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Biological & Pharmaceutical Bulletin 2015Buccal tablets of ritodrine (RD) hydrochloride (HCl), called RD-HCl, were prepared using the direct compression method with alginate (AL), lactose (LC), magnesium...
Buccal tablets of ritodrine (RD) hydrochloride (HCl), called RD-HCl, were prepared using the direct compression method with alginate (AL), lactose (LC), magnesium stearate (ST), and microcrystalline cellulose (MC) as excipients. The tablets were evaluated based on hardness, and tablets weighing 80 mg and with hardness of greater than 30 N were chosen as appropriate ones. As a result, tablets composed of RD-HCl (4 mg)/LC (38.5 mg)/ST (0.5 mg)/MC (37 mg) and RD-HCl (4 mg)/AL(7 mg)/LC (28.5 mg)/ST (0.5 mg)/MC (37 mg), called D9 and D10, respectively, were selected. These tablets were further evaluated based on in vitro dissolution and in vivo absorption studies in rats. D9 rapidly released RD, achieved an effective plasma concentration from 15 min to 7 h after its buccal administration, and did not exceed the toxic plasma level of 80 ng/mL. D10 gradually released RD, and maintained an effective concentration from 1 h to 7 h after its buccal administration, without exceeding the toxic plasma level. The absorption was more prolonged in D10 than D9. Their in vivo release was considered to be caused gradually from the amount of RD remaining in the oral cavity at 7 h, in particular D10. The superior retention of D10 in plasma and oral cavity appeared to be related to its higher mucoadhesive properties. Although these results were obtained using rats, they suggest that the chosen tablets should have adequate characteristics from the viewpoints of plasma levels.
Topics: Administration, Buccal; Alginates; Animals; Cellulose; Chemistry, Pharmaceutical; Drug Liberation; Excipients; Glucuronic Acid; Hardness; Hexuronic Acids; Intestinal Absorption; Lactose; Male; Mouth; Rats, Wistar; Ritodrine; Solubility; Stearic Acids; Tablets
PubMed: 26027834
DOI: 10.1248/bpb.b14-00833 -
Journal of the Formosan Medical... Jun 2009Management of preterm labor involves the use of tocolytic drugs to inhibit preterm uterine contractions. This study compared the efficacy and safety of intravenous... (Comparative Study)
Comparative Study Randomized Controlled Trial
BACKGROUND/PURPOSE
Management of preterm labor involves the use of tocolytic drugs to inhibit preterm uterine contractions. This study compared the efficacy and safety of intravenous administration of atosiban and ritodrine in the treatment of spontaneous preterm labor.
METHODS
A randomized study was conducted in pregnant women of Chinese origin in Taiwan with threatened preterm delivery. Patients were randomized to receive either atosiban (n = 23) or ritodrine (n = 22). Tocolytic efficacy of the drug was assessed as the proportion of women who did not deliver and did not need alternative tocolytic treatment at 7 days after therapy initiation. Safety of the drugs was assessed as the number of adverse events or neonatal morbidity.
RESULTS
The number of women who did not deliver and did not require alternative tocolytic therapy at 7 days was similar between the atosiban and ritodrine groups. There were no serious adverse events, but maternal cardiovascular adverse events, particularly tachycardia, occurred significantly more in women treated with ritodrine (0% atosiban vs. 18.18% ritodrine, p < 0.05). There was no difference in neonatal or infant outcome between the two drugs.
CONCLUSION
The present study showed similar effectiveness between atosiban and ritodrine, while tachycardia occurred more frequently in women treated with ritodrine. These results indicate that atosiban is an effective tocolytic drug without the conventional cardiovascular side effects often seen with beta-agonist treatment.
Topics: Adrenergic beta-Agonists; Adult; Female; Humans; Obstetric Labor, Premature; Oxytocin; Pregnancy; Tocolytic Agents; Vasotocin
PubMed: 19515630
DOI: 10.1016/S0929-6646(09)60097-8 -
Acta Obstetricia Et Gynecologica... Sep 2001To evaluate the effect of antenatal tocolytic administration of magnesium sulphate and ritodrine on the cerebral blood flow velocity and on the cerebral vascular...
BACKGROUND
To evaluate the effect of antenatal tocolytic administration of magnesium sulphate and ritodrine on the cerebral blood flow velocity and on the cerebral vascular resistance of preterm newborns in the first hours of life.
METHODS
Cerebral blood flow velocity, resistance index and relative vascular resistance were studied in 27 preterm infants (<34 weeks gestation) with antenatal exposure to maternal magnesium sulphate treatment and in 27 preterm infants (<34 weeks gestation) with antenatal exposure to maternal ritodrine treatment. Both antenatal magnesium sulphate or ritodrine were used for tocolysis. Cerebral blood flow was measured, using Doppler ultrasonography, in the anterior cerebral artery, in the left middle cerebral artery and in the right middle cerebral artery.
RESULTS
We did not find any significant difference in the blood flow velocity, resistance index or relative vascular resistance in the three cerebral arteries between the two treatment groups.
CONCLUSIONS
Our study shows that maternal antenatal administration of magnesium sulphate to delay preterm delivery, compared to antenatal administration of ritodrine, does not induce any significant differences either in cerebral blood flow velocity or in cerebral vascular resistance of preterm infants in the first hours of life.
Topics: Blood Flow Velocity; Cerebrovascular Circulation; Female; Humans; Infant, Newborn; Infant, Premature; Magnesium Sulfate; Ritodrine; Tocolytic Agents; Ultrasonography, Doppler; Vascular Resistance
PubMed: 11531632
DOI: 10.1034/j.1600-0412.2001.080009818.x -
British Journal of Pharmacology Sep 19931. Acute psychological stress, which could be related to the release of a large amount of catecholamines, may cause oesophageal motility disorders. Therefore, the aim of...
1. Acute psychological stress, which could be related to the release of a large amount of catecholamines, may cause oesophageal motility disorders. Therefore, the aim of our study was to elucidate the influence of adrenoceptor agonists on the striated muscle portion of the oesophagus by use of isolated strips from dogs. 2. Contractions were evoked in isolated striated muscle strips by electrical field stimulation (1 pulse min-1, 1 ms/pulse, submaximal voltage). The effects induced by administration of adrenoceptor agonists alone or in the presence of antagonists were tested to determine the nature of the adrenoceptors on this muscle preparation. 3. The administration of both the natural adrenoceptor agonists, adrenaline and noradrenaline, and the synthetic beta-adrenoceptor agonists, isoprenaline (beta 1 + beta 2), dobutamine (beta 1) or ritodrine (beta 2), enhanced the amplitude of the contractions induced by electrical stimulation in a concentration-dependent manner. The maximum responses were 82.6 (adrenaline), 66.2 (noradrenaline), 86.2 (isoprenaline), 34.6 (dobutamine) and 80.8% (ritodrine). The EC20 values obtained were respectively 2 nM, 0.2 microM, 0.91 nM, 3 microM and 80 nM. The administration of the alpha 1-adrenoceptor agonist, phenylephrine, also enhanced the contractile response in a concentration-dependent manner (EC20 value = 0.3 microM) and the maximum response was 64.6%, but the administration of the alpha 2-adrenoceptor agonist, clonidine, did not influence the contractile response. These data suggest the involvement of beta 2- and possibly alpha 1-adrenoceptors in the responses of these adrenoceptor agonists. 4 The selective P2-adrenoceptor antagonist ICI 118551 (3-100nM) shifted the concentration-effect curves for noradrenaline, phenylephrine and ritodrine to the right in a concentration-dependent manner.ICI 118551 (3 nM) also shifted the concentration-effect curves for adrenaline and isoprenaline to the right, but increasing the concentration of ICI 118551 did not cause any further antagonist activity until a concentration of 100 nM, when a further rightward shift was obtained.5. The selective alpha 1-adrenoceptor antagonist, prazosin (30-300 nM), did not affect the increased contractile responses induced by adrenaline, noradrenaline, phenylephrine, isoprenaline or ritodrine.6. In conclusion, it appears that beta2-adrenoceptors are present in the striated muscle portion of the canine oesophagus, where they mediate an enhancement of contractile responses evoked by electrical stimulation. The alpha l-agonist, phenylephrine, appears to interact with beta2-adrenoceptors on this preparation.beta 3-Adrenoceptors have already been demonstrated in smooth muscle from various parts of the gastrointestinal tract, and our study does not exclude the possibility that there is an additional population of beta 3-receptors in the canine striated muscle part of the oesophagus.
Topics: Adrenergic alpha-Agonists; Adrenergic beta-Agonists; Adrenergic beta-Antagonists; Animals; Dogs; Esophagus; Female; In Vitro Techniques; Isometric Contraction; Isoproterenol; Male; Muscle, Smooth; Norepinephrine; Phenylephrine; Prazosin; Propanolamines; Receptors, Adrenergic, alpha-1; Receptors, Adrenergic, alpha-2; Receptors, Adrenergic, beta-1; Receptors, Adrenergic, beta-2; Ritodrine
PubMed: 8106105
DOI: 10.1111/j.1476-5381.1993.tb13808.x -
The Journal of International Medical... 2012This study aimed to develop a model for predicting the outcome and evaluating the treatment of patients with threatened of preterm labour.
OBJECTIVE
This study aimed to develop a model for predicting the outcome and evaluating the treatment of patients with threatened of preterm labour.
METHODS
Clinical data from 236 patients at <32 weeks gestation who were in preterm labour were analysed to develop a discriminant function using multiple logistic regression to identify significant risk factors. The function was validated retrospectively in a further 501 patients and prospectively in 63 patients with premature labour.
RESULTS
Factors that increased the risk of preterm birth were premature rupture of the membranes, intrauterine infection, dilatation of the cervix and uterine bleeding. Factors that decreased the risk of preterm birth were hospital admission after 28 weeks of gestation and intravenous administration of ritodrine. The predictive accuracy of the function was 75.4% in the 236 patients analysed, 84.8% in the further 501 retrospectively studied patients and 85.7% in the prospective group.
CONCLUSIONS
The discriminant function described was clinically useful for predicting the outcome of threatened preterm labour before initiating treatment and for determining the medical care of patients, including maternal transfer to a high-level perinatal care centre.
Topics: Adult; Discriminant Analysis; Female; Humans; Logistic Models; Models, Biological; Obstetric Labor, Premature; Odds Ratio; Pregnancy; Prospective Studies; Retrospective Studies; Risk Factors; Ritodrine; Sensitivity and Specificity; Tocolysis; Tocolytic Agents; Treatment Outcome; Young Adult
PubMed: 22971497
DOI: 10.1177/147323001204000424 -
The Journal of Physiological Sciences :... Nov 2017We aimed to prospectively examine β-adrenoceptor-mediated uterine contractility in women suffering from gynecological malignancies. Myometrial specimens were obtained...
We aimed to prospectively examine β-adrenoceptor-mediated uterine contractility in women suffering from gynecological malignancies. Myometrial specimens were obtained from non-pregnant women undergoing hysterectomy for benign gynecological disorders, and ovarian, endometrial, synchronous ovarian-endometrial, and cervical cancer. Contractions of myometrial strips in an organ bath before and after cumulative dosages of β- and β-adrenoceptor agonists with preincubation of propranolol, SR 59230A, and butoxamine were studied. All agonists induced a dose-dependent attenuation for uterine contractility in endometrial or cervical cancer, similar to that observed in the reference group. Contradictory effects were observed for ovarian cancer alone or in combination with endometrial cancer. CL 316243 or ritodrine abolished the relaxation, whereas BRL 37344 increased the uterine contractility in ovarian cancer. Moreover, β-adrenoceptor antagonists caused varied effects for β- or β-adrenoceptor agonists. Our experiments demonstrate that ovarian cancer, alone or as synchronous ovarian-endometrial cancer, substantially alters uterine contractility in response to β-adrenoceptor agonists.
Topics: Adrenergic beta-3 Receptor Agonists; Adrenergic beta-Agonists; Adult; Aged; Aged, 80 and over; Dioxoles; Endometrial Neoplasms; Ethanolamines; Female; Humans; Middle Aged; Ovarian Neoplasms; Receptors, Adrenergic, beta; Ritodrine; Uterine Contraction
PubMed: 27838886
DOI: 10.1007/s12576-016-0500-1 -
Iranian Journal of Reproductive Medicine 2011Pregnancy rate with IVF cycle is almost 22%. Many investigations perform to increase this rate in IVF. Various factors affect the result of IVF cycles. One of these...
BACKGROUND
Pregnancy rate with IVF cycle is almost 22%. Many investigations perform to increase this rate in IVF. Various factors affect the result of IVF cycles. One of these factors could be uterine contractions that expel transferred embryo. Ritodrine is a beta mimetic agent that can block and decrease uterine contractions.
OBJECTIVE
The objective of this study was to determine ritodrine effectiveness for increasing the implantation rate in IVF cycles, and its probable mechanisms in decreasing uterine contractions as well.
MATERIALS AND METHODS
A total of 100 patients of IVF-ET cycles were divided randomly in two groups in a university hospital, Hamadan, Iran. The case group were prescribed ritodrine 10 mg / bid orally after oocyte retrieval until 10 days. The control group didn't received ridotrine.
RESULTS
In ritodrine group 14% of patients and in control group 16% had positive β-hCG test (p-value>0.5).
CONCLUSION
Ritodrine did not improve the implantation rate in IVF-ET cycles.
PubMed: 26396570
DOI: No ID Found -
Taiwanese Journal of Obstetrics &... Dec 2010Pregnancies with extremely preterm premature rupture of membranes (EPPROM), especially before 20 weeks of gestation, are usually considered to be a termination of... (Review)
Review
OBJECTIVE
Pregnancies with extremely preterm premature rupture of membranes (EPPROM), especially before 20 weeks of gestation, are usually considered to be a termination of pregnancy. By improvement of obstetric and neonatal care, we can prolong the pregnancy across the threshold of survival by aggressive tocolysis.
CASE REPORT
Using intrauterine insemination, a 32-year-old woman became pregnant with twins (first pregnancy). Threatened abortion occured since 9 weeks of gestation and EPPROM of the upper twin was noted at 18 weeks. Massive vaginal bleeding and vigorous uterine contractions occurred at 22 weeks. Poor control of preterm labor occurred using ritodrine and MgSO(4). Atosiban was applied to calm uterine activities. After discontinuation of atosiban at 30 weeks, the uterine contractions became severe again and an emergency cesarean section was performed to deliver two live, premature babies weighing 1,518 g and 830 g, respectively. Twin A was healthy, weighing 2,030 g at 35 days after birth and subsequently discharged. The smaller twin B was dependent on continuous positive airway pressure and died of pulmonary infection 120 days after birth.
CONCLUSION
Comparing to other tocolytic agents, Atosiban has few side effects and assisted in prolonging a pregnancy involving twins that experienced EPPROM.
Topics: Adult; Female; Fetal Growth Retardation; Fetal Membranes, Premature Rupture; Gestational Age; Humans; Infant, Newborn; Infant, Premature; Magnesium Sulfate; Male; Pregnancy; Pregnancy, Multiple; Premature Birth; Reproductive Techniques, Assisted; Ritodrine; Tocolysis; Tocolytic Agents; Twins; Vasotocin
PubMed: 21199753
DOI: 10.1016/S1028-4559(10)60103-9 -
BMJ (Clinical Research Ed.) Nov 1988To compare the effects on fetal and maternal morbidity of routine active management of third stage of labour and expectant (physiological) management, in particular to... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
OBJECTIVE
To compare the effects on fetal and maternal morbidity of routine active management of third stage of labour and expectant (physiological) management, in particular to determine whether active management reduced incidence of postpartum haemorrhage.
DESIGN
Randomised trial of active versus physiological management. Women entered trial on admission to labour ward with allocation revealed just before vaginal delivery. Five months into trial high rate of postpartum haemorrhage in physiological group (16.5% v 3.8%) prompted modification of protocol to exclude more women and allow those allocated to physiological group who needed some active management to be switched to fully active management. Sample size of 3900 was planned, but even after protocol modification a planned interim analysis after first 1500 deliveries showed continuing high postpartum haemorrhage rate in physiological group and study was stopped.
SETTING
Maternity hospital.
PARTICIPANTS
Of 4709 women delivered from 1 January 1986 to 31 January 1987, 1695 were admitted to trial and allocated randomly to physiological (849) or active (846) management. Reasons for exclusion were: refusal, antepartum haemorrhage, cardiac disease, breech presentation, multiple pregnancy, intrauterine death, and, after May 1986, ritodrine given two hours before delivery, anticoagulant treatment, and any condition needing a particular management of third stage.
INTERVENTIONS
All but six women allocated to active management actually received it, having prophylactic oxytocic, cord clamping before placental delivery, and cord traction; whereas just under half those allocated to physiological management achieved it. A fifth of physiological group received prophylactic oxytocic, two fifths underwent cord traction and just over half clamping of the cord before placental delivery.
ENDPOINT
Reduction in incidence of postpartum haemorrhage from 7.5% under physiological management to 5.0% under active management.
MEASUREMENTS AND MAIN RESULTS
Incidence of postpartum haemorrhage was 5.9% in active management group and 17.9% in physiological group (odds ratio 3.13; 95% confidence interval 2.3 to 4.2), a contrast reflected in other indices of blood loss. In physiological group third stage was longer (median 15 min v 5 min) and more women needed therapeutic oxytocics (29.7% v 6.4%). Apgar scores at one and five minutes and incidence of neonatal respiratory problems were not significantly different between groups. Babies in physiological group weighed mean of 85 g more than those in active group. When women allocated to and receiving active management (840) were compared with those who actually received physiological management (403) active management still produced lower rate of postpartum haemorrhage (odds ratio 2.4;95% CI1.6 to 3.7).
CONCLUSIONS
Policy of active management practised in this trial reduces incidence of postpartum haemorrhage, shortens third stage, and results in reduced neonatal packed cell volume.
Topics: Breast Feeding; Clinical Trials as Topic; Constriction; Delivery, Obstetric; Female; Hematocrit; Humans; Infant, Newborn; Labor Stage, Third; Labor, Obstetric; Obstetric Labor Complications; Oxytocics; Postpartum Hemorrhage; Posture; Pregnancy; Pregnancy Outcome; Random Allocation; Time Factors; Umbilical Cord
PubMed: 3144366
DOI: 10.1136/bmj.297.6659.1295 -
Japanese Journal of Pharmacology Oct 2002This study was designed to elucidate the effects of meluadrine tartrate on oxytocin-induced uterine contraction and maternal hemodynamics in unanesthetized, chronically... (Comparative Study)
Comparative Study
Effects of meluadrine tartrate and ritodrine hydrochloride on oxytocin-induced uterine contraction, uterine arterial blood flow and maternal cardiovascular function in pregnant goats.
This study was designed to elucidate the effects of meluadrine tartrate on oxytocin-induced uterine contraction and maternal hemodynamics in unanesthetized, chronically instrumented pregnant goats. After the administration of meluadrine tartrate or ritodrine hydrochloride to pregnant goats, changes in heart rate (HR), arterial blood pressure (AOP), and arterial blood pH and gasses (P(O2) and P(CO2)) in the mother, as well as changes in intrauterine pressure (IUP) and uterine arterial blood flow (UBF), were measured. The escalating administration of meluadrine tartrate (0.03, 0.1, 0.3 and 1 micro g. kg(-)(1). min(-)(1)) or ritodrine hydrochloride (1, 3, 10 and 30 microg. kg(-)(1). min(-)(1)) to the maternal femoral vein caused a marked and similar inhibition in oxytocin-induced uterine contraction (a rise in IUP). By these escalating dosings, maternal HR was increased dose-dependently in both treatment groups; however, the degree of the HR increase in the meluadrine tartrate-treatment group was significantly less than that in the ritodrine hydrochloride-treatment group. Furthermore, the degree of the UBF decrease in the meluadrine tartrate-treatment group was significantly less than that in the ritodrine hydrochloride-treatment group. The present study suggests that meluadrine tartrate has a mild influence on the maternal cardiovascular function relative to the effects of ritodrine taking the potent efficacy on oxytocin-induced uterine contraction into account.
Topics: Adrenergic beta-Agonists; Animals; Blood Pressure; Carbon Dioxide; Cardiovascular System; Dose-Response Relationship, Drug; Female; Goats; Heart Rate; Hydrogen-Ion Concentration; Infusions, Intravenous; Oxygen; Oxytocin; Pregnancy; Regional Blood Flow; Ritodrine; Tartrates; Time Factors; Tocolytic Agents; Uterine Contraction; Uterus
PubMed: 12419879
DOI: 10.1254/jjp.90.107