Cross-tolerance
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Cross-tolerance refers to a pharmacological phenomenon, in which a patient being treated with a drug exhibits a physiological resistance to that medication as a result of tolerance to a pharmacologically similar drug. In other words, there is a decrease in response to one drug due to exposure to another drug. It is observed in treatment with antivirals, antibiotics, analgesics and many other medications.
Cross-tolerance is particularly frequent amongst users of illicit drugs. For example, users with a high tolerance to the stimulant amphetamine may also exhibit a high tolerance to the structurally similar methamphetamine or other amphetamine-like stimulants. The phenomenon is also observed in cigarette smokers, in whom there is a demonstrably lessened sensitivity to the effects of caffeine. Cross-tolerance is also frequent in response to use of hallucinogens e.g; LSD. General tolerance to the effects of tryptamines such as psilocybin, may be dramatic in response to repeated use, and this often translates into a tolerance to effects of other drugs such as Mescaline or DMT. This is also true of benzodiazepines such as Xanax and Klonopin, even opiates as well.
