Clinical pharmacology has been defined as "that discipline that teaches, does research, frames policy, gives information and advice about the actions and proper uses of medicines in humans and implements that knowledge in clinical practice". Clinical Pharmacology is inherently a translational discipline underpinned by the basic science of pharmacology, engaged in the experimental and observational study of the disposition and effects of drugs in humans, and committed to the translation of science into evidence-based therapeutics. It has a broad scope, from the discovery of new target molecules to the effects of drug usage in whole populations. The main aim of clinical pharmacology is to generate data for optimum use of drugs and the practice of 'evidence based medicine'. Clinical pharmacologists have medical and scientific training that enables them to evaluate evidence and produce new data through well-designed studies. Clinical pharmacologists must have access to enough patients for clinical care, teaching and education, and research. Their responsibilities to patients include, but are not limited to, detecting and analysing adverse drug effects and reactions, therapeutics, and toxicology including reproductive toxicology, perioperative drug management, and psychopharmacology. Modern clinical pharmacologists are also trained in data analysis skills. Their approaches to analyse data can include modelling and simulation techniques (e.g. population analysis, non-linear mixed-effects modelling). Branches Clinical Pharmacology consists of multiple branches listed below: Pharmacodynamics - what drugs do to the body and how. This includes not just the cellular and molecular aspects, but also more relevant clinical measurements. For example, not just the pharmacological actions of salbutamol, a beta2-adrenergic receptor agonist, but the respiratory peak flow rate of both healthy volunteers and patients. Pharmacokinetics - what happens to the drug while in the body. This involves the body systems for handling the drug, usually divided into the following classification: Absorption - the processes by which the drug move into the bloodstream from the site of administration (e.g. the gut) Distribution - the extent to which the drug enters and leaves different tissues of the body Metabolism - the processes by which the drug is metabolized in the liver, i.e. transformed into molecules that are usually less pharmacologically active Excretion - the processes by which the drug is eliminated from the body, which mostly happens in the liver and kidneys. Rational Prescribing - using the right medication, in the right dose, using the right route and frequency of administration, and for the right duration of