Ritodrine Hydrochloride Injection

Pharmacological studies have shown that ritodrine hydrochloride acts on the beta 2 receptors of uterine smooth muscle, thereby inhibiting the contraction frequency and intensity of uterine smooth muscle. It is an effective drug for oral, intramuscular and intravenous injection to prolong pregnancy and prevent premature birth. Carcinogenicity, teratogenicity, and effects on fertility: Rats were orally administered ritodrine hydrochloride at 1 mg/kg, 10 mg/kg and 150 mg/kg daily for 82 weeks. Benign and malignant tumors were found in all dose groups. Since there was no significant difference between the treatment group and the control group and there was no dose-related trend, it was inferred that there was no sign of carcinogenicity. In the reproduction study of rats and rabbits, the results showed that ritodrine hydrochloride had no effect on fertility.

Ritodrine Hydrochloride

This product is a colorless to slightly yellow clear liquid.

Prevent premature birth after 20 weeks of pregnancy. The effectiveness and safety of this product when the cervical opening is greater than 4 cm or more than 80% open has not yet been established.

Diagnosed with premature delivery and suitable for this product, initially use intravenous drip followed by oral maintenance treatment, closely monitor uterine contraction and side effects to determine the best dosage. Intravenous drip: According to the situation of the pregnant woman, the frequency of uterine contraction, heart rate, blood pressure and fetal heart rate should be monitored frequently during drip. Take 2 vials of this product totaling 100 mg and dilute it with 500 ml of intravenous drip solution to a solution of 100 mg/500 ml (0.2 mg/ml). Keep the left side position during intravenous drip to reduce the risk of hypotension. Closely observe the drip rate, use a controllable infusion device or adjust the number of drops per minute. At the beginning, the drip rate should be controlled to a dose of 0.05 mg/min (5 drops/min, 20 drops/ml), and increase by 0.05 mg/min (increase 5 drops/min) every 10 minutes until the desired effect is achieved, usually maintained at 0.15 mg/min-0.35 mg/min (15-35 drops/min), and continue to infuse for at least 12-18 hours after uterine contractions stop.

The adverse reactions of this product are related to the b; sympathetic nerve action and can usually be controlled by adjusting the dose. Intravenous infusion often causes an increase in the heart rate of pregnant women and fetuses. For healthy pregnant women, the heart rate should be avoided to exceed 140 beats/minute. Appropriate reduction of the dose or cessation of infusion will quickly return to normal. Serious adverse reactions: pulmonary edema, pulmonary edema combined with heart failure, leukopenia, agranulocytosis, arrhythmia, in the case of multiple pregnancies, there are reports of arrhythmia turning into cardiac arrest immediately after the administration of anesthetics, rhabdomyolysis (muscle pain, weakness, CPK increase, increased myoglobin in blood and urine), neonatal intestinal occlusion, neonatal ventricular septal hypertrophy, low serum potassium caused by beta; 2 receptor agonists, shock, jaundice, Stenvens-Johnson syndrome. Other adverse reactions: Cardiovascular system: supraventricular tachycardia, palpitations, tachycardia, sometimes facial flushing, chest pain, dyspnea, rare electrocardiogram abnormalities (ST-T abnormalities), facial pain. Fetal tachycardia and arrhythmia. Liver: Sometimes there is damage to liver function (increase in GOT, GPT, etc.). Blood system: Rarely thrombocytopenia. Psychoneural system: Sometimes there is tremor, numbness, headache, heat in the extremities, weakness, rarely sweating, and dizziness. Digestive system: Sometimes there is nausea, vomiting, constipation, and swelling of the salivary glands with increased amylase. Allergies: Sometimes there is rash, itching, rarely erythema, and swelling. Administration site: Sometimes there is vascular pain and phlebitis. Others: Transient increase in blood sugar, increase in CPK, sometimes changes in urine sugar, fever, and rarely cold sweats. Pregnant women who have used b; sympathomimetic agents have symptoms of hypocalcemia, hypoglycemia, and intestinal obstruction in their babies, but these are rare.

This product is contraindicated for use in pregnant women who are less than 20 weeks pregnant. It is also contraindicated for use in situations where prolonged pregnancy poses a risk to the pregnant woman and the fetus, including: 1. Heavy bleeding before delivery for any reason, especially placenta previa and placental abruption. 2. Eclampsia and severe preeclampsia. 3. Fetal death in the womb. 4. Chorioamnionitis. 5. Pregnant women with heart disease and conditions that endanger heart function. 6. Pulmonary hypertension. 7. Pregnant women with hyperthyroidism. 8. Uncontrolled diabetes. 9. Severe hypertension. 10. Allergic to any ingredient in this product.

Precautions for children: Not applicable. Precautions for pregnancy and lactation: Teratogenic effects in pregnancy (pregnancy category B) According to reports, in reproduction studies with rats and rabbits, 1/9 (1 mg/kg), 1/3 (3 mg/kg) and 1 (9 mg/kg) times the maximum daily dose of human intravenous drip were given to animals (animals were given pills), and 5 and 50 times the maximum daily oral maintenance dose of human, that is, 10 and 100 mg/kg, were given to animals. The results showed that ritodrine hydrochloride had no effect on fertility and fetus. Single doses of 1, 3 and 9 mg/kg/day intravenously or 10 and 100 mg/kg/day were given to rats and rabbits at 6-15 days and 6-18 days of pregnancy, respectively, and there was no adverse effect on the fetus. Intravenous 1 and 8 mg/kg/day or oral 10 and 100 mg/kg/day were given to animals at 15-21 days of pregnancy, and there was no effect on the development of rat pups during the perinatal period and after birth. A slight increase in fetal weight was observed in rats. Oral administration does not affect fertility and reproductive behavior. A lethal dose given to pregnant rats will not cause immediate fetal death. There are no adequate and well-controlled studies on the effects of ritodrine on women before 20 weeks of pregnancy. Therefore, this drug should not be used in pregnant women before the 20th week of pregnancy. Studies that give ritodrine to pregnant women after the 20th week of pregnancy have shown that there is no increased risk of fetal malformations. Randomly selected and followed up a small number of children to 2 years old, showing no effects on growth, development or organ maturation. However, although clinical studies have not proven that permanent effects on the fetus come from ritodrine, this possibility cannot be ruled out. Therefore, ritodrine can only be used when the indication is clear. Some studies have shown that infants born before 36 weeks of pregnancy account for less than 10% of all births, but account for 75% of perinatal deaths and half of all infants with neurological disabilities. Relevant data show that infants born at any time before the entire gestational period are more likely to have neurological or other disabilities than infants born at or after the full gestational period. Ritodrine has been reported to be excreted in breast milk in rats; therefore, if the drug is administered before delivery, it is recommended to avoid breastfeeding immediately after delivery.

1 Avoid using it at the same time with beta-receptor agonists and inhibitors. 2 Simultaneous use of corticosteroids may lead to pulmonary edema. 3 The following drugs used at the same time may aggravate the cardiovascular effects, especially arrhythmias or hypotension: ① magnesium sulfate ② diazoxide ③ pethidine ④ strong anesthetics. 4 Hypertension may occur in the presence of parasympathetic blockers such as atropine. 5 When used simultaneously with other parasympathetic amines, the cardiovascular effects are enhanced. But this can be avoided as long as there is enough time interval. Because 90% of ritodrine is excreted from the body within 24 hours of administration. 6 For anesthetics used in surgery, it should be considered that the effects on patients with hypotension may be enhanced.

Store at room temperature (preferably below 30°C).

5 ml: 50 mg

36 months