Daily Tadalafil and Gastric Emptying Time in Diabetic Gastroparesis

Inclusion Criteria:

- Type 1 diabetes diagnosis

- Age 18 - 65 years (inclusive)

- Hemoglobin A1c ≤ 10.5% within the last 4 months

- Diagnosis of gastroparesis, or symptoms consistent with gastroparesis (early satiety,
chronic intermittent nausea or vomiting with food intake)

- Patient has gastroparesis confirmed on screening study

- A female patient is eligible to participate if she is of: Non-childbearing potential
defined as pre-menopausal females with a documented tubal ligation or hysterectomy;
or postmenopausal defined as 12 months of spontaneous amenorrhea, or child-bearing
potential with negative serum hCG prior to each gastric emptying study.

Exclusion Criteria:

- Active nitrate use (e.g. Cialis, Viagra, Levitra, nitroglycerin, Isordil, Imdur, amyl
nitrate/poppers)

- Fasting fingerstick glucose > 250 mg/dL

- History of abdominal surgery including gastric banding procedure

- Patient is on chronic parenteral feeding

- Patient has a history of eating disorders (anorexia nervosa, binge eating, bulimia)

- Regular opiate use

- Recent (last 6 weeks) history of poor control of diabetes e.g. hypoglycemia requiring
medical intervention, diabetic ketoacidosis, admission for control diabetes or
complications of diabetes

- Acute severe gastroenteritis

- The patient has participated in another clinical trial in the last 30 days.

- Use of medications potentially influencing upper gastrointestinal motility or
appetite within one week of the study [e.g., prokinetic drugs, macrolide antibiotics
(erythromycin), GLP-1 mimetics/analog, amylin analog]

- History or presence of clinically significant gastro-intestinal, hepatic or renal
disease or other condition that would in the opinion of the investigator make the
subject unsuitable for inclusion in this clinical study.

- Chronic angina or NYHA class III or IV CHF

- Concurrent use of ketoconazole or itraconazole

- History of severe vision loss, retinitis pigmentosa, or non-arteritic anterior
ischemic optic neuropathy (NAION)

- History of CVA

- Pregnant females as determined by positive serum hCG test

- Lactating females

- Uncontrolled hypertension (SBP > 160 or DBP > 100)

- Hypotension (SBP < 90 or DBP < 60)

- Other major medical conditions: priapism, sickle cell anemia, multiple myeloma,
leukemia, active cancer diagnosis, HIV/AIDS, alcoholism, or bleeding diathesis.

- Intolerance to active or inactive ingredients of Cialis, or intolerance to other
PDE-5 inhibitors.