112 for an ambulance." There is no specific antidote for<unk> . Emergency treatment of<unk> -associated high body temperature consists of giving a benzodiazepine and physical cooling. Immediate administration of aspirin is required for patients reporting<unk> -associated chest pain. Cooling is best accomplished with tepid water misting and cooling with a fan. Antipyretics (e.g., paracetamol) have no effect in lowering high temperature because<unk>  is an muscarinic receptor agonist. The chest pain, high blood pressure, and increased heart rate caused by<unk>  may be also treated with benzodiazepines. Multiple and escalating dose of benzodiazepines may be necessary to achieve effect, which increases risk of over-sedation and respiratory depression. A review of<unk>  cardiovascular toxicity found benzodiazepines may not always reliably lower heart rate and blood pressure. Lidocaine and intravenous lipid emulsion have been successfully used for serious ventricular tachyarrhythmias in several case reports. People who are agitated are best treated with benzodiazepines, though antipsychotics such as haloperidol and olanzapine may also be useful. The alpha-2 agonist dexmedetomidine may also be useful for agitation, but effects on heart rate and blood pressure are variable based on several studies and case reports. Vasodilators Nitric-oxide mediated vasodilators, such as nitroglycerin and nitroprusside, are effective at lowering blood pressure and reversing coronary arterial vasoconstriction, but not heart rate. Nitroglycerin is useful for<unk> -induced chest pain, but the possibility of reflex tachycardia must be considered. Alpha blockers Alpha-blockers such as phentolamine have been recommended and may be used to treat<unk> -induced hypertension and coronary arterial vasoconstriction, but these agents do not reduce heart rate. Furthermore, phentolamine is rarely used, not readily available in many emergency departments, and many present-day clinicians are unfamiliar with its use. Beta blockers Although the use of beta blockers is still controversial, notwithstanding decades of practice, despite research papers and systematic reviews on this subject (more details are in the next section), the intravenous racemic mixture of labetalol, a non-selective β blocker and selective α1 blocker is recommended for treating concomitant hypertension and tachycardia. Furthermore, the use of labetolol is approved by a AHA/ACC guideline for people who have used<unk>  and methamphetamine with unstable angina/non-STEMI. A relative contraindication to the use of beta-blockers is still evident in some guidelines for the treatment of<unk>  toxicity despite limited evidence. The phenomenon of “unopposed alpha-stimulation,” in which blood pressure increases or coronary artery vasoconstriction worsens after blockade of beta-2 vasodilation in people using<unk> , is controversial. This rarely-encountered and unpredictable adverse effect has resulted in some clinicians advocating for an absolute contraindication of all beta-blockers, including specific, non-specific, and mixed. Many clinicians have disregarded this dogma and administer beta-blockers for<unk> -related chest pain and acute coronary syndrome, especially when there is demand ischemia from uncontrolled tachycardia. Of the 1,744 people in the aforementioned systematic review, only 7 adverse events were from putative cases of “unopposed alpha-stimulation” due to propranolol (n=3), esmolol (n=3), and metoprolol (n=1). Some detractors of beta-blockers for<unk> -induced chest pain have cited minimal acute mortality and the short half-life of the medication, making it unnecessary to aggressively treat any associated tachycardia and hypertension. However, the long-term effect of<unk>  use and development of heart failure, with early mortality, high morbidity, and tremendous demand on hospital utilization should be taken under consideration. Calcium channel blockers Calcium channel blockers may also be used to treat hypertension and coronary arterial vasoconstriction, but fail to lower tachycardia based on all<unk> -related studies. Non-dihydropyridine calcium channels blockers such as diltiazem and verapamil are preferable, as dihydropyridine agents such as nifedipine have much higher risk of reflex tachycardia (however, clinicians can prevent reflex tachycardia by administering beta-blockers some minutes before using the latter class of CCBs).
Cocaine intoxication
Hypertensive encephalopathy
Carbamate poisoning
Benzodiazepine overdose
Nicotine withdrawal
Alcohol withdrawal syndrome
Benzodiazepine withdrawal syndrome
Opioid overdose