Ritodrine


Generic Medicine Info
Indications and Dosage
Oral
Uncomplicated premature labour
Adult: Start oral therapy 30-60 mins before termination of IV infusion at 10 mg every 2 hr for 24 hr. Subsequently, 10-20 mg every 4-6 hr according to patient's response. Max oral dose 120 mg daily.

Parenteral
Uncomplicated premature labour
Adult: Given as IV infusion, initially 0.05 mg/min. Increase by 0.05 mg/min every 10 min until patient responds. Usual rate: 0.15-0.35 mg/min. As IM inj: 10 mg every 3-8 hr. Maintain for 12-48 hr after the contractions have stopped.
Contraindications
Antepartum haemorrhage, eclampsia and severe preeclampsia, intrauterine foetal death, cardiac disease. Threatened miscarriage, placenta praevia and cord compression.
Special Precautions
CV risk factors, concurrent steroids, hyperthyroidism, myocardial insufficiency, arrhythmias, hypertension, DM, bronchial asthma treated with beta-agonists, lactation. Monitor plasma glucose and potassium. Monitor maternal pulse throughout infusion; adjust rate to avoid maternal heart beat exceeding 140 beats/min. Monitor patient's hydration status to reduce risk of pulmonary oedema. Discontinue treatment if there are signs of pulmonary oedema.
Adverse Reactions
Tachycardia, palpitation, headache, nervousness, anxiety, nausea, vomiting.
Potentially Fatal: Rarely, anaphylaxis, arrhythmia, pulmonary oedema, hypokalaemia.
IV/Parenteral/PO: B
Overdosage
May lead to tachycardia, CNS stimulation, hypokalaemia and hyperglycaemia.
Drug Interactions
May enhance neuromuscular blockade produced by pancuronium and vecuronium.
Potentially Fatal: Potassium-depleting drugs may increase risk of hypokalaemia.
Action
Description: A selective β2-adrenoceptor agonist with its main action on the uterus, causing relaxation. It reduces the intensity and frequency of contractions. Heart rate is also increased while diastolic pressure is reduced. May cause bronchial relaxation but this is not clinically significant in its usage.
Pharmacokinetics:
Absorption: Rapid absorption from the GI tract (oral). Bioavailability: about 30% of an oral dose.
Distribution: Crosses the placenta.
Metabolism: Hepatic: By conjugation with glucuronic acid or sulfate.
Excretion: 70-90% of a dose is excreted in the urine within 10-12 hr.
MIMS Class
Drugs Acting on the Uterus
Disclaimer: This information is independently developed by MIMS based on Ritodrine from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by MIMS.com
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