Seizures and Hyperthermia Associated with Poisoning or Drug Overdose

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Transcript Seizures and Hyperthermia Associated with Poisoning or Drug Overdose

Seizures and Hyperthermia Associated with Poisoning or Drug Overdose

Kent R. Olson, MD, FACEP, FACMT Medical Director, San Francisco Division California Poison Control System University of California, San Francisco California Poison Control System – San Francisco Division

Causes of Status Epilepticus in the ED

1980-1989 Urban SF Hospital – 154 pts

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Anticonvulsant drug withdrawal: 39

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Alcohol-related: 39

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Drug Toxicity: 14 (9%)

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CNS infection: 12

Lowenstein DH & Alldredge BK et al: Neurol 1993; 43

California Poison Control System – San Francisco Division

Outline

Causes of drug-induced seizures (“drug” = drug or poison)

Consequences and complications of drug-induced seizures

Anticonvulsants for drug-induced seizures

Management of drug-induced hyperthermia California Poison Control System – San Francisco Division

Case

A 27 yo man was admitted with an unknown drug overdose, unresponsive but breathing. Pupils 5 mm. Absent bowel sounds. Frequent jerking movements.

BP 120/80, HR 100/min ECG: California Poison Control System – San Francisco Division

California Poison Control System – San Francisco Division

Case (continued)

Shortly after admission he developed recurrent generalized seizures. With the onset of seizures, the QRS interval increased to 0.20 sec. The BP fell to 70 mm systolic, and dopamine and norepinephrine were given. California Poison Control System – San Francisco Division

California Poison Control System – San Francisco Division

Case (continued)

Three hours after admission, the rectal temperature was noted to be 107 F.

Despite intensive supportive care, he developed multi-organ failure and died.

California Poison Control System – San Francisco Division

Complications of Drug-Induced Seizures

Hypoxemia

Shock

Hyperthermia

Rhabdomyolysis Brain Damage

Metabolic acidosis

Other drug-specific complications California Poison Control System – San Francisco Division

Common Causes of Drug-Induced Seizures

Cocaine, amphetamines, other stimulants

Tricyclic antidepressants

Other antidepressants & antipsychotics

Diphenhydramine

Isoniazid

Many others

Olson KR et al: Am J Emerg Med 1993; 11:565-568

California Poison Control System – San Francisco Division

35% 30% 25%

Calls to the SF Poison Center about drug related seizures

20% 15% 10% 5% 1981 1989 2006 0% TC A s Is on ia zi d Th eo ph yl lin e D ip he nh yd ra m in e S tim ul an ts B up ro pi on N S ew SR a Is nt ic on vu ls an ts

California Poison Control System – San Francisco Division

Treatment of Drug-Induced Seizures

ABCD’s:

Airway

Breathing

Circulation

Dextrose

Anticonvulsants

Specific antidote, if available

Cooling measures California Poison Control System – San Francisco Division

Antiepileptic-Drug Therapy for Status Epilepticus.

From: Lowenstein DH & Alldredge BK: NEJM 1998; 338:970 California Poison Control System – San Francisco Division

Anticonvulsants for Drug-Induced Seizures Benzodiazepine Specific antidote, if available Phenytoin?

Phenobarbital Pentobarbital, Propofol, or Midazolam California Poison Control System – San Francisco Division

Tricyclic and Related Antidepressants

Cardiotoxicity often worsened by seizures

Use bicarb to restore/maintain pH > 7.4

Muscle twitching, absent sweating increase risk of hyperthermia

Consider neuromuscular paralysis

No specific antidote for seizures

Do not use physostigmine, phenytoin California Poison Control System – San Francisco Division

Cocaine & Amphetamines

Seizures are usually brief, self-limited

Prolonged or multiple seizures suggests complications such as intracranial hemorrhage, head injury, hyperthermia, etc

Treatment:

Sedation

Anticonvulsants if needed

Cooling measures California Poison Control System – San Francisco Division

Case

16 year old took 200 Benadryl ™ tablets Agitation, somnolence, seizure Wide complex QRS California Poison Control System – San Francisco Division

Antihistamines

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Diphenhydramine is most common

Seizures usually brief, self-limited

Accompanied by mild-moderate anticholinergic findings

Massive diphenhydramine OD may cause TCA-like cardiotoxicity Treatment:

Anticonvulsants if needed

Bicarbonate for TCA-like QRS prolongation California Poison Control System – San Francisco Division

Isoniazid (INH)

Common TB drug

Marked lactic acidosis

pH 6.8-6.9 common after even 1-2 brief seizures

Treatment of seizures:

Diazepam often effective

Pyridoxine is specific antidote - give 1 gm for each gm OD; 5 gm if dose unknown California Poison Control System – San Francisco Division

Pyridoxine for INH overdose

INH ( ) Pyridoxal-5 phosphate + Glutamic Acid Decarboxylase (+) Pyridoxine (Vit B-6) Glutamate GABA California Poison Control System – San Francisco Division

Case

28 year old man had a seizure and was brought to the ER by a friend Tox screen (+) for amphetamines But, he denied amphetamine use

He had borrowed one of his friend’s pills, which had been obtained from…

California Poison Control System – San Francisco Division

California Poison Control System – San Francisco Division

Zyban ™

Bupropion

Antidepressant = Wellbutrin ™

Well-known cause of seizures

Can occur even at therapeutic antidepressant doses

Can give false-positive result for amphetamines on tox screening California Poison Control System – San Francisco Division

Other antidepressants & etc

All the SSRI’s have been associated with seizures in OD - Venlafaxine - Fluoxetine - Citalopram Newer and older antipsychotics also California Poison Control System – San Francisco Division

New Anticonvulsants Causing Seizures

Lamotrigine

Topiramate

Tiagabine

One case report of status epilepticus resistant to benzos, controlled with propofol Haney ST et al: Internet J Toxicol 2004, 1(2) California Poison Control System – San Francisco Division

Case of the hot taquitos

5 people with new onset seizures None had prior sz Utox negative All had eaten taquitos purchased from a convenience store California Poison Control System – San Francisco Division

Case (cont.)

Leftover taquitos were found to contain the pesticide endrin Organochlorine pesticides

DDT

Endrin

Aldrin

Lindane California Poison Control System – San Francisco Division

Another case

36 year old man ingested some Elston Gopher Getter ™ Bait Developed “seizures” (diffuse tonic spasms) but remained awake during and between events California Poison Control System – San Francisco Division

Strychnine

Popular poison for thousands of years

Strychnos nux vomica

Not true “seizures” as CNS is minimally affected (until victim is hypoxic) Spinal cord glycine receptor action

Inhibits inhibitory action of glycine on spinal cord reflex motor response

Similar to tetanus California Poison Control System – San Francisco Division

Final “hot” case

21 yo released from a drug rehab facility for a home visit Became agitated, combative, shoving his brother, talking nonsense

GM seizure HR 160/min, T 105.7 F Skin red, dry Incontinent California Poison Control System – San Francisco Division

Hot dude, cont.

Utox negative LP: meningitis!!

California Poison Control System – San Francisco Division

“Rule outs”

“A T O M I C” A: alcohol withdrawal T: trauma/tomography O: overdose M: metabolic I: infection C: carbon monoxide California Poison Control System – San Francisco Division

Hyperthermia (Temp > 40 C)

Heat Production Basal metabolism Heat Dissipation Vasodilation Muscle activity CORE TEMP Conduction/Radiation Ambient temperature Evaporation California Poison Control System – San Francisco Division

Drug-Induced Hyperthermia - Mechanisms

Muscle hyperactivity:

Cocaine, Amphetamines

Seizures

Reduced sweating:

Anticholinergics

Increased cellular metabolism:

Salicylates

Dintrophenol California Poison Control System – San Francisco Division

Complications of Hyperthermia

Hypotension due to vasodilation, sweating, MI

Brain injury from hypotension, hyperthermia, prolonged seizures, hypoxemia

Coagulopathy due to reduced production of clotting factors, and endothelial wall damage

Rhabdomyolysis caused by muscle hyperactivity, hyperthermia, and reduced muscle blood flow

Renal failure from myoglobinuria, hyperthermia California Poison Control System – San Francisco Division

Malignant Hyperthermia

Specific disorder of muscle cell

Most commonly associated with general anesthetics (succinylcholine, halothane)

Rigidity, acidosis, hyperthermia

Specific treatment:

Dantrolene

NM paralysis is not effective California Poison Control System – San Francisco Division

Neuroleptic Malignant Syndrome

Associated with chronic antipsychotic use (haloperidol, etc.)

Mechanism is central dopamine blockade

Lead-pipe rigidity, diaphoresis, altered mental status, hyperthermia

Specific treatment:

Bromocriptine?

NM paralysis California Poison Control System – San Francisco Division

Serotonin Syndrome

SSRI OD or added to MAO inhibitors:

also: MAOI + Meperidine, Trazodone, Tryptophan, Dextromethorphan, others

Confusion, agitation, increased muscle tone (especially lower extr. clonus)

Specific Treatment:

Cyproheptadine?

NM paralysis California Poison Control System – San Francisco Division

Anticholinergic Syndrome

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Dilated pupils, tachycardia, decreased bowel sounds, urinary retention Agitation, delirium, or coma Muscular twitching common Absent sweating Treatment:

Physostigmine? (with caution)

Usual cooling measures California Poison Control System – San Francisco Division

Management of Hyperthermia

Act quickly to prevent brain damage/death

ABC’s

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Protect airway, assist ventilation Give supplemental oxygen IV fluid bolus if hypotensive Dextrose if needed based on bedside BS Anticonvulsants if seizures are present California Poison Control System – San Francisco Division

Management of Hyperthermia (cont.)

Rapid external cooling

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Strip clothing Tepid sponging + fanning Do not use ice packs

T > 106 F or persistent sz or muscle rigidity

Neuromuscular paralysis

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Most rapidly effective Rx Use non-depolarizing agent California Poison Control System – San Francisco Division

Management of Hyperthermia (cont.)

persistent muscle rigidity despite NM paralysis

Suspect muscle defect (malignant hyperthermia)

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Give Dantrolene Continue external cooling California Poison Control System – San Francisco Division

Evaporative Cooling

Weiner JS, Khogali M: A physiological body-cooling unit for treatment of heat stroke. Lancet. 1980;1(8167):507-9.

California Poison Control System – San Francisco Division

Some References

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Alvarez FG, Guntupalli KK. Isoniazid overdose: four case reports and review of the literature. Intensive Care Med. 1995 Aug;21(8):641-4.

Beaubien A et al. Antagonism of imipramine poisoning by anticonvulsants in the rat. Toxicol Appl Pharmacol 1976;38:1 –6 Blake KV et al: Relative efficacy of phenytoin and phenobarbital for the prevention of theophylline-induced seizures in mice. Ann Emerg Med. 1988 Oct;17(10):1024-8 Centers for Disease Control (CDC). Endrin poisoning associated with taquito ingestion--California. MMWR Morb Mortal Wkly Rep. 1989 May 19;38(19):345-7. Clark RF, Vance MV. Massive diphenhydramine poisoning resulting in a wide-complex tachycardia: successful treatment with sodium bicarbonate.

Haney ST et al: Tiagabine-induced status epilepticus responds to propofol. Internet J Toxicol 2004, 1(2) Lowenstein DH, Alldredge BK. Status epilepticus at an urban public hospital in the 1980s. Neurology 1993;43:483-488 Lowenstein DH & Alldredge BK: Status epilepticus. NEJM 1998; 338:970 Mayron R, Ruiz E. Phenytoin:does it reverse tricyclic antidepressant induced cardiac conduction abnormalities? Ann Emerg Med 1986;15:876 –80 Olson KR, Benowitz NL. Environmental and drug-induced hyperthermia. Pathophysiology, recognition, and management. Emerg Med Clin North Am. 1984 Aug;2(3):459-74. Olson KR et al. Seizures associated with poisoning and drug overdose. Am J Emerg Med. 1994 May;12(3):392-5. Stecker MM et al. Treatment of refractory status epilepticus with propofol: clinical and pharmacokinetic findings. Epilepsia 1998;39:18-26 Yarbrough BE, Wood JP. Isoniazid overdose treated with high-dose pyridoxine. Ann Emerg Med. 1983 May;12(5):303-5. Wood DM et al: Case report: Survival after deliberate strychnine self-poisoning, with toxicokinetic data. it Care. 2002; 6(5): 456 –459 Ann Emerg Med. 1992 Mar;21(3):318-21.

California Poison Control System – San Francisco Division