Written by Vanessa Jones, B.A  | 
Medically Reviewed by Dr. Sunil Shroff, MBBS, MS, FRCS (UK), D. Urol (Lond) on Aug 28, 2014

Clinical Trials - Phase I

In Phase I trials the new / experimental drug or treatment is tried out on a small group (20-80) of healthy human subjects for the first time , after it has been well tested in lab and animal studies. This initial phase of testing typically takes several months.

The main purpose of this phase is to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of the new treatment or the new drug on humans and the side effects associated with increasing doses and also to determine what dosages patients can take without causing them harm.

When compared to the later phases of the clinical trial, phase I studies, carry significant risks, however it is a very important phase as the information gained in this phase of the study, about a potential treatment's effects in patients and any early findings on its effectiveness are critical for the design of later-phase studies.

Phase -I drug trials are mostly conducted in inpatient clinics where the participant is continuously monitored by medical staff.

Phase -I trials can be further divided into two types:

  • Single Ascending Dose studies ( SAD )
  • Multiple Ascending Dose studies ( MAD )


jagan1206 Wednesday, January 7, 2015

can any one give me different names given to different phases in clinical studies?

infoalcpl Friday, October 29, 2010

My colleagues and I have just concluded one of India's most in-depth studies on "Clinical Trials in India". We have looked at various areas such as:
- Market Trends
- Growth Drivers
- Regulatory Bodies and Framework
- Major Players.
We interviewed over 200 individuals and firms to collect the data in what we believe is one of the most detailed study on the subject in India.

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