crossover study, the effect of oral NAC dosing on platelet-monocyte conjugation and intraplatelet GSH was investigated in patients with type 2 diabetes (eligibility criteria: men or post-menopausal women with well-controlled diabetes (HbA(1c) < 10%), not on aspirin or statins). Patients (n = 14; age range 43-79 years, HbA(1c) = 6.9 ± 0.9% [52.3 ± 10.3 mmol/mol]) visited the Highland Clinical Research Facility, Inverness, UK on day 0 and day 7 for each arm of the study. Blood was sampled before and 2 h after oral administration of placebo or NAC (1,200 mg) on day 0 and day 7. Patients received placebo or NAC capsules for once-daily dosing on the intervening days. The order of administration of NAC and placebo was allocated by a central office and all patients and research staff involved in the study were blinded to the allocation until after the study was complete and the data fully analysed. The primary outcome for the study was platelet-monocyte conjugation.

RESULTS

Oral NAC reduced platelet-monocyte conjugation (from 53.1 ± 4.5% to 42.5 ± 3.9%) at 2 h after administration and the effect was maintained after 7 days of dosing. Intraplatelet GSH was raised in individuals with depleted GSH and there was a negative correlation between baseline intraplatelet GSH and platelet-monocyte conjugation. There were no adverse events.

CONCLUSIONS/INTERPRETATION

The NAC-induced normalisation of intraplatelet GSH, coupled with a reduction in platelet-monocyte conjugation, suggests that NAC might help to reduce atherothrombotic risk in type 2 diabetes.

FUNDING

Chief Scientist Office (CZB/4/622), Scottish Funding Council, Highlands & Islands Enterprise and European Regional Development Fund.

TRIAL REGISTRATION

isrctn.org ISRCTN89304265.

[Medication-induced impairment of renal function: what is important?]

Non-steroidal antiphlogistics and COX-2 inhibitors routinely cause sodium retention and a blood pressure increase by about 5 mmHg, a decrease in renal function (by about 10 ml/min) and in 1-2% an acute renal failure. Prevention is possible by short-term, low-dose application, avoidance of dehydration, controlling serum creatinine levels 1 week after start of treatment in high-risk groups. Aminoglycosides cause acute renal failure in 10-20% which can be prevented by once daily dosing, meticulous drug monitoring. Radio contrast media cause, mostly dependent on baseline renal function, in 0-50% a radiocontrast-induced nephropathy. This can be prohibited with hydration, low volume of contrast medium, and low- (or iso)osmolar contrast medium. New preparations of vancomycin go along with a greatly reduced rate of nephrotoxicity. Drug monitoring and avoidance of a combination therapy with aminoglycosides will help to reduce toxicity. Medication-induced acute interstitial nephritis is a relevant differential diagnosis in acute renal failure: stop implicated medication, consider steroid application!