Paradoxical reaction
Encyclopedia
A paradoxical reaction or paradoxical effect is when medical treatment, usually a drug, has the opposite effect to that which would normally be expected.
An example of a paradoxical reaction is when a pain
relief medication causes an increase in pain. Some sedative
s prescribed for adults actually cause hyperactivity in children.
, with or without suicidal tendencies, phobias, aggressiveness, violent behavior
and symptoms sometimes misdiagnosed as psychosis
. Benzodiazepine
s, a class of psychoactive drugs called the "minor" tranquilizer
s, have varying hypnotic
, sedative
, anxiolytic
, anticonvulsant
, and muscle relaxing
properties, but they may create the exact opposite effects. Susceptible individuals may respond to benzodiazepine treatment with an increase in anxiety
, aggressiveness, agitation
, confusion
, disinhibition
, loss of impulse control, talkativeness, violent behavior, and even convulsions. Paradoxical adverse effects may even lead to criminal behaviour. Severe behavioral changes resulting from benzodiazepines have been reported including mania
, schizophrenia
, anger, impulsivity, and hypomania
. Self aggression has been reported and also demonstrated in laboratory conditions in a clinical study. Diazepam was found to increase people's willingness to harm themselves. Paradoxical effects of benzodiazepines appear to be dose related, that is, likelier to occur with higher doses. In a letter to the British Medical Journal
, it was reported that a high proportion of parents referred for actual or threatened child abuse
were taking drugs at the time, often a combination of benzodiazepines and tricyclic antidepressants. Many mothers described that instead of feeling less anxious or depressed, they became more hostile and openly aggressive towards the child as well as to other family members while consuming tranquilizers. The author warned that environmental or social stresses such as difficulty coping with a crying baby combined with the effects of tranquilizers may precipitate a child abuse event. Benzodiazepines can sometimes cause a paradoxical worsening of EEG
readings in patients with seizure disorders.
Paradoxical rage reactions due to benzodiazepines occur as a result of an altered level of consciousness, which generates automatic behaviors, anterograde amnesia
and uninhibited aggression. These aggressive reactions may be caused by a disinhibiting serotonergic
mechanism.
can cause hyperactivity in children. This may follow after a small dose of 20 mg, on condition of no phenobarbital administered in previous days. Prerequisity for this reaction is a continued sense of tension. The mechanism of action is not known, but it may be started by the anxiolytic action of the phenobarbital.
, an antipsychotic
and antiemetic
drug, which is classed as a "major" tranquilizer
may cause paradoxical effects such as agitation, excitement, insomnia, bizarre dreams, aggravation of psychotic symptoms and toxic confusional states.
ren and adolescents
are particularly sensitive to paradoxical reactions of self harm and suicidal ideation
while taking antidepressants.
agent. Initially when an antibiotic
agent is added to a culture media, the number of bacteria
that survive drops, as one would expect. But after increasing the concentration beyond a certain point, the number of bacteria that survive, paradoxically, increases.
One of the explanations could be that as the concentration is too high, the agent might be self-antagonising
the receptor with which it binds (penicillin
binding proteins, for example, in the case of a penicillin). Another explanation could be that the antimicrobial agent precipitates out of solution, so activity is either not seen, or that the colorimeter is detecting crystals of an antimicrobial
.
An example of a paradoxical reaction is when a pain
Pain
Pain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
relief medication causes an increase in pain. Some sedative
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....
s prescribed for adults actually cause hyperactivity in children.
Benzodiazepines
For example, there are serious complications occurring in conjunction with the use of sedatives creating a series of effects in some people, that are the total opposite of those expected. Malcolm Lader at the Institute of Psychiatry in London estimates the incidence of these adverse reactions at about 5%, even in short-term use of the drugs. The paradoxical reactions may consist of depressionDepression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
, with or without suicidal tendencies, phobias, aggressiveness, violent behavior
Violence
Violence is the use of physical force to apply a state to others contrary to their wishes. violence, while often a stand-alone issue, is often the culmination of other kinds of conflict, e.g...
and symptoms sometimes misdiagnosed as psychosis
Psychosis
Psychosis means abnormal condition of the mind, and is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality"...
. Benzodiazepine
Benzodiazepine
A benzodiazepine is a psychoactive drug whose core chemical structure is the fusion of a benzene ring and a diazepine ring...
s, a class of psychoactive drugs called the "minor" tranquilizer
Tranquilizer
A tranquilizer, or tranquilliser , is a drug that induces tranquility in an individual.The term "tranquilizer" is imprecise, and is usually qualified, or replaced with more precise terms:...
s, have varying hypnotic
Hypnotic
Hypnotic drugs are a class of psychoactives whose primary function is to induce sleep and to be used in the treatment of insomnia and in surgical anesthesia...
, sedative
Sedative
A sedative or tranquilizer is a substance that induces sedation by reducing irritability or excitement....
, anxiolytic
Anxiolytic
An anxiolytic is a drug used for the treatment of anxiety, and its related psychological and physical symptoms...
, anticonvulsant
Anticonvulsant
The anticonvulsants are a diverse group of pharmaceuticals used in the treatment of epileptic seizures. Anticonvulsants are also increasingly being used in the treatment of bipolar disorder, since many seem to act as mood stabilizers, and in the treatment of neuropathic pain. The goal of an...
, and muscle relaxing
Muscle relaxant
A muscle relaxant is a drug which affects skeletal muscle function and decreases the muscle tone. It may be used to alleviate symptoms such as muscle spasms, pain, and hyperreflexia. The term "muscle relaxant" is used to refer to two major therapeutic groups: neuromuscular blockers and spasmolytics...
properties, but they may create the exact opposite effects. Susceptible individuals may respond to benzodiazepine treatment with an increase in anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, aggressiveness, agitation
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, confusion
ConFusion
ConFusion is an annual science fiction convention organized by the Stilyagi Air Corps and its parent organization, the Ann Arbor Science Fiction Association. Commonly, it is held the third weekend of January. It is the oldest science fiction convention in Michigan, a regional, general SF con...
, disinhibition
Disinhibition
Disinhibition is a term in psychology used to describe a lack of restraint manifested in several ways, including disregard for social conventions, impulsivity, and poor risk assessment. Disinhibition affects motor, instinctual, emotional, cognitive and perceptual aspects with signs and symptoms...
, loss of impulse control, talkativeness, violent behavior, and even convulsions. Paradoxical adverse effects may even lead to criminal behaviour. Severe behavioral changes resulting from benzodiazepines have been reported including mania
Mania
Mania, the presence of which is a criterion for certain psychiatric diagnoses, is a state of abnormally elevated or irritable mood, arousal, and/ or energy levels. In a sense, it is the opposite of depression...
, schizophrenia
Schizophrenia
Schizophrenia is a mental disorder characterized by a disintegration of thought processes and of emotional responsiveness. It most commonly manifests itself as auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social...
, anger, impulsivity, and hypomania
Hypomania
Hypomania is a mood state characterized by persistent and pervasive elevated or irritable mood, as well as thoughts and behaviors that are consistent with such a mood state...
. Self aggression has been reported and also demonstrated in laboratory conditions in a clinical study. Diazepam was found to increase people's willingness to harm themselves. Paradoxical effects of benzodiazepines appear to be dose related, that is, likelier to occur with higher doses. In a letter to the British Medical Journal
British Medical Journal
BMJ is a partially open-access peer-reviewed medical journal. Originally called the British Medical Journal, the title was officially shortened to BMJ in 1988. The journal is published by the BMJ Group, a wholly owned subsidiary of the British Medical Association...
, it was reported that a high proportion of parents referred for actual or threatened child abuse
Child abuse
Child abuse is the physical, sexual, emotional mistreatment, or neglect of a child. In the United States, the Centers for Disease Control and Prevention and the Department of Children And Families define child maltreatment as any act or series of acts of commission or omission by a parent or...
were taking drugs at the time, often a combination of benzodiazepines and tricyclic antidepressants. Many mothers described that instead of feeling less anxious or depressed, they became more hostile and openly aggressive towards the child as well as to other family members while consuming tranquilizers. The author warned that environmental or social stresses such as difficulty coping with a crying baby combined with the effects of tranquilizers may precipitate a child abuse event. Benzodiazepines can sometimes cause a paradoxical worsening of EEG
EEG
EEG commonly refers to electroencephalography, a measurement of the electrical activity of the brain.EEG may also refer to:* Emperor Entertainment Group, a Hong Kong-based entertainment company...
readings in patients with seizure disorders.
Paradoxical rage reactions due to benzodiazepines occur as a result of an altered level of consciousness, which generates automatic behaviors, anterograde amnesia
Anterograde amnesia
Anterograde amnesia is a loss of the ability to create new memories after the event that caused the amnesia, leading to a partial or complete inability to recall the recent past, while long-term memories from before the event remain intact. This is in contrast to retrograde amnesia, where memories...
and uninhibited aggression. These aggressive reactions may be caused by a disinhibiting serotonergic
Serotonergic
Serotonergic or serotoninergic means "related to the neurotransmitter serotonin". A synapse is serotonergic if it uses serotonin as its neurotransmitter...
mechanism.
Barbiturates
PhenobarbitalPhenobarbital
Phenobarbital or phenobarbitone is a barbiturate, first marketed as Luminal by Friedr. Bayer et comp. It is the most widely used anticonvulsant worldwide, and the oldest still commonly used. It also has sedative and hypnotic properties but, as with other barbiturates, has been superseded by the...
can cause hyperactivity in children. This may follow after a small dose of 20 mg, on condition of no phenobarbital administered in previous days. Prerequisity for this reaction is a continued sense of tension. The mechanism of action is not known, but it may be started by the anxiolytic action of the phenobarbital.
Antipsychotics
ChlorpromazineChlorpromazine
Chlorpromazine is a typical antipsychotic...
, an antipsychotic
Antipsychotic
An antipsychotic is a tranquilizing psychiatric medication primarily used to manage psychosis , particularly in schizophrenia and bipolar disorder. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s...
and antiemetic
Antiemetic
An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of opioid analgesics, general anaesthetics, and chemotherapy directed against cancer....
drug, which is classed as a "major" tranquilizer
Tranquilizer
A tranquilizer, or tranquilliser , is a drug that induces tranquility in an individual.The term "tranquilizer" is imprecise, and is usually qualified, or replaced with more precise terms:...
may cause paradoxical effects such as agitation, excitement, insomnia, bizarre dreams, aggravation of psychotic symptoms and toxic confusional states.
Antidepressants
Antidepressants can sometimes make users obsessively violent or have suicidal compulsions, which is in marked contrast to their intended effect. This can be regarded as a paradoxical reaction. ChildChild
Biologically, a child is generally a human between the stages of birth and puberty. Some vernacular definitions of a child include the fetus, as being an unborn child. The legal definition of "child" generally refers to a minor, otherwise known as a person younger than the age of majority...
ren and adolescents
Adolescence
Adolescence is a transitional stage of physical and mental human development generally occurring between puberty and legal adulthood , but largely characterized as beginning and ending with the teenage stage...
are particularly sensitive to paradoxical reactions of self harm and suicidal ideation
Suicidal ideation
Suicidal ideation is a common medical term for thoughts about suicide, which may be as detailed as a formulated plan, without the suicidal act itself. Although most people who undergo suicidal ideation do not commit suicide, some go on to make suicide attempts...
while taking antidepressants.
Antibiotics
The paradoxical effect or Eagle phenomenon (named after H. Eagle who first described it) refers to an observation of an increase in survivors, seen when testing the activity of an antimicrobialAntimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
agent. Initially when an antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
agent is added to a culture media, the number of bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
that survive drops, as one would expect. But after increasing the concentration beyond a certain point, the number of bacteria that survive, paradoxically, increases.
One of the explanations could be that as the concentration is too high, the agent might be self-antagonising
Receptor antagonist
A receptor antagonist is a type of receptor ligand or drug that does not provoke a biological response itself upon binding to a receptor, but blocks or dampens agonist-mediated responses...
the receptor with which it binds (penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
binding proteins, for example, in the case of a penicillin). Another explanation could be that the antimicrobial agent precipitates out of solution, so activity is either not seen, or that the colorimeter is detecting crystals of an antimicrobial
Antimicrobial
An anti-microbial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Antimicrobial drugs either kill microbes or prevent the growth of microbes...
.