Arrhythmias (Heart Rhythm Disturbances) and N-Acetyl Cysteine (NAC)

N-acetyl cysteine (NAC), a modified version of a dietary amino acid, may reduce the incidence of atrial fibrillation (a specific kind of arrhythmia) following open-heart surgery. Atrial fibrillation is a common complication of this kind of procedure.

The exact effect of NAC on arrhythmias is not clear. When taken orally, NAC is thought to help the body make the important antioxidant enzyme glutathione.

Read more details about N-Acetyl Cysteine (NAC).

NAC was shown in a pilot placebo-controlled study (115 subjects) to reduce the incidence of atrial fibrillation following open-heart surgery.²¹

Optimal levels of NAC have not been determined. The amount used in studies has varied from 250 to 1,500 mg daily.

It has been suggested that NAC may increase excretion of trace minerals; some evidence, however, suggests that this effect is too minimal to make a real difference.⁴⁷ Prudence suggests that individuals taking NAC for an extended period of time should also consider taking a standard multivitamin/multimineral supplement.

• Integrative MD
• Naturopathic doctor
• Clinical nutritionist or registered dietitian

Safety Issues

NAC appears to be a very safe supplement when taken alone, although one study in rats suggests that 60 to 100 times the normal dose can cause liver injury. ¹ As mentioned above, the combination of nitroglycerin and NAC can cause severe headaches. Safety in young children, women who are pregnant or nursing, and individuals with severe liver or kidney disease has not been established.

Interactions You Should Know About

If you are taking nitroglycerin, NAC may cause severe headaches.

1. Badawy AH, Abdel Aal SF, Samour SA. Liver injury associated with N-acetylcysteine administration. J Egypt Soc Parasitol. 19(2):563-71.

21. Ozaydin M, Peker O, Erdogan D, et al. N-acetylcysteine for the prevention of postoperative atrial fibrillation: a prospective, randomized, placebo-controlled pilot study. Eur Heart J. 2008 Feb 8 [Epub ahead of print].
47. Hjortso E, Fomsgaard JS, Fogh-Andersen N. Does N-acetylcysteine increase the excretion of trace metals (calcium, magnesium, iron, zinc and copper) when given orally? Eur J Clin Pharmacol. 1990;39:29-31