Distribution of drugs
1106 cases of DAMAR involved 114 drugs. Drugs distributed in nervous system, antiinfectives for systemic use and cardiovascular system mainly.
A large portion of DAMAR were associated with neurologic medications, up to 21.07%. Most drugs in this kind were proved muscular toxic by random clinical trials and clinical practice, which were also written in their labels. Mechanism of antiepileptics caused DAMAR is interference of mitochondrial impairment, while psycholeptics and analgesics leads to muscle cell necrotizing by hypoxia [21].
Antiinfectives for systemic use were also the cause of DAMAR in many cases. Despite the relatively large volume of case-based evidence, the pathophysiology of fluoroquinolone-induced muscle adverse reaction is still unclear. The inhibitory effect on the formation of oxygen-derived reactive molecules [22] might be a reason. Linezolid-induced muscle adverse reaction is associated with maintenance of substantial mitochondrial function [23].
Cardiovascular system drug, especially statins of lipid modifying agents, was known to be muscle toxic. Statins alone accounted for 8.86% of all suspected drugs in our study. It is reported that gene regulation, mitochondrial disfunction, immunologically mediation and other mechanisms are associated with SMAS [24]. Concomitant drugs may interact and influence risk of muscle symptoms by CYP3A4 and other elimination process way [25]. The incidence of SAMS was estimated at 1-2% by national lipid association[26], while serious muscle injury, including rhabdomyolysis was estimated at under 0.1% in general patient population by the American heart association [4]. Incidence from our study is consistent with these studies above.