Atosiban

Registered South African indications: 

• Pre-term labour

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Gestational age below 24 or over 33 completed weeks
• Premature rupture of the membranes > 30 weeks of gestation
• Abnormal foetal heart rate
• Antepartum uterine haemorrhage requiring immediate delivery
• Eclampsia and severe pre-eclampsia requiring delivery
• Intrauterine foetal death
• Suspected intrauterine infection
• Placenta praevia
• Abruptio placenta
• Any other conditions of the mother or foetus, in which continuation of pregnancy is hazardous

Cautions

• Pregnancy
• Breastfeeding
• Hepatic impairment
• Suspected premature rupture of membranes
• Multiple pregnancies 
• Gestational age between 24 and 27 weeks
• Multiple re-treatments
• Intrauterine growth restriction 

Forms avail. in SA and covered in this monograph: inj

To delay imminent pre-term birth in pregnant women with:
- A gestational age from 26 completed weeks until 33 completed weeks
- Regular uterine contractions of at least 30 seconds duration at a rate of
 ≥ 4 per 30 minutes
- A cervical dilation of 1 to 3cm (0-3cm for nulliparas) and effacement of  ≥ 50%;
- A foetus without signs of foetal distress

• IV: Initial: 6.75mg, bolus; Then: 300μg/min, as an infusion over 3hrs; Then: 100μg/min, as an infusion over 45hrs; Max: 330mg/course

Intravenous therapy using the initial bolus injection of 7.5mg/ml solution for injection should be started as soon as possible after diagnosis of pre-term labour

In the case of persistence of uterine contractions during treatment an alternative therapy should be considered

Not established for use in children

Pregnancy

• Caution
• Atosiban should only be used when pre-term labour has been diagnosed between 24 and 33 completed weeks of gestation

Breastfeeding

• Caution; not recommended
• If during pregnancy the woman is already breastfeeding an earlier child, then breastfeeding should be discontinued during treatment with atosiban, since the release of oxytocin during breastfeeding may augment uterine contractility, and may counteract the effect of tocolytic therapy. In atosiban clinical trials no effects were observed on breastfeeding. Small amounts of atosiban have been shown to pass from plasma into the breast milk of breastfeeding women

Renal Impairment

• No dose adjustment recommended

Hepatic Impairment

• Caution; no dose adjustment recommended

Elderly        

• Not indicated for use in geriatric patients

Porphyria Information

• Probably not porphyrinogenic (PNP)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Insomnia
• Headache
• Dizziness

Cardiovascular Disorders

• Tachycardia
• Hypotension
• Hot flush

Gastrointestinal Disorders

• Nausea and vomiting

Genitourinary Disorders

• Uterine haemorrhage
• Uterine atony

Endocrine and Metabolic Disorders

• Hyperglycaemia

Skin and Subcutaneous Tissue Disorders

• Pruritis
• Rash
• Injection site reactions

Immune, Blood and Lymphatic System Disorders

• Allergic reaction
• Pyrexia

Tocolytic agents

• Fetal heart rate 
• Uterine contractions 

• In case a 're-treatment' with atosiban is needed, it should also commence with a bolus injection of atosiban 6.75 mg/0.9 ml, solution for injection followed by infusion with atosiban 37.5 mg/5 ml, concentrate for solution for infusion

Atosiban is a synthetic peptide which is a competitive antagonist of human oxytocin at receptor level. In rats and guinea pigs, atosiban was shown to bind to oxytocin receptors which decreased the frequency of contractions and the tone of the uterine musculature, resulting in a suppression of uterine contractions. Atosiban was also shown to bind to the vasopressin receptor, thus inhibiting the effect of vasopressin.

Injection (per ml) 7.5mg

• Tractocile solution for injection (Ferring) originator
• Tractocile concentrate for solution for infusion (Ferring) originator