What to Actually Remember

Every module had a User Manual section. This page is all of them in one place — the practical layer on top of the neuroscience. The framework underneath everything is still the same:

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Tolerance Dynamics

• Euphoria tolerance fades faster than respiratory depression tolerance.
• Opioid respiratory tolerance decreases during periods of abstinence.
• Resuming opioid use requires a dose reduction to 25–50% of the previous baseline.
• Stimulant and depressant doses also require reduction following any period of cessation.
• Psychedelic tolerance resets within 1–2 weeks; subsequent equivalent doses will produce stronger effects.

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Pharmacological Interactions

• Polysubstance interactions multiply shared downstream effects (e.g., respiratory depression, serotonin load).
• Depressants are present in the majority of polysubstance overdose deaths.
• Cross-tolerance occurs between depressants that share a mechanism (alcohol, benzodiazepines, barbiturates, GHB). It does not extend to opioids — they act on different receptors.
• Stimulants and depressants mutually mask physiological symptoms, increasing the likelihood of overdose via redosing.
• Combining opioids and depressants creates a high risk of severe respiratory depression.
• Combining psychedelics and lithium carries a documented risk of seizures.
• MDMA requires a 6–12 week dosing interval to allow serotonin system recovery and limit neurotoxicity risk.

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Supply and Adulteration

• US street opioids should be assumed to contain fentanyl unless tested otherwise.
• Batch purity fluctuates significantly (e.g., 0.1% to 64.9% fentanyl by weight); established tolerance does not compensate for these variations.
• Naloxone reverses opioid-mediated respiratory depression but has no mechanism of action against common adulterants like xylazine or medetomidine.
• Persistent respiratory depression after naloxone administration requires emergency medical evaluation.

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Thermoregulation and Fluid Balance

• Stimulants cause vasoconstriction, impairing hypothalamic heat regulation and increasing the risk of hyperthermia (critical at 41–42°C).
• Dose stacking multiplies cardiovascular risk; symptoms such as chest pain, severe headache, or confusion indicate a need for immediate medical assessment.
• MDMA increases core temperature and systemic water retention.
• Excessive consumption of plain water on MDMA can cause hyponatremia. Fluid intake should be limited to roughly 500 ml/hour and include electrolytes.

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Depressant Withdrawal

• Abrupt cessation of depressants (alcohol, benzodiazepines, GHB, phenibut, gabapentinoids) can result in seizures, cardiovascular instability, and hyperthermia.
• Depressant withdrawal carries acute physiological risks not typically present in opioid withdrawal.
• Sustained use of depressants or psychiatric medications necessitates a medical taper to accommodate neurological adjustments.

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Formulation Pharmacology

• The pharmacological profiles of plant-derived drugs do not directly translate to their isolated derivatives or concentrates.
• Transitioning from whole-plant products to concentrates shifts the dose-response curve.
• Synthetic cannabinoids act as full agonists, which can produce severe physiological and psychological effects distinct from partial agonists like natural cannabis.

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Dependence Statistics

• Population-level dependence rates do not dictate individual physiological or psychological risk.
• Individual dependence probability is influenced by genetics, mental health history, administration route, age of onset, and frequency of use.
• The presence of multiple risk factors increases individual dependence probability above baseline population averages.

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