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What is methamphetamine?
Methamphetamine is a powerful, highly addictive stimulant that affects the central nervous system. Crystal methamphetamine is a form of the drug that looks like glass fragments or shiny, bluish-white rocks. It is chemically similar to amphetamine, a drug used to treat attention-deficit hyperactivity disorder (ADHD) and narcolepsy, a sleep disorder.
Properties and Characteristics of Methamphetamine
| Drug class | Stimulant drugs |
| Brand Names | Desoxyn |
| Synonyms | d-deoxyephedrine, d-desoxyephedrine, d-N-methylamphetamine, d-phenylisopropylmethylamine, Dextromethamphetamine, Métamfétamine
Metamfetamine, Metamfetaminum, Metanfetamina, Methamphetamine, Methamphetaminum |
| Molecular Formula | C10H15N |
| Molecular Weight | 149.23 g/mol |
| IUPAC Name | (2S)-N-methyl-1-phenylpropan-2-amine |
| Structural formula of main components |  |
| Pure active ingredient | Methamphetamine |
| Appearance | White crystalline powder |
| Melting point | 170-2 °C |
| Solubility | Soluble in in water, 0.5 g/mL |
| Excretion | Excretion occurs primarily in the urine |
| Storage | Recommended storage temperature -20 °C |
| Available Forms | Tablet |
| Prescription | Doctor prescription is required |
Uses
This medication is used to treat attention deficit hyperactivity disorder – ADHD. It works by changing the amounts of certain natural substances in the brain. Methamphetamine belongs to a class of drugs known as stimulants. It can help increase your ability to pay attention, stay focused on an activity, and control behavior problems. It may also help you to organize your tasks and improve listening skills.This medication should not be used to treat tiredness or to hold off sleep in people who do not have a sleep disorder.
Side effects
People use methamphetamine because they enjoy the effects. However, it can have some dangerous side effects.
These include:
- Addiction
- Anxiety
- Changes in brain structure and function
- Confusion
- Sleep disorders
- Deficits in thinking and motor skills
- Mood disturbances
- Extreme weight loss
- Memory loss
- Aggressive or violent behavior
- Severe dental problems
- Skin sores from intense itching
- Rapid or irregular heart rate
- Increased blood pressure
The following symptoms of methamphetamine psychosis are also possible as long-term side effects:
- Paranoia
- Visual and auditory hallucinations
- Delusions (insects crawling on the skin)
- Repetitive behaviors
Paranoia can result in thoughts of suicide.
Psychotic symptoms can last for months or years after discontinuing methamphetamine use. And they can spontaneously reoccur.
Methamphetamine misuse can cause significant brain changes. Various studies have demonstrated alterations in the brain’s dopamine system activity associated with reduced motor speed and impaired verbal learning.
Additional research has revealed structural and functional changes in the parts of the brain that control emotions and memory.
Mechanism of action
Methamphetamine enters the brain and triggers a cascading release of norepinephrine, dopamine and serotonin. To a lesser extent methamphetamine acts as a dopaminergic and adrenergic reuptake inhibitor and in high concentrations as a monamine oxidase inhibitor (MAOI). The mechanism of action involved in producing the beneficial behavioral changes seen in hyperkinetic children receiving methamphetamine is unknown.
Interactions
Methamphetamine is metabolized by the liver enzyme CYP2D6, so CYP2D6 inhibitors will prolong the elimination half-life of methamphetamine. Methamphetamine also interacts with monoamine oxidase inhibitors (MAOIs), since both MAOIs and methamphetamine increase plasma catecholamines; therefore, concurrent use of both is dangerous. Methamphetamine may decrease the effects of sedatives and depressants and increase the effects of antidepressants and other stimulants as well. Methamphetamine may counteract the effects of antihypertensives and antipsychotics owing to its effects on the cardiovascular system and cognition respectively. The pH of gastrointestinal content and urine affects the absorption and excretion of methamphetamine. Specifically, acidic substances will reduce the absorption of methamphetamine and increase urinary excretion, while alkaline substances do the opposite. Owing to the effect pH has on absorption, proton pump inhibitors, which reduce gastric acid, are known to interact with methamphetamine.
Dosing information
Usual Adult Dose for Obesity:
5 mg orally 30 minutes before each meal
Duration of Therapy: Should not exceed a few weeks
Use: Short-term adjunct in a weight reduction regimen based on caloric restriction; for patients in whom obesity is refractory to alternative therapy (e.g., repeated diets, group programs, other drugs).
Usual Pediatric Dose for Attention Deficit Disorder:
Age 6 Years and Older:
-Initial dose: 5 mg orally once or twice a day
-Maintenance dose: Daily dosage may be raised in increments of 5 mg at weekly intervals until an optimum clinical response is achieved; the usual effective dose is 20 to 25 mg per day.
Comments:
-The total daily dose may be given in 2 divided doses.
-Where possible, drug administration should be interrupted occasionally to determine if there is a recurrence of behavioral symptoms sufficient to require continued therapy.
Use: As part of a total treatment program for Attention Deficit Hyperactivity Disorder (ADHD), a behavioral syndrome characterized by moderate to severe distractibility, short attention span, hyperactivity, emotional lability, and impulsivity.
Usual Pediatric Dose for Obesity:
Age 12 Years and Older:
5 mg orally 30 minutes before each meal
Duration of Therapy: Should not exceed a few weeks
Use: Short-term adjunct in a weight reduction regimen based on caloric restriction; for patients in whom obesity is refractory to alternative therapy (e.g., repeated diets, group programs, other drugs).
Signs of an overdose
Methamphetamine overdose is a toxic, potentially life-threatening reaction to the drug. Your risk of overdose increases if you take a large dose of meth or mix methamphetamine with other drugs.
Signs of meth overdose include:
- Increased agitation or paranoia
- Difficulty breathing
- High fever
- Severe stomach or chest pain
- Heart attack
- Cardiac arrest, or a stopped heartbeat
- Kidney damage
- Stroke
- Seizure
- Coma
If you or someone you know has any signs of an overdose, call for emergency help right away.
Prompt treatment could save their life, and it may also help reduce your risk of long-term or permanent damage.
Warnings for Methamphetamine
You should not use methamphetamine if you have glaucoma, overactive thyroid, severe agitation, moderate to severe high blood pressure, heart disease or coronary artery disease, or a history of drug abuse.
Methamphetamine may be habit-forming, and this medicine is a drug of abuse. Tell your doctor if you have had problems with drug or alcohol abuse.
Stimulants have caused stroke, heart attack, and sudden death in people with high blood pressure, heart disease, or a heart defect.
Do not use methamphetamine if you have used an MAO inhibitor in the past 14 days, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
Methamphetamine may cause new or worsening psychosis (unusual thoughts or behavior), especially if you have a history of depression, mental illness, or bipolar disorder.
You may have blood circulation problems that can cause numbness, pain, or discoloration in your fingers or toes.
Call your doctor right away if you have: signs of heart problems – chest pain, feeling light-headed or short of breath; signs of psychosis – paranoia, aggression, new behavior problems, seeing or hearing things that are not real; signs of circulation problems – unexplained wounds on your fingers or toes.
Before taking this medicine
You should not use methamphetamine if you are allergic to any stimulant medicine, or if you have:
- Moderate to severe high blood pressure;
- Heart disease or coronary artery disease (hardened arteries);
- Overactive thyroid;
- Glaucoma;
- Severe anxiety, tension, or agitation (stimulant medicine can make these symptoms worse); or
- A history of drug or alcohol addiction.
Do not use methamphetamine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.
Some medicines can interact with methamphetamine and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you also take opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson’s disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Ask your doctor before making any changes in how or when you take your medications.
