This article is about the pharmacological term. For the energy conservation term, see Rebound effect (conservation).
The rebound effect, or rebound phenomenon, is the emergence or re-emergence of symptoms 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.
The rebound effect, or pharmaceutical rebound phenomenon, is the emergence or re-emergence of symptoms 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.[citation needed]
Rebound insomnia is insomnia that occurs following discontinuation of sedative substances taken to relieve primary insomnia. Regular use of these substances can cause a person to become dependent 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. Occasionally, this insomnia may be worse than the insomnia the drug was intended to treat.[1] Common medicines known to cause this problem are eszopiclone, zolpidem, and anxiolytics such as benzodiazepines 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.[2]
Daytime rebound effects of anxiety, metallic taste, perceptual disturbances which are typical benzodiazepine withdrawal symptoms can occur the next day after a short-acting benzodiazepine 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.[3][4][5]Quazepam, 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 will cause next-day rebound withdrawal effects or not.[6] Daytime rebound effects are not necessarily mild but can sometimes produce quite marked psychiatric and psychological disturbances.[7]
Another example of pharmaceutical rebound is a rebound headache from painkillers when the dose is lowered, the medication wears off, or the drug is abruptly discontinued.[17]
In 2022, reports of viral RNA and symptom rebound in people with COVID-19 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.[18]
Abrupt withdrawal of highly potent corticosteroids, such as clobetasol for psoriasis 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.[citation needed]
^Lee A, Lader M (January 1988). "Tolerance and rebound during and after short-term administration of quazepam, triazolam and placebo to healthy human volunteers". Int Clin Psychopharmacol. 3 (1): 31–47. doi:10.1097/00004850-198801000-00002. PMID2895786.
^Garland EJ (1998). "Pharmacotherapy of adolescent attention deficit hyperactivity disorder: challenges, choices and caveats". J. Psychopharmacol. (Oxford). 12 (4): 385–95. doi:10.1177/026988119801200410. PMID10065914. S2CID38304694.
^Rosenfeld AA (February 1979). "Depression and psychotic regression following prolonged methylphenidate use and withdrawal: case report". Am J Psychiatry. 136 (2): 226–8. doi:10.1176/ajp.136.2.226. PMID760559.
^Fernandez, Hubert H.; Martha E. Trieschmann; Michael S. Okun (3 Aug 2004). "Rebound psychosis: Effect of discontinuation of antipsychotics in Parkinson's disease". Movement Disorders. 20 (1): 104–105. doi:10.1002/mds.20260. PMID15390047. S2CID11574536.