The rebound effect, or rebound phenomenon, is the emergence or re-emergence of

symptom Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showin ...

s that were either absent or controlled while taking a medication, but appear when that same medication is discontinued, or reduced in dosage. In the case of re-emergence, the severity of the symptoms is often worse than pretreatment levels.

Definition

The rebound effect, or

pharmaceutical A medication (also called medicament, medicine, pharmaceutical drug, medicinal drug or simply drug) is a drug used to diagnose, cure, treat, or prevent disease. Drug therapy (pharmacotherapy) is an important part of the medical field and re ...

rebound phenomenon, is the emergence or re-emergence of

Examples

Sedative hypnotics

Rebound insomnia is

insomnia Insomnia, also known as sleeplessness, is a sleep disorder in which people have trouble sleeping. They may have difficulty falling asleep, or staying asleep as long as desired. Insomnia is typically followed by daytime sleepiness, low energy, ...

that occurs following discontinuation of

sedative A sedative or tranquilliser is a substance that induces sedation by reducing irritability or excitement. They are CNS depressants and interact with brain activity causing its deceleration. Various kinds of sedatives can be distinguished, but t ...

substances taken to relieve primary insomnia. Regular use of these substances can cause a person to become

dependent A dependant is a person who relies on another as a primary source of income. A common-law spouse who is financially supported by their partner may also be included in this definition. In some jurisdictions, supporting a dependant may enabl ...

on its effects in order to fall asleep. Therefore, when a person has stopped taking the medication and is 'rebounding' from its effects, they may experience insomnia as a symptom of

withdrawal Withdrawal means "an act of taking out" and may refer to: * Anchoresis (withdrawal from the world for religious or ethical reasons) * ''Coitus interruptus'' (the withdrawal method) * Drug withdrawal * Social withdrawal * Taking of money from a ban ...

. Occasionally, this insomnia may be worse than the insomnia the drug was intended to treat. Common medicines known to cause this problem are eszopiclone, zolpidem, and anxiolytics such as

benzodiazepines Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, i ...

and which are prescribed to people having difficulties falling or staying asleep. Rebound depression may appear to arise in patients previously free of such an illness. Daytime rebound effects of anxiety, metallic taste, perceptual disturbances which are typical

benzodiazepine withdrawal symptoms Benzodiazepine withdrawal syndrome often abbreviated to benzo withdrawal or BZD withdrawal is the cluster of signs and symptoms that may emerge when a person who has been taking benzodiazepines, either medically or recreationally develops a p ...

can occur the next day after a short-acting

benzodiazepine Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...

hypnotic wears off. Rebound phenomena do not necessarily only occur on discontinuation of a prescribed dosage. Another example is early morning rebound insomnia which may occur when a rapidly eliminated hypnotic wears off which leads to rebounding awakeness forcing the person to become wide awake before he or she has had a full night's sleep. One drug which seems to be commonly associated with these problems is triazolam, due to its high potency and ultra short half life, but these effects can occur with other short-acting

hypnotic drugs Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...

Quazepam Quazepam, sold under brand name Doral among others, is a relatively long-acting benzodiazepine derivative drug developed by the Schering Corporation in the 1970s. Quazepam is used for the treatment of insomnia including sleep induction and sleep ...

, due to its selectivity for type1 benzodiazepine receptors and long half-life, does not cause daytime anxiety rebound effects during treatment, showing that half-life is very important for determining whether a nighttime

hypnotic Hypnotic (from Greek ''Hypnos'', sleep), or soporific drugs, commonly known as sleeping pills, are a class of (and umbrella term for) psychoactive drugs whose primary function is to induce sleep (or surgical anesthesiaWhen used in anesthesia ...

will cause next-day rebound withdrawal effects or not. Daytime rebound effects are not necessarily mild but can sometimes produce quite marked psychiatric and psychological disturbances.

Stimulants

Rebound effects from

stimulants Stimulants (also often referred to as psychostimulants or colloquially as uppers) is an overarching term that covers many drugs including those that increase activity of the central nervous system and the body, drugs that are pleasurable and inv ...

such as

methylphenidate Methylphenidate, sold under the brand names Ritalin and Concerta among others, is the most widely prescribed central nervous system (CNS) stimulant medication used to treat attention deficit hyperactivity disorder (ADHD) and, to a lesser extent, ...

or dextroamphetamine include

stimulant psychosis Stimulant psychosis is a mental disorder characterized by psychotic symptoms (such as hallucinations, paranoid ideation, delusions, disorganized thinking, grossly disorganized behaviour) which involves and typically occurs following an overdose or ...

, depression and a return of ADHD symptoms but in a temporarily exaggerated form. Up to a third of ADHD children experience a rebound effect when methylphenidate is withdrawn.

Antidepressants

Many

antidepressant Antidepressants are a class of medication used to treat major depressive disorder, anxiety disorders, chronic pain conditions, and to help manage addictions. Common side-effects of antidepressants include dry mouth, weight gain, dizziness, hea ...

s, including SSRIs, can cause rebound depression, panic attacks,

anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil and includes feelings of dread over anticipated events. Anxiety is different than fear in that the former is defined as the anticipation of a future threat wh ...

, and

when discontinued.

Antipsychotics

Sudden and severe emergence or re-emergence of psychosis may appear when

antipsychotic Antipsychotics, also known as neuroleptics, are a class of Psychiatric medication, psychotropic medication primarily used to manage psychosis (including delusions, hallucinations, paranoia or disordered thought), principally in schizophrenia but ...

s are

switched Switched may refer to: * Switched (band), an American music group * ''Switched'' (novel), first book in the young adult Trylle series by Amanda Hocking * ''Switched!'' (American TV series) * ''Switched!'' (Singaporean TV series) * "Switched" (' ...

or discontinued too rapidly.

Alpha-2 adrenergic agents

Rebound hypertension, above pre-treatment level, was observed after

clonidine Clonidine, sold under the brand name Catapres among others, is an α2-adrenergic agonist medication used to treat high blood pressure, ADHD, drug withdrawal ( alcohol, opioids, or nicotine), menopausal flushing, diarrhea, spasticity, and c ...

, and guanfacine discontinuation. Continuous usage of

topical decongestant Topical decongestants are decongestants applied directly to the nasal cavity. Their effectiveness by themselves in the common cold appears to have a small benefit in adults. Topical decongestants should only be used by patients for a maximum of 5� ...

s (''

nasal spray Nasal sprays are used to deliver medications locally in the nasal cavities or systemically. They are used locally for conditions such as nasal congestion and allergic rhinitis. In some situations, the nasal delivery route is preferred for syste ...

s'') can lead to constant nasal congestion, known as

rhinitis medicamentosa Rhinitis medicamentosa (or RM) is a condition of rebound nasal congestion suspected to be brought on by extended use of topical decongestants (e.g., oxymetazoline, phenylephrine, xylometazoline, and naphazoline nasal sprays) and certain oral medic ...

Other medications

Another example of

rebound is a rebound headache from painkillers when the dose is lowered, the medication wears off, or the drug is abruptly discontinued. In 2022, reports of viral RNA and symptom rebound in people with

COVID-19 Coronavirus disease 2019 (COVID-19) is a contagious disease caused by a virus, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The first known case was COVID-19 pandemic in Hubei, identified in Wuhan, China, in December ...

treated with Paxlovid were published. In May, CDC even issued a health alert informing physicians about "Paxlovid rebounds", which received attention when US president Joe Biden experienced a rebound. The cause of the rebound is unclear however, since around a third of people with COVID-19 experience a symptom rebound regardless of treatment. Abrupt withdrawal of highly potent

corticosteroid Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...

s, such as

clobetasol Clobetasol is a synthetic glucocorticoid corticosteroid. A propionate ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), a ...

for

psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete ...

can cause a much more severe case of the psoriasis to develop. Therefore, withdrawal should be gradual, until very little actual medication is being applied.

References

{{Psychoactive substance use Clinical pharmacology Psychiatric diagnosis