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11. Glossary


A chemical substance that binds to a receptor and mimics the effect of the physiological (endogenous) substance binding to the receptor


Marked deficiency of a type of white blood cells (granulocytes) essential for immune functioning


Sensation of restlessness and a compulsion to move constantly


A substance that binds to a receptor but produces no effect and inhibits an agonist from binding to the receptor.

Anticholinergic effects

See Antimuscarinic effects—most anticholinergic effects involve the muscarinic receptor for acetylcholine


A substance that blocks the effects of histamine. Histamine is released when the body mounts an immune response; also, histamine is a neurotransmitter and it regulates the functioning of the gastrointestinal system. Of the histamine receptors; histamine H1 receptor is involved in immune reactions, motion sickness and sleep regulation, while histamine H3 receptor is activated by histamine acting as a neurotransmitter

Antimuscarinic effects

Reduction or blocking of the effects of parasympathetic nerves; antimuscarinic effects include dry mouth, difficulty swallowing, blurred vision, confusion, palpitations, constipation, and urine retention

Apgar score

The result of Apgar test on a newborn 1 minute after birth and again 5 minutes after birth. The test evaluates skin coloration (appearance), heart rate (pulse), reflex irritability (grimace response),activity and muscle tone, and breathing rate and effort (respiration). Each of the five observations is scored on a scale of 0 to 2, with 2 being the best score.

Bipolar disorder

A psychiatric disorder involving periods lasting several weeks or months of depressive phases (intense depression and despair), manic phases (extreme elation or irritability) and/or mixed mood (eg depression accompanied by overactivity)


The patient and the health professional agreeing on the health outcomes that the patient desires and on the strategy for achieving them


Substances that mimic effects of hormones produced by the adrenal cortex. The term corticosteroids covers glucocorticoids (steroids which reduce inflammation) and mineralocorticoids (steroids which act on the kidneys to retain sodium and water and promote excretion of potassium)

Creatine kinase

An enzyme found in many body tissues. Raised concentration is a marker for muscle damage and disorders such as myocardial infarction, muscular dystrophy and renal failure. Creatine kinase (CK) is also referred to as creatine phosphokinase (CPK)


A neurologically based movement disorder involving involuntary movement such as tremors and writhing and diminished ability to initiate voluntary movement.


Difficulty or pain on swallowing


Feeling uneasy, anxious or dissatisfied


A neurologically based movement disorder involving sustained contraction of the affected muscles, leading to abnormal posturing or repetitive movements or both


Blockage in an artery which obstructs blood flow, usually derived from a blockage elsewhere in the circulation. A common source of pulmonary (lung) embolus is a blood clot (thrombus) in the veins which breaks off and becomes lodged in the pulmonary artery.

Extrapyramidal effects

Extrapyramidal symptoms or side effects describe movement disorders such as acute dystonia, parkinsonian effects, akathisia and tardive dyskinesia; these effects result from disturbance—by dopamine antagonists—of the extrapyramidal system, which is responsible for involuntary reflexes and coordination of movement. (The voluntary movement system runs through the ‘pyramidal pathways’ of the medulla of the brain).


Raised emotional and physiological tension characterised by features such as anxiety, insomnia, fatigue, accentuated personality traits, and exaggerated startle response and pain perception.


Abnormally increased time spent sleeping


Of unknown cause or arising spontaneously; for example, idiopathic Parkinson’s disease.


Subjective understanding or awareness of the presence and extent of psychiatric illness or behavioural disorder


Presence in the blood of ketones, which are toxic byproducts of fat metabolism; fat is metabolised instead of glucose in patients with insulin deficit (diabetes).


An increase in the number of white cells in the blood, usually in response to inflammation. Leucocytosis can also be abnormally triggered by drugs.

Metabolic syndrome

Features of the metabolic syndrome include central obesity, together with two of: raised triglycerides, reduced HDL-cholesterol, raised blood pressure and raised fasting plasma glucose (or previously diagnosed type 2 diabetes)


Medicines and Healthcare products Regulatory Agency, the government body which regulates many aspects of the testing, manufacture, supply, and use of medicines and medical devices


Muscle pain


Prolonged, abnormal increase in the size of the pupil of the eye


Brief, involuntary twitching of the muscles which may produce a spasmodic or jerking movement.


A chemical substance released by a nerve cell at the junction between two nerve cells (synapse), which can stimulate or inhibit the other nerve cell. Examples of neurotransmitters include acetylcholine, dopamine, noradrenaline and serotonin.


Marked deficiency of a type of white blood cell (neutrophil) responsible for ingesting bacteria

Oculogyric crisis

A paroxysm in which the eyeballs are held in a fixed position, usually with the eyes upwards, for several minutes or hours


A spasm with the head, neck and spine arched backwards to a ‘bridging’ position’


Sensation of numbness or tingling in the skin, popularly known as ‘pins and needles’.

Parkinsonian symptoms

A clinical triad involving tremor, muscle rigidity and bradykinesia (slow movements) The symptoms often characterise Parkinson’s disease, but can also be caused by drugs, particularly antagonists of dopamingeric transmission in the nigrostriatal region of the brain.


State of having body temperature that varies with that of the environment


The occurrence of two or more different forms of genetically determined entities (eg enzymes and receptors), due to variation in the genetic material between individuals


Symptoms involving loss of contact with reality, including hallucinations (affecting hearing, smell, feel or sight), delusions, paranoia, and thought disorders; the individual may appear unusually withdrawn or excited. The components of psychosis are often described as ‘positive’ symptoms (such as hallucinations and delusions), ‘negative’ symptoms (such as apathy and withdrawal) and ‘cognitive symptoms’ (such as difficulties performing complex tasks). Psychoses can result from brain injury (eg through trauma, stroke, tumours, and infection), or the use of (usually illicit) drugs, or as a result of psychiatric disorders such as schizophrenia and severe mood disorders.

Psychotropic action

The ability of a chemical substance to affect brain function, in particular those brain systems which subserve mental activity. The psychotropic action of a drug is usually (but not always) related to an ability to interact with neurotransmitter receptors in the brain.

Pulmonary embolism

Blood clot in the lung

QT interval

The period between the start of the QRS complex (on an electrocardiogram [ECG]) to the end of the T wave. Prolongation of the QT interval is associated with potentially very serious rhythm disorders such as torsades de pointes


A mental disorder which affects how the individual feels, behaves and thinks—see psychosis


A chemical agent (or synapse) that produces its effects via the serotonin transmitter system.


Serotonin (also called 5-hydroxytryptamine) is a neurotransmitter in the brain. Also, it is involved in platelet function and affects the gastrointestinal system and blood vessels

Summary of product characteristics (SmPC)

Summary of product characteristics, a document that forms the basis of information for European Union health professionals on how to use a medicinal product safely and effectively; it reflects the data assessed for granting marketing authorisation


Temporary partial or complete loss of consciousness; a faint

Tardive dyskinesia

Involuntary, repetitive, purposeless movements, involving the face, jaw, neck, trunk and other parts, which can follow long-term use of an antipsychotic


Tolerance follows repetitive exposure to a drug, leading to a reduction of the pharmacological effect of that drug


A movement disorder in which the neck muscles persistently turn the head to one side or cause jerking; also termed ‘wry neck’