Methamphetamine: general

Methamphetamine is a lab-made central nervous system stimulant [1][2] with high addiction potential [1][2]. It's the racemic free base mixture of two mirror-image forms, levomethamphetamine and dextromethamphetamine [3][4]. Only the d-isomer, as Desoxyn, remains FDA-approved today, sold in 5 mg tablets [5][1]. Its clinical use is limited — to treatment of obesity and ADHD — due to concerns about abuse liability [5][1]. When sold as shiny bluish-white rocks or crystals, it's called crystal meth, Tina, or ice [2].

Short-term, it produces euphoria, alertness, and energy [2].

Stimulants as a class build up excess norepinephrine and dopamine in the space between nerve cells, and that excess drives the sympathetic nervous system into overdrive: heightened alertness, dilated pupils, racing heart, high blood pressure, high body temperature, and seizures [6]. Paranoia, anxiety, rapid or irregular heartbeat, stroke, and death are all documented effects [2].

Two things matter most before anything else. First, stimulant overdose doesn't look the same from one person to the next — what it looks like depends on other health conditions, the specific stimulant, how it's taken, and the dose [7]. Don't wait for a textbook picture before treating something as an emergency; no medication reverses a stimulant overdose the way naloxone reverses an opioid one, but medical treatment can manage the acute symptoms [8]. Naloxone should be used in stimulant overdoses when opioids are also involved [8].

Second, combinations raise the stakes. Sympathomimetic toxicity can result from one stimulant taken to excess or from several drugs used in combination [6], and at the extreme, overdose of sympathomimetics can produce cardiovascular collapse and multiorgan failure [6].

References

1. METHAMPHETAMINE (Trade Name: Desoxyn®; Street Names: Meth, Speed, Crystal, Glass, Ice, Crank, Yaba) — U.S. Drug Enforcement Administration (DEA) Diversion Control Division
2. Methamphetamine Research Report Overview — National Institute on Drug Abuse (NIDA)
3. Methamphetamine | Ligand page | IUPHAR/BPS Guide to PHARMACOLOGY — IUPHAR/BPS Guide to PHARMACOLOGY
4. Methamphetamine — Wikipedia
5. Methamphetamine - StatPearls — NCBI Bookshelf (StatPearls)
6. Sympathomimetic Toxicity – StatPearls — NCBI Bookshelf
7. Stimulant Guide: Overdose Prevention and Response — Centers for Disease Control and Prevention
8. SAMHSA Overdose Prevention and Response Toolkit — Substance Abuse and Mental Health Services Administration