(22.01) Propylthiouracil Retention Enema: Easy to Prepare, Well Absorbed, and Effective Treatment of Thyrotoxicosis in a Patient with Gastric Outlet Obstruction

In the United States, propylthiouracil (PTU) and methimazole are only commercially available in oral preparations. In certain patients, administration of these drugs by a non- oral route may be necessary. We describe a thyrotoxic patient with a gastric outlet obstruction who was successfully treated with PTU retention enemas.


Case(s) Description :

A 50-year-old female with peptic ulcer disease and hyperthyroidism presented with 2 days of epigastric pain, non-bloody emesis, and anorexia. A CT abdomen with contrast revealed a markedly distended stomach with thickening of the pylorus. Esophagogastroduodenoscopy was performed and revealed bleeding gastric ulcers and pyloric stenosis with inability to pass the scope to the duodenum. The patient was made strict nothing by mouth (NPO) ahead of planned antrectomy. On the fourth day of hospitalization, the patient became persistently tachycardic in spite of intravenous (IV) fluid resuscitation. On physical exam, she was afebrile, blood pressure was 105/75 mmHg, heart rate was 120 bpm, and her abdomen was distended and tender to palpation. On laboratory investigation TSH < 0.01 uIU/mL, free T4 1.83 ng/dL, total T3 190 ng/dL, free T3 4.1 pg/mL, consistent with thyrotoxicosis. Due to strict NPO status, the patient was started on IV propranolol 2 mg every 6 hours and a PTU retention enema 200 mg every 8 hours. Within 3 days of treatment, thyroid function and heart rate improved, and the patient underwent antrectomy. She was discharged on oral methimazole 10 mg daily and oral propranolol 20 mg every 8 hours.


Discussion :

This case describes an alternative administration of PTU in a patient with thyrotoxicosis. Multiple case reports have described thioanamide administration in the form of an IV solution or suppository. However, we discovered that preparation of these formulations can pose technical challenges for some pharmacies. Our inpatient pharmacy did not have the protocol nor materials to prepare either formulation and the patient was unable to afford PTU suppositories from a local compound pharmacy. Retention enemas can be easily prepared by a pharmacy or a nurse, have good rectal absorption and similar pharmacokinetics to oral thionamides, and are well tolerated by patients with minimal adverse events.