Pulmonary hypertension is defined by 25 mmHg pressure at rest, and 35 mmHg pressure at exercise, in the pulmonary arteries. Hypertension either primary or secondary. The exact prevalence of all types of pulmonary hypertension is not yet known. We present a case of a 58-year-old female patient suffering from CREST syndrome, Raynaud's syndrome, esophageal motility impairment, and severe pulmonary hypertension who had previously obtained a specially developed implantable pump, named Lenus Pro(®), to facilitate continuous parenteral treatment of pulmonary arterial hypertension with treprostinil. Treprostinil is a prostanoid derivative with very stable physiochemical properties which allows subcutaneous treatment of pulmonary arterial hypertension in the outpatient. Treprostinil is normally dosed individually in a range of 0.6 to 50 ng/kg/minute. In the underlying case, a dose of more than 100 mg given over 1 minute is equivalent to a 1000 fold overdose. The patient's critical condition required installment of a central venous access, full monitoring, sedation, oxygen nasal tube, fluid balance, and parenteral nutrition. The patient could be hemodynamically stabilized within 24 hours after the overdose. After 6 days of recovery, the patient left the hospital with no remaining health impairment.