Case Presentation:
A 66 year old man presents with progressive weakness and diffuse myalgias. He has been on antibiotic treatment for an infected iliac artery stent which was removed on recent hospitalization. He was discharged in good condition on IV daptomycin and ceftriaxone. He presented one week after discharge and was found with an acutely elevated Creatine Phosphokinase of 3200 (reference range 23-240 IU/L). He had a normal level on previous discharge. He was admitted for treatment of non-traumatic rhabdomyolysis. He appropriately responded to fluid resuscitation and supportive care with an appropriate decline in CPK and symptoms. Upon review of his recent medication history, he had previously been on rosuvastatin which was discontinued prior to starting daptomycin. In its place, the patient decided to take a Red Yeast Rice supplement for its reported heart health benefits. Due to this extra information, he was suspected to have developed acute rhabdomyolysis from the interaction of daptomycin and Red Yeast Rice. He rapidly improved and was discharge on alternate antibiotics to complete therapy.
Discussion:
Red Yeast Rice is a Chinese herbal supplement produced when rice is fermented by the yeast, Monascus purpureus. It has been used as a food colorant and in traditional medicines for many years. More recently it has been promoted for its cholesterol lowering effect. The yeast produces a series of compounds called Monacolins. In particular, Monacolin K is found to be chemically identical to lovastatin with the same ability to inhibit HMG-CoA Reductase and lower cholesterol levels. The U.S. Food and Drug Administration (FDA) considers Monacolin K an unapproved new drug rather than a dietary supplement. It prohibits the sale of Red Yeast Rice supplements if it contains more than trace amounts of Monacolin K. Despite this, Red Yeast Rice remains widely available in supplements and it has been difficult to regulate their concentrations of Monacolin K. It is undetermined whether Red Yeast Rice supplements without Monacolin K continues to have cholesterol lowering benefits.
Conclusions:
The Hospitalist should be aware that Red Yeast Rice has the potential of having similar effects to approved HMG-CoA reductase inhibitors both for its cholesterol lowering effects as well as interactions. A dietary supplement review should always be performed during review of home medications with consideration for their potential physiologic effects.