In Australia, the number of patients presenting to NSW hospitals for methamphetamine-related reasons has risen from 1269 in 2009-10 to 3135 in 2013-14. The number of patients being admitted to mental health units for amphetamine abuse, dependence or psychosis has risen steadily since 2009 (by comparison, the number of patients admitted due to opioid use has remained relatively steady).

What are methamphetamines?

Methamphetamines are synthetic amines (derivatives of ammonia) that can produce several sympathomimetic effects – in particular of a hallucinogenic, stimulant and euphoric nature. It used to be commonly employed by army forces during World War II to increase alertness and energy levels. In the clinical setting, it is often used to treat attention deficit disorder with hyperactivity (ADHD).

However, recreational abuse of amphetamine-derived stimulants has become epidemic worldwide over recent years.

Methamphetamine is a potent drug used illicitly in a variety of ways. Effects of the drug can occur within seconds of injection or smoking, within five minutes of intranasal use and within 20 minutes following oral ingestion. This article will discuss the damaging effects it can have on the human body, and ways to manage patients acutely intoxicated by methamphetamine use.

Some effects on the human body

• Drug-craving and drug-seeking behaviour
• Hallucinations, including auditory and visual
• Paranoia
• Severe agitation, may become aggressive towards other patients and medical staff
• Altered mood
• Deranged responses to hunger and thirst
• Dilated pupils
• Diaphoresis
• Vomiting, constipation and abdominal distension
• Hypertension
• Tachycardia
• Hyperthermia
• Vasospasm


Assessment (some important aspects)

• History – route of drug administration, amount recently ingested, frequency of use (attempt to differentiate between binges, short-term use and chronic abuse).

• General inspection – methamphetamine users are often disheveled, malnourished and agitated. Skin excoriations and track marks may be seen and suggest prolonged and IV methamphetamine use.

• A full physical examination covering every system in the body – including cardiovascular, respiratory, and gastrointestinal.

• Take a blood sample to check glucose level, full blood count, basic electrolytes, creatinine, lactate, liver function tests, coagulation studies, and a pregnancy test in women of childbearing age.

• Be wary of methamphetamine users who have a heart rate >120 beats/minute or a temperature >38°C – these people are at risk of seizures, metabolic acidosis, increased troponin, acute renal failure, hyperkalaemia, altered mental status requiring intubation, shock, coma and increased mortality.


Management

Patients with acute methamphetamine intoxication can become easily agitated, aggressive and violent. These patients often require sedation as they are at risk of harming themselves, fellow patients and hospital staff. Additionally, uncontrolled agitation may lead to adverse effects for the patient such as hyperthermia, rhabdomyolysis and cardiovascular collapse.

Initial basic management includes attempting to communicate with these patients in ways that are least likely to be seen as threatening or confrontational. This includes:

• Demonstrating to the patient that you are listening to them
• Avoiding too much eye contact
• Asking open-ended questions
• Maintaining an even tone of voice
• Allowing patients to have as much personal space as possible

However, often patients need sedating medication, and additionally benefit greatly if they have psychotic symptoms and can be given antipsychotic medication. Medications often used in this setting include diazepam, lorazepam, midazolam, olanzapine and haloperidol. These can be given orally or parenterally, depending on the level of agitation, and of course on whether or not the patient will willingly accept oral medication! In patients with high aggression risk, hospital security staff should be called to attend.

It should be noted that patients who use drugs intravenously are at greater risk of having blood-borne viruses such as hepatitis and HIV. It is (as with all patients) therefore wise to follow standard infection control precautions whilst examining patients and performing procedures like taking blood samples.

If signs of significant complications of methamphetamine use are present, additional treatment may be needed, for example:

• Hypertension – may require pharmacologic control.

• Hypovolaemia – may require IV fluid resuscitation.

• Hyperthermia (strongly linked with increased morbidity and mortality) – may require cooling blankets, sedation, fluid resuscitation, paralysis and endotracheal intubation (the paralysis is to minimise excess muscle activity, to better control body temperature).

• Seizures – often self-limiting. Initially can be treated with benzodiazepines, however further investigation for other causes of the seizure should be done.


During acute methamphetamine use, psychiatric symptoms such as paranoia, delusions, hallucinations, mood disturbance, anxiety and homicidal and suicidal ideation, may be present. Refer these patients for assessment by the psychiatric liaison team if these symptoms persist after they are no longer acutely intoxicated.

Some hospitals also have designated drug and alcohol nurses/teams. Patients should be referred to them prior to discharge, for advice on current management and for help in linking patients to appropriate community drug and alcohol services.


After methamphetamine use – managing acute withdrawal

Withdrawal symptoms often develop within hours to two days. Symptoms include:

• Fatigue
• Vivid dreams
• Agitation
• Dysphoria (may develop into persisting depression and suicidal thoughts)
• Anhedonia
• Insomnia
• Drug craving
• Increased appetite

Management generally involves prescription of benzodiazepines, antipsychotics, antidepressants or therapy. Admission to an acute withdrawal drug facility may be possible and beneficial. Patients should also be encouraged to follow-up with their regular family doctor/GP.


Patient disposition

Certain patients may, due to persisting significant psychiatric symptoms, require admission to a psychiatric ward for some time. For those not requiring admission, patients can be discharged from hospital and referred on to various outpatient drug and alcohol services. These range from short clinic appointments to long-term residential rehabilitation.

Sources
• http://www.uptodate.com/contents/methamphetamine-intoxication
• http://www.nurseuncut.com.au/ice-where-to-from-here/
• http://www.health.nsw.gov.au/crystallinemethamphetamine/Publications/background-paper.pdf
• http://www.health.gov.au/internet/drugstrategy/publishing.nsf/Content/9DFC79ECB850641ECA2571F40016229F/$File/emergency-book.pdf
• http://www.australianprescriber.com/magazine/34/4/115/8