Indications
Ritodrine is used in hospital to delay preterm labour (labour that starts before 37 weeks of pregnancy) in carefully selected women, usually to allow time for steroid injections that help the baby’s lungs mature or for transfer to a specialist unit. It is used only by obstetric specialists.
How It Works
Ritodrine stimulates beta-2 receptors in the muscle of the womb (uterus). This relaxes the muscle and reduces the strength and frequency of contractions, which can delay delivery for a short time.
Dosage and Administration
Ritodrine is given by a doctor or nurse in hospital, usually as a carefully controlled drip into a vein, with close monitoring of the mother’s heart rate, blood pressure, fluid balance and the baby’s heartbeat. The dose is as prescribed and is adjusted according to the response and side effects. Tablets, where used, are also taken only as prescribed.
Interactions
Steroids such as Dexamethasone or Betamethasone, given to mature the baby’s lungs, can increase the risk of fluid on the lungs when used together. Beta blockers block its effect. Anaesthetics, other heart stimulants, diuretics, Magnesium Sulphate and some antidepressants can increase heart and blood pressure effects or lower potassium. The hospital team will check all medicines given.
Contraindications
Not used when continuing the pregnancy is dangerous for mother or baby, for example in heavy bleeding, severe pre-eclampsia or eclampsia, infection in the womb, death of the baby in the womb, or serious heart disease, uncontrolled high blood pressure, overactive thyroid or poorly controlled diabetes in the mother. Not used before about 22 weeks or after 37 weeks, or in allergy to Ritodrine.
Side Effects
Common effects include a fast heartbeat, palpitations, shaking, nervousness, flushing, headache, nausea, vomiting, high blood sugar and low potassium. The baby’s heart rate may also rise.
Serious effects include fluid on the lungs (pulmonary oedema), chest pain, irregular heartbeat and heart damage. Tell the nurse or doctor at once if you feel short of breath, have chest pain or tightness, or a very fast or irregular heartbeat.
Pregnancy and Lactation
It is used only in pregnancy, under specialist hospital care, when the benefit of delaying birth is judged greater than the risks. It is not used during breastfeeding.
Precautions and Warnings
Many countries now limit its use because of serious heart and lung side effects, and other medicines are often preferred. Fluids, heart rate, blood pressure, blood sugar and potassium must be checked closely. Extra care is needed in twin pregnancy, diabetes, and any heart condition.
Overdose
Too much causes a very fast heartbeat, low blood pressure, shaking, chest pain, high blood sugar and breathlessness. The infusion is stopped and the hospital team gives supportive treatment.
Therapeutic Class
Beta-2 agonist tocolytic (medicine to relax the uterus).
Storage
Store as directed on the pack, usually below 30°C, away from light and out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.