Reserved for hyperthermia refractory to sedation and cooling
Cardiovascular management
Hypertension and tachycardia
Adequate sedation is primary intervention
Benzodiazepines often resolve hypertension and tachycardia
Persistent hypertension after sedation
Nicardipine IV
5 mg/hr infusion, titrate by 2.5 mg/hr every 5–15 minutes
Maximum 15 mg/hr
Clevidipine IV
1–2 mg/hr infusion, titrate by doubling every 90 seconds
Maximum 32 mg/hr
Phentolamine IV
5 mg IV bolus, repeat as needed
Alpha-adrenergic antagonist — addresses mechanism
Avoid long-acting antihypertensives
Risk of hemodynamic collapse as drug wears off
Beta-blocker caution
Pure beta-blockers generally contraindicated
Risk of unopposed alpha-adrenergic stimulation
May worsen hypertension paradoxically
If beta-blockade required, use agents with alpha-1 antagonism
Labetalol or carvedilol preferred
Coronary vasospasm management
Nitroglycerin sublingual or IV
For suspected vasospasm-induced ischemia
Calcium channel blockers
Diltiazem or verapamil for vasospasm
Takotsubo cardiomyopathy with cardiogenic shock
Intra-aortic balloon pump consideration
Cardiogenic shock unresponsive to vasopressors
Veno-arterial ECMO
Refractory cardiogenic shock
Often resolves in days to weeks with supportive care
Cardiac arrest management
Standard ACLS protocol
CPR and defibrillation per AHA guidelines
Extracorporeal CPR (ECPR) consideration
AHA 2025 guidelines support ECLS in toxicological arrest
Transfer to ECMO-capable center if indicated
Rhabdomyolysis treatment
IV fluid resuscitation
Aggressive crystalloid hydration
Normal saline or lactated Ringer solution
Initial bolus 1–2 L IV for volume depletion
Maintenance targeting UOP 1–3 mL/kg/hr
Urine output monitoring
Foley catheter placement mandatory
Adjust rate based on UOP response
Urinary alkalinization
Sodium bicarbonate infusion (controversial)
Some guidelines suggest targeting urine pH > 6.5
Reduces myoglobin precipitation in tubules
Avoid if pH > 7.45 or hypocalcemia present
Renal replacement therapy
If AKI progresses to oliguria unresponsive to fluids
Nephrology consultation
Continuous RRT preferred in hemodynamically unstable patients
Seizure management
First-line antiepileptic
Benzodiazepines
Lorazepam 0.1 mg/kg IV (up to 4 mg per dose)
Diazepam 0.15 mg/kg IV (up to 10 mg per dose)
Midazolam 10 mg IM if no IV access
Second-line antiepileptic
Phenobarbital
20 mg/kg IV loading dose
Maximum infusion rate 60 mg/min
Propofol
1–2 mg/kg IV induction dose then infusion
Requires intubation
Special Populations
Pregnancy
Maternal considerations
Sympathomimetic effects in pregnancy
Uterine vasoconstriction risk
Placental abruption risk from hypertension
Preterm labor from catecholamine surge
Fetal monitoring
Continuous fetal heart rate monitoring if viable gestation
Obstetrics consultation for all pregnant patients
Treatment modifications in pregnancy
Benzodiazepines
Generally acceptable in acute life-threatening agitation
Neonatal respiratory depression risk if near delivery
Risk-benefit strongly favors treatment in excited delirium
Antipsychotics
Haloperidol limited data in pregnancy
Use lowest effective dose for shortest duration
Cooling measures
External cooling safe in pregnancy
Hyperthermia itself is teratogenic in first trimester
Avoid
Dantrolene in pregnancy (Category C, limited data)
Phentolamine with caution — uterine vasodilation possible
Geriatric
Physiologic considerations
Cardiovascular vulnerability
Higher risk of dysrhythmias from catecholamine surge
Pre-existing coronary artery disease increases MI risk
Reduced cardiac reserve for tachycardia tolerance
Thermoregulatory impairment
Reduced sweating capacity
Higher baseline risk of hyperthermia complications
Renal impairment
Lower baseline GFR increases AKI severity
More aggressive monitoring of renal function required
Treatment modifications in geriatric patients
Benzodiazepine dosing
Start with lower doses (midazolam 2.5–5 mg IM)
Increased sensitivity to respiratory depression
Monitor closely for paradoxical agitation
Antipsychotics
Use with caution — QTc prolongation risk higher in elderly
Baseline ECG before antipsychotic administration if feasible
Fluid resuscitation
Cautious fluid administration with cardiac history
Risk of fluid overload and pulmonary edema
Pediatrics
Epidemiology in pediatric population
Flakka use among high school seniors documented
Palamar et al. 2019 — US national prevalence data
Adolescent use driven by low cost and availability
Accidental exposure in young children also reported
Ingestion of discarded drug material
Clinical presentation differences
Symptoms similar to adults
Agitation, tachycardia, hyperthermia
Lower dose required for toxicity
Weight-based threshold lower
Higher risk of seizures at lower doses
Pediatric dosing
Midazolam
0.1–0.2 mg/kg IM or IV (maximum 10 mg per dose)
Repeat every 5 minutes as needed
Lorazepam
0.05–0.1 mg/kg IV (maximum 4 mg per dose)
Cooling
External cooling thresholds same as adults (> 40°C)
Weight-based fluid resuscitation for rhabdomyolysis
Urine output target 1–3 mL/kg/hr
Pediatric toxicology consultation mandatory
Poison Control Center: 1-800-222-1222
Background
Epidemiology
Substance classification and prevalence
α-PVP (alpha-pyrrolidinovalerophenone)
Second-generation synthetic cathinone
Street name: Flakka, gravel
Schedule I controlled substance in the United States
Prevalence data
Significant epidemic documented in South Florida 2014–2015
Re-emergent use documented in Europe and Asia 2020s
Low cost (approximately $5 per dose) drives availability
User demographics
Young males predominate (median age 27–32 years)
Approximately 79% male in case series
Chemsex context increasingly documented
Mortality and morbidity
Mortality rate approximately 5% in severe cases
Leading cause of death: refractory hyperthermia
Cardiac dysrhythmia as second cause
Polydrug use rate high
85.6% co-use with synthetic cannabinoids
Polydrug use complicates management and increases mortality
Pathophysiology
Mechanism of action
Monoamine transporter reuptake inhibition
Potent dopamine transporter (DAT) inhibitor
Potent norepinephrine transporter (NET) inhibitor
Negligible serotonin transporter (SERT) activity
Distinguishes from MDMA and mephedrone which have SERT activity
Comparative potency
More effective reinforcer than cocaine in animal models
More effective reinforcer than methamphetamine
Higher abuse liability score than classical stimulants
Clinical toxicological consequences
Dopamine excess
Psychosis, hallucinations, paranoia
Hyperthermia via hypothalamic dysregulation
Reward pathway dysregulation and high addiction potential
Norepinephrine excess
Tachycardia and hypertension
Peripheral vasoconstriction
Coronary vasospasm
Sympathomimetic toxidrome
Hyperthermia mechanism
Psychomotor agitation generates heat
Impaired heat dissipation from vasoconstriction
Central hypothalamic temperature setpoint dysregulation
Rhabdomyolysis mechanism
Sustained muscle hyperactivity from agitation
Direct catecholamine-mediated muscle damage
Hyperthermia-induced enzyme denaturation
Pharmacokinetics
Onset of action
Intranasal: peak at approximately 40 minutes
Smoked or IV: faster onset, minutes
Duration of effect
3–5 hours for intranasal route
Variable depending on dose and route
Metabolism
Hepatic metabolism via CYP enzymes
Urinary excretion of metabolites
Not detected on standard immunoassay drug screens
Confirmation by LC-MS/MS required
Therapeutic Considerations
Evidence base for treatment
Benzodiazepines
ACEP and AHA guidelines support benzodiazepines as first-line
No specific antidote available for α-PVP
Treatment is supportive and symptomatic
Cooling interventions
Ice water immersion shown superior to other methods
Target cooling rate > 0.15°C/min associated with survival benefit
Class I recommendation level from emergency medicine literature
Physical restraints
Associated with sudden death — positional asphyxia
Should not be maintained without concurrent chemical sedation
Minimize duration of restraint
ASAM/AAAP stimulant use disorder guidelines
No FDA-approved pharmacotherapy for stimulant use disorder
Behavioral interventions remain cornerstone of treatment
Contingency management has strongest evidence base
Referral to addiction medicine services
Connect all patients to treatment resources at discharge
Harm reduction counseling regarding drug screen limitations
Substance use disorder screening tools
AUDIT-C for alcohol
DAST-10 for drug abuse
Cardiotoxicity considerations
QTc prolongation
Direct drug effect and indirect via antipsychotic co-administration
Continuous ECG monitoring during acute phase
Vasospasm and acute MI
Catecholamine-mediated coronary vasospasm
No role for thrombolytics if vasospasm mechanism suspected
Takotsubo cardiomyopathy
Catecholamine-mediated stress cardiomyopathy
Typically reversible with supportive care
Patient Discharge Instructions
copy discharge instructions
Discharge instructions for Flakka (alpha-PVP) toxicity
What happened
You were treated in the emergency department for toxic effects from a synthetic stimulant drug called Flakka (alpha-PVP)
This drug is extremely dangerous and can cause life-threatening heart problems, seizures, dangerously high body temperature, and kidney damage
Medications prescribed
Take all prescribed medications exactly as directed
Do not take other stimulants, cocaine, or amphetamines with any medications
Activity restrictions
Rest at home for 24–48 hours
Avoid all stimulant substances including Flakka, cocaine, methamphetamine, and similar drugs
Do not drive or operate machinery for at least 24 hours
Return to emergency department immediately for
Chest pain or pressure
Difficulty breathing
Seizures or convulsions
Confusion or agitation that is worsening
Dark brown or tea-colored urine
Decreased urine output
Fever over 38.5°C (101.3°F)
Thoughts of hurting yourself or others
Follow-up appointments
Primary care physician within 48–72 hours
Addiction medicine consultation recommended
Psychiatry if mood or thought symptoms persist
Resources
Poison Control Center: 1-800-222-1222 (available 24 hours)
Substance abuse helpline: SAMHSA 1-800-662-4357
Standard urine drug tests do not detect Flakka — inform healthcare providers of actual substance used
References
Guidelines and key sources
Primary references
Kolesnikova TO et al. DARK Classics in Chemical Neuroscience: Alpha-Pyrrolidinovalerophenone (Flakka). ACS Chemical Neuroscience. 2019. PMID: 30384587
Mechanism of action, abuse liability, and comparative potency data
Nobrega L, Dinis-Oliveira RJ. The Synthetic Cathinone Alpha-Pyrrolidinovalerophenone (alpha-PVP): Pharmacokinetic and Pharmacodynamic Clinical and Forensic Aspects. Drug Metabolism Reviews. 2018. PMID: 29540067
Pharmacokinetics, clinical presentation, and management
Umebachi R et al. Clinical Characteristics of Alpha-Pyrrolidinovalerophenone (alpha-PVP) Poisoning. Clinical Toxicology. 2016. PMID: 27227375
Severity classification, laboratory findings prevalence data
Beck O et al. Toxicity Evaluation of Alpha-PVP: Results From Intoxication Cases Within the STRIDA Project. Clinical Toxicology. 2016. PMID: 27412885
European epidemiology and clinical outcomes
De la Rosa G et al. Acute Pharmacological Effects of Alpha-PVP in Humans: A Naturalistic Observational Study. Frontiers in Pharmacology. 2025. PMID: 40672373
Recent human pharmacological data
Society guidelines
Lavonas EJ et al. 2023 AHA Focused Update on Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning. Circulation. 2023
ACLS in toxicological emergencies
Cao D et al. Part 10: Adult and Pediatric Special Circumstances of Resuscitation: 2025 AHA Guidelines for CPR and Emergency Cardiovascular Care. Circulation. 2025
Updated toxicological cardiac arrest management
The ASAM/AAAP Clinical Practice Guideline on the Management of Stimulant Use Disorder. Journal of Addiction Medicine. 2024. PMC: 11105801
Stimulant use disorder treatment and referral standards
Sandau KE et al. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings. AHA Scientific Statement. Circulation. 2017
Cardiac monitoring recommendations
Additional references
Palamar JJ et al. Flakka Use Among High School Seniors in the United States. Drug and Alcohol Dependence. 2019. PMID: 30709657
US adolescent prevalence data
Richards JR et al. Treatment of Toxicity From Amphetamines, Related Derivatives, and Analogues: A Systematic Clinical Review. Drug and Alcohol Dependence. 2015. PMID: 25724076
Systematic review of sympathomimetic toxidrome treatment
Banks ML et al. Synthetic Cathinones (Bath Salts). Journal of Emergency Medicine. 2014. PMID: 24565885
Radaelli D et al. Synthetic Cannabinoids and Cathinones Cardiotoxicity: Facts and Perspectives. Current Neuropharmacology. 2021. PMID: 33845747
Cardiovascular toxicity mechanisms
Cheng HC et al. Fatal Polydrug Intoxication Involving Synthetic Cathinones in Taiwan. Journal of Emergency Medicine. 2026. PMID: 41719591
Fatal polydrug cases and emergency management
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.