Efficacy and side effect of ritodrine and magnesium sulfate in threatened preterm labor

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.

Neonatal hyperkalemia associated with maternal ritodrine: A retrospective study

BACKGROUND

We recently reported on a late preterm infant born at 36 weeks' gestation with serious arrhythmia due to hyperkalemia associated with long-term maternal ritodrine administration. It is unknown whether ritodrine alone increases the risk of neonatal hyperkalemia in infants born at 34-36 weeks' gestation.

METHODS

This single-center, retrospective, cohort study enrolled late preterm infants (34-36 gestational weeks) born between 2004 and 2018. Cases with maternal magnesium sulfate use were not sufficient for statistical analysis and so were excluded from the study. Risk factors for the occurrence of hyperkalemia were determined based on clinical relevance and previous reports.

RESULTS

In all, 212 late preterm infants with maternal ritodrine use and 400 infants without tocolysis were included in the study. Neonatal hyperkalemia occurred in 5.7% (12/212) in the ritodrine group and 1.8% (7/400) in the control group. The risk of neonatal hyperkalemia was significantly increased by maternal ritodrine administration with a crude odds ratio (OR) of 3.37 (95% confidence interval [CI]: 1.30-8.69; p < 0.01) and an adjusted OR of 3.71 (95% CI: 1.41-9.74; p < 0.01) on multivariable analysis. Long-term tocolysis (≥28 days) with ritodrine increased the risk of neonatal hyperkalemia with 9.3% (11/118) of infants developing hyperkalemia (adjusted OR 4.86; 95% CI: 1.59-14.83; p < 0.01). Neonatal hyperkalemia was not found within 2 weeks of ritodrine administration.

CONCLUSION

This research suggests that late preterm infants born after long-term ritodrine administration are at risk of neonatal hyperkalemia and require special attention.

Different impacts of various tocolytic agents on increased risk of postoperative hemorrhage in preterm labor women undergoing Cesarean delivery: A population-based cohort study

Tocolytic agents, commonly used for inhibiting preterm labor, pose the risk of uterine atony, leading to postpartum hemorrhage. This study elucidated the effects of different tocolytic agents on postoperative hemorrhage among women in preterm labor undergoing Cesarean delivery (CD). Data from Taiwan National Health Insurance Research Database were analyzed. The risk (adjusted hazard ratio [aHR] and 95% confidence intervals [CI]) of postoperative hemorrhage in CD women with preterm labor diagnosis using tocolytic agents (Tocolysis group) comparing to CD women not using tocolytic agents (Control group) were determined. Impacts of different tocolytic agents in this regard were also investigated. Our data revealed that the incidence (11.7% vs 2.6%, P < .001) and risk (aHR: 1.21, 95% CI: 1.12-1.31, P < .001) of postoperative hemorrhage were significantly higher in the Tocolysis group (n = 15,317) than in the Control group (n = 244,096). Ritodrine was the most frequently used tocolytic agent (80.5%), followed by combination therapy (using more than one tocolytic agents) (8.5%), magnesium sulfate (MgSO4, 4.6%), calcium channel blockers (3.8%), betamimetics other than ritodrine (1.9%), prostaglandin synthase inhibitors (0.5%), and nitrates (0.1%). Barring those using calcium channel blockers and combination therapy, the use of MgSO4 (aHR: 1.43, P = .001), betamimetics other than ritodrine (aHR: 1.71, P < .001), prostaglandin synthase inhibitors (aHR: 2.67, P < .001) and nitrates (aHR: 3.30, P = .001) was associated with higher risks of postoperative hemorrhage compared with ritodrine. In conclusion, CD women with preterm labor diagnosis using tocolytic agents exhibit an increased risk of postoperative hemorrhage and that this risk varies with the use of different tocolytic agents.

Maternal pulmonary edema after 46 h of ritodrine hydrochloride administration: A case report

Introduction

Ritodrine hydrochloride is still widely used as a tocolytic agent in Japan, but it can cause maternal pulmonary edema, which may paradoxically induce preterm birth. Here we present a case of severe pulmonary edema due to <48 h of ritodrine administration.

Case

A 46-year-old woman was diagnosed with threatened preterm labor (TPL) and placenta previa at 26 weeks of gestation. She had mild uterine contractions and genital bleeding. Ritodrine hydrochloride, magnesium sulfate, and betamethasone were administered. She developed dyspnea 46 h after starting ritodrine administration. Chest X-ray showed pulmonary edema. Even after cessation of ritodrine, dyspnea did not lessen and there were regular uterine contractions with abdominal pain. Emergency caesarean section was performed. A female neonate was delivered and admitted to the neonatal intensive care unit. After surgery, maternal dyspnea decreased without any complications.

Discussion

Excessive use of ritodrine or its use in combination with other tocolytic agents can cause maternal pulmonary edema, even with <48 h of use. Adverse maternal side-effects and rebound uterine contractions due to cessation of ritodrine may paradoxically trigger preterm birth. Strict patient selection for tocolytic therapy is essential and ritodrine requires caution because of its potential side-effects.

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Ritodrine hydrochloride is still widely used as a tocolytic agent in Japan.

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Ritodrine can cause maternal pulmonary edema, even with <48 h of administration.

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Strict patient selection for tocolysis is essential.

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Ritodrine requires caution because of potential side effects.

Efficacy of allylestrenol combined with ritodrine on threatened premature labor and its influence on inflammatory factors in peripheral blood

Efficacy of allylestrenol combined with ritodrine on threatened premature labor (TPTL) and its influence on inflammatory factors in peripheral blood were investigated. A total of 206 cases of TPTL patients from 2014 to 2016 were collected in Zhongshan Hospital Affiliated to Fudan University, and 106 cases were treated with allylestrenol combined with ritodrine as a research group and 100 cases were treated with allylestrenol combined with magnesium sulfate as a control group. General information of patients was collected, and changes in the expression levels of IL-17, IL-10 and IL-6 were detected by enzyme-linked immunosorbent assay. Prolonged pregnancy time, success rate of fetal protection and average delivery time of patients were recorded. The adverse pregnancy conditions were compared, including the Apgar score of newborns, birth weight and adverse conditions, and postpartum hemorrhage volume and postpartum hospital stays in the two groups were recorded. Prolonged pregnancy time, success rate of fetal protection and average delivery time in the research group were significantly higher than those in the control group (P<0.05). After treatment, the levels of IL-17, IL-10 and IL-6 in serum of the two groups were significantly lower than those before treatment (P<0.05), and were significantly lower in the research group than in the control group (P<0.05). The average neonatal weight and Apgar score in the research group were significantly better than those in the control group (P<0.05). Postpartum hemorrhage, postpartum hospital stays and incidence rate of toxic side effects, neonatal death, malformation and asphyxia in the research group were significantly lower than those in the control group (P<0.05). Allylestrenol combined with ritodrine can significantly reduce the expression levels of IL-17, IL-10 and IL-6 in TPTL, reduce adverse pregnancy conditions, prolong gestational weeks, and has higher safety and better application value.

Relaxing effects of clenbuterol, ritodrine, salbutamol and fenoterol on the contractions of horse isolated bronchi induced by different stimuli

β₂-adrenoceptor agonists are considered the most effective drugs to counteract bronchoconstriction in horses with asthma, but only clenbuterol is commonly employed in clinical practice. We evaluated the effects of different selective β₂ agonists: clenbuterol, ritodrine, salbutamol, and fenoterol on the contractions of isolated bronchial muscle of horses induced by electrical field stimulation (EFS), carbachol, histamine, and KCl. All β₂ agonists reduced the amplitude of contraction induced by the different stimuli but with variable efficacy and potency. Fenoterol and salbutamol were more effective than clenbuterol in relaxing the bronchial contractions induced by EFS and histamine, and were able to completely abolish carbachol-induced contractions, unlike clenbuterol and ritodrine. The respective potency values (pEC₅₀) of clenbuterol, ritodrine, salbutamol, and fenoterol were 7.74 ± 0.20, 7.77 ± 0.17, 7.30 ± 0.23, 8.01 ± 0.13, for EFS-induced contractions; 8.39 ± 0.26, 5.49 ± 0.28, 6.63 ± 0.14, 7.68 ± 0.11, for carbachol-induced contraction; 7.39 ± 0.27, 7.04 ± 0.28, 6.45 ± 0.34, 7.34 ± 0.22, for histamine-induced contraction; 7.15 ± 0.06, 6.07 ± 0.20, 6.48 ± 0.14, 6.70 ± 0.18, for KCl-induced contraction. Salbutamol and fenoterol showed a higher efficacy than clenbuterol in relaxing horse bronchial muscle pre-contracted by most stimuli. Clenbuterol displayed a good potency but a rather low efficacy, and this may be due to its partial agonist nature; ritodrine showed lower or not significantly different efficacy and potency compared to the other agonists. An evaluation of the clinical efficacy by fenoterol and salbutamol in horses with asthma could be of great interest to assess if they could represent more effective bronchodilators compared to clenbuterol.

Electroconvulsive Therapy in Depression: Current Practice and Future Direction

The current practice of electroconvulsive therapy (ECT) has evolved over several decades with the implementation of safer equipment and advancement of techniques. In addition, modifications in the delivery of ECT, such as the utilization of brief and ultrabrief pulse widths and individualization of treatment parameters, have improved the safety of ECT without sacrificing efficacy. This article aims to provide psychiatrists with a balanced, in-depth look into the recent advances in ECT technique as well as the evidence of ECT for managing depression in special populations and patients with comorbid medical problems.