Crystal methamphetamine drug abuse

Synonyms: street names include 'meth', 'crystal meth', 'ice', 'glass', 'Tina', 'Christine', 'crank', 'tik', 'yaba' and 'crazy medicine'

See also the articles on Drug Misuse and Dependence and Dual Diagnosis (Drug Abuse with Other Psychiatric Conditions).

What is methamphetamine?

Methamphetamine (METH) is an amphetamine-type stimulant. Within the central nervous system (CNS), it blocks presynaptic catecholamine reuptake, causing hyperstimulation at the post-synapse.

Methamphetamine is available in various forms including liquid, powder, and as a crystalline substance, which can be smoked. When injected intravenously as well as when smoked, high levels of the drug are rapidly achieved in the circulation. The main effects are neurocognitive, with both a euphoric and energised state as well as psychosis, depression, and other neuropsychiatric and cognitive sequelae. Methamphetamine abusers typically go on “meth binges” lasting hours to days.¹

It is most commonly smoked in its crystal form ('ice') in a pipe or in aluminium foil, heated by a flame below; however, it can also be snorted, injected, swallowed in pill form ('yaba') or inserted rectally. Smoking the drug increases its bioavailability compared with an oral formulation and decreases plasma half-life. Mean plasma half-life after smoking is about 11 hours. Smoking approaches the bioavailability of injecting.² Its effects are compared to those of crack cocaine (euphoria, heightened arousal and increased energy) but longer-lasting due to the longer half-life. It is also highly addictive.

It can be made easily in clandestine home laboratories and is often adulterated with the chemicals used in its synthesis.

Over the 1990s, there was an epidemic of METH use in some parts of America. Amphetamine and ecstasy have also been widely used across the UK and Europe, and crystal METH has been reclassified as a Class A drug so as better to control emergent problems associated with its use.

Crystal methamphetamine drug abuse epidemiology

MA is the most frequently abused amphetamine‐type stimulant in the world. Its expanding market is shown by the increasing need for patient treatment as well as growing numbers of drug seizures worldwide. MA seizures have increased in Europe since 2002 with an all‐time high in 2015, especially in Germany, Norway, Turkey, and the Czech Republic.

Worldwide, more than 33 million people are methamphetamine abusers according to the United Nations Office on Drugs and Crime. Certain groups, such as gay men, as well as certain geographies such as the Western and Midwest United States, Australia, New Zealand, Southeast and East Asia, as well as the Czech and Slovak Republics, are disproportionately affected.¹

In the UK (2019):³

• The proportion of people who said that they had used amphetamine in the last year in England and Wales has decreased significantly, from 1.2% in 2008 to 2009, to 0.6% in 2018 to 2019. Use in the last year among adults has also fallen in Scotland, from 1.4% in 2008 to 2009, to 0.7% in 2017 to 2018.

• Prevalence of methamphetamine use is low in the UK compared to the most common stimulants (0.03% in the most recent survey in England and Wales). Its use is mostly associated with men who have sex with men in ‘chemsex’, where people have sex under the influence of drugs. In this scenario, methamphetamine is typically used alongside GHB/GBL and mephedrone.

Crystal methamphetamine is sometimes used with opioids. A study in Australia found the main motivations for co-use reported by participants were as follows:⁴

• Heroin could be used to reduce the negative side effects of heavy crystal methamphetamine use, particularly during the 'comedown' phase.

• Small quantities of crystal methamphetamine used with heroin could prolong the intoxication effect of heroin, and hence the time before opioid withdrawal.

• Co-injection of crystal methamphetamine and heroin produced a more desirable intoxication effect than using either substance on its own.

• Crystal methamphetamine provided a substitute 'high' for heroin after commencing opioid substitution therapy.

Crystal methamphetamine drug abuse symptoms (presentation)^{2 5}

Abusers typically self-administer the drug in 'runs' of several days, with intervening periods of abstinence.⁶ Whilst on a 'run', an individual may stay awake continuously for up to 10 days with little food or drink. Prolonged sleep and mild dysphoria occur as the drug wears off. Immediate subjective effects include:

• Euphoria.

• Increased alertness.

• Increased energy.

• Increased libido and enhanced sexual pleasure.

• Decreased inhibition.

• Decreased appetite.

• Decreased need for sleep.

Peripheral actions arise due to the indirect sympathomimetic effects of the drug:

• Tachycardia.

• Hypertension.

• Palpitations.

• Tachypnoea.

• Sweating and hyperthermia.

• Dry mouth.

• Decreased gastrointestinal (GI) motility.

• Dilated pupils.

• Tremor.

Central actions may account for some of the other typical behaviours and movement disorders seen such as:

• Jaw clenching.

• Repetitive jerking and choreoathetoid movements.

• Compulsion with repetitive tasks ('punding').

• Formication (sensation of flesh crawling with bugs with associated compulsive picking and infected sores).⁷

Repetitive movements, hyperactivity and difficulty focusing thought are sometimes referred to as 'tweaking'.

METH use is associated with high-risk behaviours and serious injury. In one Californian trauma series, METH overtook cannabis as the most common drug used by the trauma population between 2003-2005.⁹ Use of METH increased the risk of:

• A violent mechanism of injury.

• Gun and stab wounds.

• Attempted suicide.

• Domestic violence.

• Death from injuries.

Aside from the risks associated with the use of METH, there are hazards associated with the production of METH and toxic waste exposure. Those indirectly involved (neighbours, family members, children and emergency personnel) as well as users and producers may present with:

• Serious burns due to explosions (METH laboratories explode due to volatile substances used in production).¹⁰

• Symptoms of environmental exposure (eg, headache, nausea, dizziness, dyspnoea and eye irritation).

• Heavy metal poisoning.

Differential diagnosis

The differential is wide and includes:

• Hypertensive crisis.

• Hyperthyroidism.

• Toxicity from another stimulant/sympathomimetic/hallucinogen.

• Schizophrenia.

Be aware that many patients will not only have used METH - polydrug use (including alcohol) is the norm, so consider whether there is a mixed picture.

Investigations

• Diagnostic testing:
  

  • Urine - METH is detectable for 48 hours after use.

  • Hair analysis.

  • Meconium testing - the most accurate method in neonates.

• Other laboratory tests should be directed towards symptoms:
  

  • Blood tests - FBC, U&Es, creatine kinase (CK), cardiac enzymes.

  • ECG.

  • CXR - where there are pulmonary symptoms.

  • CT scan - where there is altered mental status.

• Sexual health promotion - offer sexually transmitted infection (STI) and pregnancy testing.

Crystal methamphetamine drug abuse treatment and management⁵

Acute intoxication

• Consider staff safety - patients may be highly agitated and unpredictable. Call for security/police back-up where necessary. Sedation with neuroleptics (eg, haloperidol) may be required.

• Management is largely supportive.

• Activated charcoal is only helpful where there has been oral ingestion.

• Benzodiazepines are indicated for seizures.

• Cooling measures may be necessary where there is hyperthermia.

• Treatment of hypertension may require intravenous beta-blockers.

• The use of olanzapine and risperidone to treat amphetamine-related psychosis is also under investigation.

• Before discharge, consider additional needs and referrals. For example, drug and alcohol team, psychiatry, social services (consider child protection issues) and genitourinary medicine (GUM) clinic.

Withdrawal⁵

• Symptoms include:
  

  • Depression.

  • Anxiety.

  • Irritability.

  • Problems with concentrating.

  • Psychomotor slowing.

  • Increased appetite.

  • Paranoia.

• Withdrawal from stimulants is considered less dangerous than from alcohol, opioids or sedatives; however, seizures are possible.

• Compared with cocaine withdrawal, METH withdrawal is considered to produce more severe and prolonged depression so careful monitoring for suicidal ideation is important.

Treatment of abuse and dependence

• There is no effective treatment currently. Research into pharmacological treatment for METH dependence is ongoing - candidate drugs have included bupropion, mirtazapine, baclofen and topiramate.¹¹ However, medication is considered primarily an adjunct to the use of psychosocial interventions.

• Outpatient behavioural therapies are the standard treatment currently in the USA. The use of cognitive behavioural therapy and contingency management have been borrowed from the treatment of cocaine addiction and applied to METH and have been shown to be effective in reducing use in the short-term, although longevity has yet to be proven.¹² Contingency management gives rewards to patients who provide drug-free urine specimens although recent research suggests this effect may last as little as 6 months.¹³¹⁴

• Support groups and 12-step treatment programmes may also offer benefit.¹⁵

Complications

For METH users

The morbidity associated with METH use is considerable:

• Myocardial infarction, dissecting aortic aneurysm, cardiomyopathy.¹⁶

• Hypertensive crises and stroke.

• Rhabdomyolysis and kidney failure.

• 'Crystal cock' (erectile dysfunction).

• GI ulcers and ischaemic colitis.

• Pulmonary hypertension.¹⁷

• Skin abscesses and lesions.

• Premature ageing.

• Cognitive impairment - confusion, memory loss, motor slowing and learning impairment.¹⁸

• 'Meth mouth' (dental decay).^{19 20}

• Psychiatric disorders:
  

  • Anxiety.

  • Depression.

  • Psychosis.

  • Suicidal ideation and behaviour.

• Malnutrition and weight loss.

• Dependence and withdrawal-related symptoms.

• Trauma-related injuries.

In pregnancy

• Placental insufficiency and abruption.

• Intrauterine growth restriction.²¹

• Prematurity.

• Cleft palate defects.

• Cardiac anomalies.

• Miscarriage and stillbirth.

For children of METH users

• Neonatal withdrawal (usually milder than with opiate withdrawal) - abnormal sleep, poor feeding, decreased movement and arousal, increased stress response.²²

• Long-term effects of intrauterine exposure are unclear - possible developmental delay.

• Neglect and abuse.

• Inadvertent poisoning and trauma.

Public health issues

• Environmental health risk from illicit laboratories and illegal toxic waste.

• Increased rate of STI transmission - in particular, HIV.²³

• Increased levels of crime and violence.

Prognosis

METH use is associated with rapid dependence and sharp physical decline, often accompanied by criminality. Cases of acute uncomplicated toxicity treated rapidly and appropriately have a good prognosis but outcome associated with chronic use is much less positive. Relapse rates following treatment for dependence are high (one study suggesting 36% under 6 months and a further 15% between 7-19 months).²⁴ Anecdotal evidence in areas with high METH use suggests significant drug-related death rates, either direct (related to toxicity) or more often indirect (eg, road traffic accidents, homicide, suicide).

Prevention

Efforts in North America have centred around education (including high-profile, 'shock' advertisements), targeted interventions to those considered high-risk (eg, pregnant women users) and law enforcement strategies such as limiting the availability of precursor substances - for example, pseudoephedrine (found in cold remedies and decongestants). This has limited success at the expense of limiting access to the public to effective medicines.²⁵