Rapid Tolerance Development, also known as tachyphylaxis, occurs when the body and brain become physiologically resistant to the effects of drugs. Rapid Tolerance Development tends to occur relatively quickly, within short periods of repeated drug use. When Rapid Tolerance Development occurs, even an increase in drug dosage will not generally achieve desired effects. There are many reasons why rapid tolerance develops, including drug of choice, personal chemistry or prior dependencies.
Basic Reasons for Rapid Tolerance Development
While some drugs take chronic use to begin to build tolerance in a user, others trigger a rapid decline in response over a short timespan. With repeated doses, the chemical messengers in the brain—known as neurotransmitters creating sedative, stimulant or hallucinogenic effects no longer begin to become depleted. After several doses, the neurotransmitter no longer has a reserve to release when the drug is ingested, and the user no longer feels a “high.” Many users will then begin to increase intake in an attempt to achieve the prior effects, or combine drug use, leading to life-threatening conditions or even fatal overdose.
Reasons for Rapid Tolerance Development in Addictive Drugs
Amphetamine dependent individuals tend to experience Rapid Tolerance Development. Amphetamines such as ephedrine, methamphetamine, or Adderall deplete the neurotransmitter noradrenaline in the brain, affecting the nerve terminals. As repeated doses are ingested, noradrenaline is triggered for release with lower reserves, leading to diminished stimulant effects.
Opioids are another source of Rapid Tolerance Development, depending on frequency of use and intensity of dosage. As users begin to take drugs such as Vicodin or morphine, opioid receptors become affected, developing rapid tolerance and creating a need for higher dosages to achieve painkilling or sedative effects.
Psychedelic drugs can also create Rapid Tolerance Development in dependent individuals. When users of hallucinogens such as LSD and psilocybin (found in “magic mushrooms,” peyote, and mescaline) take repeated doses, tolerance sets in extremely rapidly. This is one of the reasons that even die-hard hallucinogen fans can’t generally “trip” two days in the row by using the same dose—they simply will not feel the desired effects.