The study is an open-label, randomized,2-period, single dose, crossover study in 8 healthy male/female volunteers. Subjects will be randomized to the following sequences:

(A) Period 1: KT110 - wash-out period - Period 2: Alpress and Periactin marketed tablets ; Or (B) Period 1: Alpress and Periactin marketed tablets - wash-out period - Period 2: KT110

Inclusion Criteria:

• Healthy male/female subject
• Females of childbearing potential and male participant must agree to use an adequate and highly effective method of contraception
• Negative serum pregnancy test at screening for woman of childbearing potential only
• Non-smoker subject or smoker of not more than 5 cigarettes a day
• Body Mass Index (BMI) between 18.5 and 30 kg/m2 inclusive, at screening

Exclusion Criteria:

• Any contraindication to Prazosin or Cyproheptadine treatments;
• Frequent headaches and / or migraine, recurrent nausea and / or vomiting;
• Symptomatic hypotension whatever the decrease of blood pressure or asymptomatic postural hypotension defined by a decrease equal to or greater than 20 mmHg in systolic blood pressure (SBP) and a decrease equal to or greater than 10 mmHg in diastolic blood pressure (DBP) within two minutes of changing from supine to standing position;
• Blood donation (including as part of a clinical trial) in the 2 months before administration
• Any drug intake (except paracetamol or contraception) during the month prior to the first administration;
• History or presence of drug or alcohol abuse (alcohol consumption > 40 grams / day)
• Excessive consumption of beverages with xanthine bases (> 4 cups or glasses / day);
• Positive Hepatitis B surface (HBs) antigen or anti Hepatitis C Virus (HCV) antibody, or positive results for Human Immunodeficiency Virus (HIV) 1 or 2 tests
• Positive results of screening for drugs of abuse