Safety and Pharmacokinetics of a Combined Antioxidant Therapy against Myocardial Reperfusion Injury: A Phase 1 Randomized Clinical Trial in Healthy Humans.

Myocardial reperfusion injury (MRI) accounts for up to 50% of the final size in acute myocardial infarction and other conditions associated with ischemia-reperfusion. Currently, there is still no therapy to prevent MRI, but it is well known that oxidative stress has a key role in its mechanism. We previously reduced MRI in rats through a combined antioxidant therapy (CAT) of ascorbic acid, N-acetylcysteine, and deferoxamine. This study determines the safety and pharmacokinetics of CAT in a Phase I clinical trial. Healthy subjects (n = 18) were randomized 2:1 to CAT or placebo (NaCl 0.9% i.v.). Two different doses/infusion rates of CATs were tested in a single 90-minute intravenous infusion. Blood samples were collected at specific times for 180 minutes to measure plasma drug concentrations (ascorbic acid, N-acetylcysteine, and deferoxamine) and oxidative stress biomarkers. Adverse events were registered during infusion and followed for 30 days. Both CAT1 and CAT2 significantly increased the CAT drug concentrations compared to placebo (P < .05). Most of the pharmacokinetic parameters were similar between CAT1 and CAT2. In total, 6 adverse events were reported, all nonserious and observed in CAT1. The ferric-reducing ability of plasma (an antioxidant biomarker) increased in both CAT groups compared to placebo (P < .001). The CAT is safe in humans and a potential treatment for patients with acute myocardial infarction undergoing reperfusion therapy.

Pharmacological Basis for Abrogating Myocardial Reperfusion Injury Through a Multi-Target Combined Antioxidant Therapy.

The main goal of the treatment for acute myocardial infarction is to achieve reperfusion of the affected myocardial tissue, with percutaneous coronary angioplasty being the gold standard procedure. However, this strategy has been associated with additional heart damage termed "lethal reperfusion injury," which is responsible for up to half of the final infarct size. Among the possible underlying mechanisms that are likely to explain this damage, studies suggest that oxidative stress plays a key role. Although this has not been translated into clinical benefits in most studies, recent preclinical studies reported promising results and a possible synergy with the combined use of vitamin C (VC), N-acetylcysteine (NAC), and deferoxamine (DFO). However, to implement a combined therapy with these drugs for patients requires further studies to understand their pharmacokinetic properties. Available data of the clinical trials have not been validated by looking into the pharmacokinetics in their design. Therefore, this article presents an update and comparison of the evidence for the efficacy of these administration schemes for each drug in cardioprotection, their pharmacokinetic properties and mechanisms of action for their use against "lethal reperfusion injury." To achieve a cardioprotective effect using a new pharmacological strategy before the onset of reperfusion, it is helpful to consider the pharmacokinetics of each drug. In this regard, to design a fast and short pharmacologic therapeutic strategy, theoretically VC and DFO concentrations could be modeled by a one-compartment model whereas NAC could be modeled by a three-compartment model with an initial short half-life.