Ritodrine-induced rhabdomyolysis and psychiatric symptoms: a case report and literature review

BACKGROUND: Ritodrine hydrochloride, a β2-adrenergic agonist, has been widely used in Asia and Europe to treat preterm labor in pregnant women. It has some typical side effects, such as palpitations, pulmonary edema, and hypokalemia. Here, we report a case of rhabdomyolysis and psychiatric symptoms might be associated with intravenous ritodrine. CASE PRESENTATION: A 32-year-old Chinese primigravida woman who was pregnant with twins by in vitro fertilization-embryo transfer was diagnosed with placenta previa and threatened abortion at 21 gestational weeks (GW). The patient was then treated with ritodrine hydrochloride. The initial dose of ritodrine was 150 μg/min, gradually increasing to 360 μg/min at 23(5/7) GW and 400 μg/min at 27(1/7) GW. Magnesium sulfate was added to the ritodrine regimen at 21(5/7) GW in dosage of 1-2 g/h. Psychiatric symptoms appeared at 24(5/7), 26(5/7), and 27(3/7) GW, manifesting as depression, anxiety, and suicidal tendencies. Severe muscle pain in her limbs and general weakness appeared after six weeks of ritodrine administration, which might have been a sign of rhabdomyolysis resulting from ritodrine administration. After ceasing the administration of ritodrine, the muscle pain and relevant data from laboratory tests on the patient were significantly improved, and her mood was stable. It is worth noting that this is the first time to report psychiatric symptoms may associated with the administration of ritodrine. In addition, we reviewed and analyzed six reported cases of rhabdomyolysis caused by ritodrine. CONCLUSION: Our results suggest that we should pay more attention to the risk of rhabdomyolysis and psychiatric symptoms induced by intravenous ritodrine hydrochloride, especially in patients with a history of neuromuscular disorder, or concomitant use of magnesium sulfate.