OXT and pulmonary arterial hypertension: Administration of oxytocin is the mainstay of treatment for controlling PPH due to uterine atony and is usually commenced simultaneously with uterine massage.11 Optimal oxytocin dosage and route of administration during uterine atony are important to treat PPH and minimise side effects: intravenous (IV) 10-40 IU/500-1000 mL of lactated Ringer’s solution or intramuscular (IM) 5-10 IU for up to 4 doses.