What are the health concerns and treatment options for methamphetamine use?

Methamphetamine: Health Concerns and Treatment

Acute Cardiovascular Complications

Methamphetamine causes real acute coronary syndromes through coronary vasospasm, increased platelet aggregation, and can precipitate true STEMI even in patients with normal coronary arteries. 1

Cardiovascular Mechanisms and Risks

Methamphetamine produces a hyperadrenergic state by blocking neuronal reuptake of norepinephrine and dopamine, leading to: 2

• Increased heart rate and blood pressure (sometimes dramatically) 2
• Coronary vasoconstriction with elevated myocardial oxygen demand, producing myocardial ischemia and infarction even without obstructive CAD 2
• Decreased myocardial perfusion and reduced coronary sinus blood flow 2
• Up to 70% of methamphetamine users have abnormal ECGs, with tachycardia being the most common finding 2
• Additional ECG abnormalities attributed to hypertension, pulmonary artery hypertension, and cardiomyopathy 2

Acute Intoxication Management

Benzodiazepines are the cornerstone of therapy for all sympathomimetic manifestations including agitation, hypertension, tachycardia, and psychosis. 3

• Administer benzodiazepines as first-line therapy to manage the sympathomimetic toxidrome 1, 3
• Combine benzodiazepines with nitroglycerin for enhanced control of hypertension and tachycardia when benzodiazepines alone are insufficient 1, 3
• For chest pain with suspected coronary vasospasm, administer sublingual nitroglycerin or intravenous calcium channel blockers (e.g., diltiazem 20 mg IV) as first-line therapy 1

Critical Contraindication

Never administer beta-blockers in acute methamphetamine intoxication showing signs of euphoria, tachycardia, or hypertension, as they cause unopposed alpha-adrenergic stimulation, worsening coronary vasospasm and potentially precipitating myocardial infarction. 1, 3

• Beta-blockers may worsen coronary vasospasm by allowing unopposed alpha-adrenergic stimulation 2, 1
• This contraindication applies only during acute intoxication; patients with a history of methamphetamine use but without signs of acute intoxication can receive standard therapies including beta-blockers if indicated 1

Emergency Department Evaluation

Immediate Assessment

Obtain a 12-lead ECG immediately upon ED arrival to evaluate for cardiac ischemia, arrhythmias, or ST-elevation. 1, 3

• Assess airway, breathing, circulation, and neurological status immediately 1
• Measure cardiac biomarkers (troponin) to assess for myocardial injury 1, 3
• Consider cocaine and methamphetamine use as a cause of acute chest pain symptoms 2

Observation and Monitoring

Patients with ECG changes and normal initial cardiac biomarkers require monitored observation for 9-24 hours, as most methamphetamine-related cardiac complications occur within this timeframe. 1, 3

• A shorter observation period of 9-12 hours with serial troponin measurements at 3,6, and 9 hours may be appropriate in select cases 1
• Immediate angiography is indicated if ST elevation persists despite nitroglycerin and calcium channel blockers, or if cardiac biomarkers are positive 1

Life-Threatening Hyperthermia

For temperature >40°C with continued agitation despite maximal benzodiazepine sedation, proceed immediately to intubation. 3

Indications for Intubation

• Continued agitation despite maximal sedation indicates inability to control metabolic heat production and prevents effective cooling measures 1
• Rhabdomyolysis risk is imminent at high temperatures with ongoing muscle activity, leading to renal failure and death 1
• Seizures are likely given the extreme hyperthermia and sympathomimetic toxicity, requiring airway protection 1

Post-Intubation Management

• Paralyze and sedate with continuous benzodiazepine infusion to eliminate muscle heat production 1
• Implement aggressive cooling measures simultaneously, including chilled saline bolus and external cooling 1
• Treat hyperkalaemia with dextrose and insulin, and calcium chloride 1
• Maintain urine output to prevent myoglobin-induced renal failure with furosemide and mannitol 1

Critical Pitfall

Do not delay intubation waiting for additional benzodiazepines to work, as every minute at high temperatures causes irreversible organ damage. 1

• Mortality approaches 11% in severe sympathomimetic toxicity with hyperthermia 1, 3
• Significant morbidity occurs from rhabdomyolysis, renal failure, seizures, and disseminated intravascular coagulation 1, 3

Chronic Health Effects

Neurotoxicity and Cognitive Impairment

Chronic methamphetamine use is associated with substantial neurotoxicity: 4

• Damage to dopaminergic and serotonergic terminals 5
• Neuronal apoptosis and activated astroglial and microglial cells in the brain 5
• Deficits in attention, memory, and executive functions in humans 5
• Structural changes to the brain 6

Systemic Health Problems

Extended methamphetamine use causes health problems beyond the central nervous system: 4

• Stroke and cardiac arrhythmia 6
• Psychiatric complications: anxiety, insomnia, paranoia, hallucinations 6
• Peripheral vasculopathy, including Raynaud's phenomenon, with potential for digital ulceration and soft tissue breakdown 7
• Serotonin syndrome when combined with other serotonergic drugs (MAOIs, SSRIs, SNRIs, tricyclic antidepressants, fentanyl, lithium, tramadol) 7

Pregnancy and Pediatric Risks

• Methamphetamine use by pregnant women causes growth retardation, premature birth, and developmental disorders in neonates 6
• Children of methamphetamine abusers are at risk of neglect and abuse 6
• Enduring cognitive deficits occur in children exposed to methamphetamine 6

Treatment for Methamphetamine Dependence

Psychosocial Interventions

Optimum treatment for methamphetamine abusers relies on an intensive outpatient setting with three to five visits per week of comprehensive counseling for at least the first three months. 6

Effective psychosocial treatments include: 8

• Cognitive-behavioral therapy improves psychological well-being 8
• The Matrix Model leads to abstinence from methamphetamine and improved psychological well-being 8
• Motivational interviewing increases attendance in treatment 8
• Family therapy improves quality of life and social support 8

Inpatient Treatment

• Inpatient hospitalization may be indicated to treat severe cases of long-term methamphetamine dependence 6
• Long-term treatment usually requires drug rehabilitation and inpatient counseling 9

Mood Stabilization in Active Users

For mood stabilization in patients with active methamphetamine use, valproate offers superior safety compared to lithium. 10

Rationale for Valproate

• Lithium requires strict monitoring of renal function, thyroid function, and serum levels every 3-6 months 10
• Methamphetamine's cardiovascular complications (hypertension, tachycardia, potential for acute coronary syndrome) make lithium's renal effects and need for consistent hydration particularly problematic 10

Implementation

• Start valproate at standard dosing with baseline liver function tests, complete blood count, and pregnancy test 10
• Monitor these parameters every 3-6 months as tolerated by the patient's engagement with care 10
• Target therapeutic serum levels of 50-125 mcg/mL, though clinical response should guide dosing 10
• Avoid lithium monotherapy in active methamphetamine users due to high risk of nonadherence, unpredictable fluid status, and cardiovascular complications 10

Prescription Methamphetamine Warnings

When methamphetamine is prescribed for ADHD (FDA-approved indication): 7

• High potential for abuse and misuse, which can lead to substance use disorder and addiction 7
• Sudden death reported in patients with structural cardiac abnormalities or serious cardiac disease treated with CNS stimulants at recommended ADHD dosages 7
• Avoid use in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease 7
• May exacerbate symptoms in patients with pre-existing psychotic disorder 7
• May induce manic or mixed episodes in patients with bipolar disorder 7
• Associated with weight loss and slowing of growth rate in pediatric patients 7