SAEM Clinical Images Series: Seeing Double


A 53-year-old woman with no significant past medical history presented to the emergency department with a 3-day history of double vision on leftward gaze. She initially presented to urgent care with a chief complaint of chest heaviness and concern that her blood pressure was too high, but was sent to the emergency department for further cardiac and neurological evaluation after her urgent care provider noticed abnormal eye movement. She endorsed mild, intermittent headaches associated with diplopia when looking to the left. However, she denied any blurry vision when looking forward. She denied any trauma or falls.

Vitals: Temp 36.7°C; Heart rate 86 beats/min; Respirations 18 breaths/min; BP 150/82 mmHg; O2 Saturation: 100%

General: No acute distress and appears comfortable. She is alert and oriented.

Eyes: Equal, round and reactive pupils and severely limited adduction of the right eye, all other extraocular movements are normal.

Neuro: All other cranial nerves are intact, normal tone in bilateral upper and lower extremities, normal sensation bilaterally to light touch and pinprick except for mildly decreased sensation to pinprick over right ulnar distribution.

CBC, CMP, EKG, and Troponins were normal.

Lipid panel: Cholesterol 241 (H)

CSF: No oligoclonal bands, Protein 197 (H), Albumin 57 (H), IgG 16.3 (H)

Internuclear ophthalmoplegia (INO) is defined as the inability to adduct the eye due to a lesion in the medial longitudinal fasciculus (MLF) and can be accompanied by nystagmus in the same eye. The two main causes of internuclear ophthalmoplegia are demyelination of the medial longitudinal fasciculus (MLF) from multiple sclerosis (MS) and ischemic cranial nerve damage from stroke. However, a comprehensive list of causes of INO includes: infarction (ischemic stroke), demyelination (MS), tumor, encephalitis, hemorrhage, hydrocephalus, Chiari malformation, infection (Lyme Disease), and trauma. Usually, MS is seen in younger patients where both eyes are affected whereas strokes occur more often in older patients and only one eye is affected.

The therapeutic approach focuses on treating the underlying cause and hence determining the etiology is of immense importance. A brain MRI should be ordered to evaluate for ischemia and demyelination. Proton density imaging is beneficial in identifying MLF lesions in multiple sclerosis. A lumbar puncture can also help rule out infections. A kappa-free light chain antibody test is a faster and less expensive way to test for multiple sclerosis than looking for oligoclonal bands in the CSF.

Given this patient’s relatively young age and vascular risk factors, stroke is highest on the differential. Her brain MRI showed areas of restricted diffusion in the right dorsal medial pons correlating with her exam. It also showed periventricular and subcortical white matter changes which is a non-specific finding in chronic small vessel ischemic changes vs underlying demyelinating disease. This was followed up with an MRI of her spine that demonstrated C5-6 stenosis with associated cord edema and an additional enhancing C3-4 lesion concerning for demyelinating disease. Her lumbar puncture revealed 3 nucleated cells and a protein of 197 but was deemed a traumatic tap. There were no oligoclonal bands. The initial brain MRI findings favored stroke for which she underwent a stroke work-up and was ultimately discharged on aspirin and atorvastatin for secondary prevention. However, due to concern for demyelinating disease, she was also treated with a 3-day course of IV methylprednisolone. Ultimately, she was discharged and asked to come back for a follow-up for repeat brain imaging and evaluation. A recent study showed that patients with unilateral or bilateral INO who experienced symptomatic diplopia were commonly managed by uniocular occlusion. Another case report showed that a young man who presented with acute INO responded rapidly to treatment with IV alteplase when administered within 2 hours of the onset of symptoms and resolution within 15 minutes. A case series revealed that 1 in 5 patients failed to recover from an INO. Hence, it is critical that a definitive workup is carried out to determine the etiology of the INO.

Take-Home Points

  • Brain MRI including DWI is a useful diagnostic tool for INO.
  • Unilateral INO is more frequently related to ischemic/vascular causes whereas bilateral INO is associated with MS.
  • Kim SS, Lee MH, Ji C. Unilateral Internuclear Ophthalmoplegia Following Minor Head Injury. Korean J Neurotrauma. 2022 Oct 24;18(2):329-334. doi: 10.13004/kjnt.2022.18.e64. PMID: 36381451; PMCID: PMC9634317.
  • Mahawish KM, Aravind A. Acute onset internuclear ophthalmoplegia responsive to treatment with intravenous alteplase. N Z Med J. 2020 May 22;133(1515):119-121. PMID: 32438384.
  • Simmons J, Rhodes M. Conservative and Surgical Management of Unilateral and Bilateral Internuclear Ophthalmoplegia (INO)-A Retrospective Analysis. Br Ir Orthopt J. 2022 Nov 7;18(1):152-158. doi: 10.22599/bioj.280. PMID: 36420121; PMCID: PMC9650975.

By |2024-03-16T21:53:50-07:00Mar 22, 2024|Neurology, Ophthalmology, SAEM Clinical Images|

SAEM Clinical Images Series: Intracranial Abnormality

mega cisterna magna

A 26-year-old male with no significant past medical history presented to the ED after slipping on wet pavement and hitting his head on the ground three hours prior. He endorsed a constant, achy 7/10 headache accompanied by nausea and photophobia. He denied vomiting, dizziness, diplopia, loss of consciousness, or seizures. Nothing made it better or worse.

Vitals: BP 101/63; HR 76; RR 14; T 36.7°C

General: Alert and oriented, no acute distress

HEENT: Normocephalic, atraumatic, tenderness elicited over right occipital bone, PERRLA, + photophobia

Neurologic: WNL with no focal motor or sensory deficits appreciated other than photophobia; deep tendon reflexes 2+ throughout, steady gate


This patient has a classic presentation of Mega Cisterna Magna (MCM). MCM is a rare cystic posterior fossa malformation characterized by a 10 mm or larger cisterna magna on midsagittal planes, absent hydrocephalus, and an intact cerebellar vermis. Most cases of MCM are found during prenatal ultrasonography. Adults with isolated MCM are typically asymptomatic and found incidentally on radiographic imaging. No follow-up or treatment is needed.

More than 90% of patients with isolated MCM (such as our patient) have a favorable prognosis and normal development. However, there are multiple conditions that have been found to be associated with MCM. Developmental or cognitive delay occurs in about 8% of patients with MCM, and patients with MCM scored slightly lower than controls when comparing memory, executive functioning, and language fluency. MCM is also associated with other central nervous system (CNS) anomalies; the most common being ventriculomegaly, cerebellar hypoplasia, and arachnoid cysts. Renal defects, such as a horseshoe kidney, are the most common extra-CNS anomalies.

Take-Home Points

  • Mega Cisterna Magna is a cystic posterior fossa malformation typically found on perinatal ultrasonography or incidentally on cranial imaging in asymptomatic patients. MCM is a benign condition with no need to follow up or initiate treatment.
  • Mega Cisterna Magna is associated with developmental and cognitive delay, inferior memory, executive functioning, and verbal fluency, renal defects, and other CNS anomalies.

By |2023-10-26T20:58:31-07:00Oct 27, 2023|Neurology, SAEM Clinical Images|

SAEM Clinical Images Series: A Man with Blurry Vision

cranial nerve

A middle-aged man with a past medical history of hypertension and tobacco use disorder presented to the Emergency Department after evaluation by an ophthalmologist.  He complained of ten days of a right-sided headache and three days of diplopia. He denied eye pain, pain with eye movements, photophobia, and vision loss.

Vitals: Temp 98.4 °F (36.9 °C); BP 122/72; Pulse 90; Resp 16; SpO2 100%

Neuro: Ptosis, “down and out” deviation and pupil dilation of the right eye were noted. Extraocular movements were intact and pupils were reactive to light bilaterally. No other neurologic deficits were observed.


This patient has a partial cranial nerve (CN) III (oculomotor nerve) palsy. CN III is composed of: (a) internal somatic motor fibers that innervate the levator palpebrae superioris (which elevates the upper eyelid) and the medial recti, superior recti, inferior recti, and inferior oblique extraocular muscles, and (b) external parasympathetic fibers innervating the ciliary muscles (involved in accommodation) and sphincter pupillae (involved in pupillary constriction). The presentation of complete isolated CN III palsy generally involves ipsilateral ptosis (due to levator palpebrae paralysis) and “down and out” ocular deviation (due to preservation of superior oblique and lateral rectus function).

The most common etiology of CN III palsy is ischemia of the nerve fibers secondary to diabetes mellitus or hypertension, which preferentially affects the internal somatic fibers that surround the blood supply. This etiology classically results in a pupil-sparing palsy due to preserved function of the external parasympathetic fibers. However, the most feared etiology is an intracranial aneurysm, most commonly a posterior communicating artery aneurysm. This source of external compression classically affects both the internal somatic motor fibers and external parasympathetic fibers, resulting in asymmetric pupil dilation.

Take-Home Points

  • CN III palsy etiologies include ischemia secondary to diabetes mellitus or hypertension, and structural causes, most commonly a posterior communicating artery aneurysm.
  • On exam, complete CN III palsies will present with ipsilateral ptosis, “down and out” ocular deviation, and pupillary dilation. Partial CN III palsies may have a more subtle presentation.
  • New-onset CN III palsy should be evaluated with a CTA to rule out an aneurysm.

  • Biousse V, Newman NJ. Third nerve palsies. Semin Neurol. 2000;20(1):55-74. doi: 10.1055/s-2000-6833. PMID: 10874777. 2. Singh A, Bahuguna C, Nagpal R, Kumar B. Surgical management of third nerve palsy. Oman J Ophthalmol. 2016 May-Aug;9(2):80-6. doi: 10.4103/0974-620X.184509. PMID: 27433033; PMCID: PMC4932800.

Images and cases from the Society of Academic Emergency Medicine (SAEM) Clinical Images Exhibit at the 2021 SAEM Annual Meeting | Copyrighted by SAEM 2021 – all rights reserved. View other cases from this Clinical Image Series on ALiEM.

By |2023-08-14T14:10:25-07:00Aug 18, 2023|Neurology, SAEM Clinical Images|

Phenobarbital as First-Line Medication for Alcohol Withdrawal: Have You Switched From Benzodiazepines Yet?

phenobarbital first line monotherapy for alcohol withdrawal

Are you using phenobarbital instead of benzodiazepines as the first-line monotherapy for patients in alcohol withdrawal in the Emergency Department (ED)? If not, you probably should be. Another old drug for a new indication, right? Well not exactly. Phenobarbital is indeed an older and relatively cheap drug (less than $20 per loading dose) that has gained some press recently for the treatment of acute alcohol withdrawal [1-3].

Why should you consider using phenobarbital as monotherapy rather than benzodiazepines?

Phenobarbital used to be one of the standard treatments for ethanol (EtOH) withdrawal prior to the introduction of benzodiazepines. However, there are key advantages over benzodiazepines.

  1. Phenobarbital has a dual mechanism of action, binding both the GABA receptor and glutamate receptors in the CNS [3]. This helps EtOH withdrawal symptoms by up-regulating GABA activity and down-regulating excitatory glutamate activity.
  2. Phenobarbital has a predictable metabolization with a long half-life of approximately 3-5 days, which allows the drug to self-taper after the initial loading dose and symptom control in the ED [1, 2]. This contrasts the relatively shorter half-life of many available benzodiazepines, which often require more frequent redosing.

Is phenobarbital safe for the treatment of EtOH withdrawal in the ED?

In short, yes. Several studies have indicated that dosing with phenobarbital (PO or IV) is safe and effective at decreasing the need for escalating doses of benzodiazepines for EtOH withdrawal [1-6]. In comparison to benzodiazepines, it demonstrated:

  • Fewer episodes of hypotension and apnea [1-6]
  • Decreased hospital and ICU stay duration in admitted patients [1]
  • Decreased requirement for ICU level care [1]

Dosing regimens

  • Common regimen: 10-15 mg/kg of IDEAL body weight (IBW) IV bolus over 30 minutes and administering 130-260 mg aliquots every 15-30 minutes for persistent symptoms [2]
    • Note that the patient’s IBW may be much lower than the actual body weight.
    • Use the MD Calc calculator for a patient’s IBW
    • Examples based on the average American height:
      • Male: 5’9” –> 71 kg IBW –> phenobarbital 710-1065 mg IV initial bolus
      • Female: 5’4” –> 55 kg IBW –> phenobarbital 550-825 mg IV initial bolus
  • Alternative lower dosing regimen: 130-260 mg IV boluses with repeated dosing as needed [3]
  • Maximum dose
    • No established maximum, but the absolute upper limit for dosing in epilepsy is 20-30 mg/kg [11]
    • Some sources recommend limiting the dose of phenobarbital in alcohol withdrawal to 15 mg/kg/day [3]
  • Adjuncts: Benzodiazepines may be added without decreasing safely [1]

Do patients need phenobarbital dosing adjustments if they have liver dysfunction?

  • Phenobarbital undergoes metabolization primarily in the liver, mostly by CYP2C9 [9].
  • “Dose adjustment” is recommended by the manufacturer in hepatic dysfunction, but no value is provided [10].
    • Since there is no recommended dosing adjustment in patients with cirrhosis and liver dysfunction, a conservative approach starting with the 130 mg boluses and titrating to the minimum effective dose would likely be the safest approach.
  • Clinical pearl: Hepatic encephalopathy is a strong contraindication to phenobarbital [9, 10].
    • Before administering a barbiturate to a cirrhotic patient for EtOH withdrawal, first ensure that hepatic encephalopathy is not the cause of the agitation or altered mental status.
    • Because patients with hepatic encephalopathy experience excess GABA stimulation, they are very sensitive to GABAergic medications (e.g., barbiturates or benzodiazepines).
    • Administration of benzodiazepines or barbiturates to these patients risk inducing a prolonged comatose state.

Is it safe to give phenobarbital to a patient who has already received benzodiazepines?

  • The concern with concurrent phenobarbital and benzodiazepine administration is oversedation. There is a paucity of evidence for this question, although preliminary data suggests that it is safe without significant mortality risk [1].
  • As a corollary, exercise caution when administering phenobarbital to patients at risk for sedation from any cause, such as hepatic encephalopathy, benzodiazepine abuse, and opioid abuse.
  • Suggested approach: If benzodiazepines have already been given, consider using the alternative, more conservative, lower dose regimen protocol (130-260 mg doses) up to 10-15 mg/kg total with close monitoring after every up-titration. Avoid giving benzodiazepines concurrently during the phenobarbital up-titration period to minimize the risk of oversedation and apnea [11].

Which patients treated with phenobarbital require admission?

There is a dearth of evidence about which patients require medical admission in the setting of phenobarbital administration. The American Society of Addiction Medicine has developed a tool to assist providers with disposition planning for patients with alcohol withdrawal syndrome for all-comers (not necessarily those treated with phenobarbital) [2]. Their recommendations are as follows:

  • Outpatient management
    • Able to follow return precautions
    • Likely to continue with alcohol use disorder treatment
    • Supportive living environment
  • Inpatient management
    • Requires frequent physician and nursing intervention
    • Heavy sedation requirements or active delirium tremens
    • Coexisting medical diagnoses that require inpatient management (severe electrolyte anomalies, infections, pancreatitis, hepatic encephalopathy, etc.)
    • History of severe withdrawals, pregnancy, or concurrent medical condition requiring treatment


Phenobarbital has gained significant popularity for use in EtOH withdrawal in the last few years. Several factors make it ideal for use in EtOH withdrawal, primarily its long half-life allowing for a multi-day, self-tapering effect. The most commonly recommended dosing regimen starts with a 10 mg/IBW kg bolus followed by titration every 30 minutes afterwards. Patients in the ED often can be safely phenobarbital-loaded and discharged, assuming hemodynamic stability, normal alertness, and resolution of withdrawal symptoms. More rigorous studies are needed determine dose thresholds that warrant hospital admission.


  1. Rosenson J, Clements C, Simon B, et al. Phenobarbital for Acute Alcohol Withdrawal: A Prospective Randomized Double-blind Placebo-controlled Study. The Journal of Emergency Medicine. 2013;44(3):592-598.e2. doi:10.1016/j.jemermed.2012.07.056. PMID: 22999778
  2. Wolf C, Curry A, Nacht J, Simpson SA. Management of Alcohol Withdrawal in the Emergency Department: Current Perspectives. Open Access Emerg Med. 2020;12:53-65. doi:10.2147/OAEM.S235288. PMID: 32256131
  3. Long D, Long B, Koyfman A. The Emergency Medicine Management of Severe Alcohol Withdrawal. The American Journal of Emergency Medicine. 2017;35(7):1005-1011. doi:10.1016/j.ajem.2017.02.002. PMID: 28188055
  4. Staidle A, Geier C. Phenobarbital and/or Benzodiazepines for Recurrent Alcohol Withdrawal: A Self-Controlled, Retrospective Cohort Study. The American Journal of Emergency Medicine. 2022;54:263-266. doi:10.1016/j.ajem.2022.02.020. PMID: 35219012
  5. Lebin JA, Mudan A, Murphy CE, Wang RC, Smollin CG. Return Encounters in Emergency Department Patients Treated with Phenobarbital Versus Benzodiazepines for Alcohol Withdrawal. J Med Toxicol. 2022;18(1):4-10. doi:10.1007/s13181-021-00863-2. PMID: 34697777
  6. Hendey GW, Dery R, Barnes R, Snowden B, Mentler P. A Prospective, Randomized, Trial of Phenobarbital Versus Benzodiazepines for Acute Alcohol Withdrawal. The American Journal of Emergency Medicine. 2011;29(4):382-385. doi:10.1016/j.ajem.2009.10.010. PMID: 20825805
  7. Hoffman PL, Grant KA, Snell LD, Reinlib L, Iorio K, Tabakoff B. NMDA Receptors: Role in Ethanol Withdrawal Seizures. Annals of the New York Academy of Sciences. 1992;654(1):52-60. doi:10.1111/j.1749-6632.1992.tb25955.x. PMID: 1321581
  8. Young GP, Rores C, Murphy C, Dailey RH. Intravenous Phenobarbital for Alcohol Withdrawal and Convulsions. Annals of Emergency Medicine. 1987;16(8):847-850. doi:10.1016/S0196-0644(87)80520-6. PMID: 3619162
  9. Patsalos PN, Spencer EP, Berry DJ. Therapeutic Drug Monitoring of Antiepileptic Drugs in Epilepsy: A 2018 Update. Therapeutic Drug Monitoring. 2018;40(5):526-548. doi:10.1097/FTD.0000000000000546. PMID: 29957667
  10. Lewis CB, Adams N. Phenobarbital. In: StatPearls. StatPearls Publishing; 2023. Accessed April 16, 2023.
  11. Farkas J. Alcohol withdrawal. EMCrit Project. Published March 29, 2023. Accessed April 18, 2023.
By |2023-05-31T19:25:45-07:00Jun 1, 2023|Neurology, Tox & Medications|

ALiEM AIR Series | Neurology 2022 Module

air series

Welcome to the AIR Neurology 2022 Module! After carefully reviewing all relevant posts in the past 12 months from the top 50 sites of the Social Media Index, the ALiEM AIR Team is proud to present the highest quality online content related to related to neurologic emergencies in the Emergency Department. 5 blog posts met our standard of online excellence and were approved for residency training by the AIR Series Board. More specifically, we identified 2 AIR and 3 Honorable Mentions. We recommend programs give 3 hours of III credit for this module.

AIR Stamp of Approval and Honorable Mentions

In an effort to truly emphasize the highest quality posts, we have 2 subsets of recommended resources. The AIR stamp of approval is awarded only to posts scoring above a strict scoring cut-off of ≥30 points (out of 35 total), based on our scoring instrument. The other subset is for “Honorable Mention” posts. These posts have been flagged by and agreed upon by AIR Board members as worthwhile, accurate, unbiased, and appropriately referenced despite an average score.

Take the AIR Neurology 2022 Module at ALiEMU

Interested in taking the AIR quiz for fun or asynchronous (Individualized Interactive Instruction) credit? Please go to the above link. You will need to create a free, 1-time login account.

Highlighted Quality Posts: Neurologic Emergencies

EMDocsCauda Equina Syndrome: Why do we miss it? How to improve?John H. Priester, MD; Mark Bisanzo, MD13 Jun 2021AIR
EMCritSpinal Epidural AbscessJosh Farkas, MD25 Feb 2022AIR
Clinical MonsterMust Be Blood on the BrainMolly Piccione, DO3 June 2021HM
EMCritNeuro emergencies in pregnancyJosh Farkas, MD23 Feb 2022HM
EMCritNeuro-onc emergenciesJosh Farkas, MD2 June 2022HM

(AIR = Approved Instructional Resource; HM = Honorable Mention)


If you have any questions or comments on the AIR series, or this AIR module, please contact us! More in-depth information regarding the Social Media Index.

Thank you to the Society of Academic Emergency Medicine (SAEM) and the Council of EM Residency Directors (CORD) for jointly sponsoring the AIR Series! We are thrilled to partner with both on shaping the future of medical education.

SAEM Clinical Images Series: Localized Weakness


A 69-year-old Caucasian female with a past medical history of seizures, cerebral vascular accident, and Parkinson’s disease presents by EMS for evaluation of a 30-minute episode of left upper and lower extremity weakness and left facial drooping. The patient complains of a right-sided “migraine-type” headache similar to that experienced with her prior stroke.

Vitals: Temp 36.5°C; BP 186/74; P 74; RR 18; O2 Sat 95%

General: Alert; no acute distress

Skin: Warm; dry; dark red discoloration localized to the left side of face, neck, chest, and upper extremity

HEENT: Normocephalic; left-sided facial droop; pupils are equal round and reactive to light

Cardiovascular: Regular rate and rhythm; no murmurs or gallops

Neurological: Alert and oriented x 4; CN II-XII grossly intact; slow and sluggish speech with left-sided facial droop; motor strength 4/5 LUE and LLE; tremor consistent with Parkinson’s disease

Comprehensive Metabolic Panel (CMP) and Complete Blood Count (CBC) are within normal limits.

Brain Computed Tomography demonstrates chronic atrophy, subcortical calcification, and microvascular ischemia.

Port-wine stain birthmark. This birthmark typically occurs on the forehead, scalp, or around the eye, and is unilateral. It is a manifestation of an overabundance of capillaries near the surface of the skin and exhibits a classic light pink to dark red discoloration.

When located around the eye, port wine stains have been associated with an increased incidence of glaucoma. Large port wine stains on the arm or leg have been associated with extra growth in that limb known as Klippel-Trenaunay syndrome. Port wine staining of the face, forehead, and scalp, when associated with cerebral leptomeningeal angiomas that elicit migraine headaches, seizures, strokes, and intellectual impairment as in this patient, are the classic findings of Sturge-Weber syndrome.

Take-Home Points

  • Sturge-Weber syndrome is the third most prevalent neurocutaneous disorder impacting 1 in 20,000 live births. It is a sporadic congenital neurocutaneous disorder that is caused by somatic activating mutations in the GNAQ gene.
  • Sturge-Weber syndrome is characterized by a facial port-wine stain, leptomeningeal angiomatosis, and glaucoma. Brain involvement can begin early in infancy, and manifests as seizures, strokes, stroke-like episodes, and a variety of neurological impairments.
  • Anticonvulsants, low-dose aspirin, and glaucoma medications are often employed in the management of Sturge-Weber syndrome as well as skin pulse dye laser therapy as desired for cosmesis. The prognosis of this condition depends on the extent of leptomeningeal involvement and the severity of glaucoma.

  • Comi AM. Sturge-Weber syndrome. Handb Clin Neurol. 2015;132:157-68. doi:10.1016/B978-0-444-62702-5.00011-1. PMID: 26564078.
  • Higueros E, Roe E, Granell E, Baselga E. Sturge-Weber Syndrome: A Review. ActasDermosifiliogr. 2017 Jun;108(5):407-417. English, Spanish. doi: 10.1016/ Epub2017 Jan 23. PMID: 28126187.

By |2022-08-18T21:54:43-07:00Aug 22, 2022|Dermatology, Neurology, SAEM Clinical Images|

Are Thrombolytics Safe for Acute Ischemic Strokes in Patients on DOACs?


Direct-acting oral anticoagulants (DOACs), including apixaban, rivaroxaban, edoxaban, and dabigatran, are widely used for various indications and considered first-line therapy for prevention of acute ischemic stroke in patients with nonvalvular atrial fibrillation [1]. The management of acute ischemic stroke in patients on DOACs presents a difficult clinical scenario in the emergency department due to concern for increased risk of hemorrhage. IV thrombolytics (e.g., alteplase, tenecteplase), a mainstay in acute ischemic stroke management, are not recommended in current guidelines for patients whose last DOAC dose was within the last 48 hours [2, 3]. Therefore, patients with an acute ischemic stroke who are compliant with their DOACs are often excluded from guideline recommended therapy. Additionally, as covered in a previous ALiEM post, it is not recommended to reverse anticoagulation status in order to administer a thrombolytic.


The use of IV thrombolytics in patients on DOACs was evaluated by Kam et al in a 2022 study published in JAMA [4]. This retrospective analysis included 163,038 patients from the AHA/ASA Get With The Guidelines-Stroke registry with acute ischemic stroke who received IV alteplase within 4.5 hours of symptom onset. Of the total number of patients, only 2207 had documented use of a DOAC within the last 7 days, with 25 of these patients reporting DOAC use within 48 hours. Patients on warfarin or other anticoagulants were excluded. The primary outcome was symptomatic intracranial hemorrhage (ICH) within 36 hours of IV alteplase administration. After adjusting for clinical factors, the rate of symptomatic ICH was not significantly different between patients taking DOACs and those not on anticoagulation (3.7% vs. 3.2%, adjusted OR 0.88, 95% CI 0.70 to 1.10). However, when stratified based on time from last DOAC dose, patients who took their DOAC 0-48 hours prior had an 8% rate of symptomatic ICH compared to 3.2% among those not on DOACs. Furthermore, the rate of any alteplase complication was 12% vs. 6% in those taking DOACs within 48 hours vs. no DOAC.


  • The population at highest risk for bleeding is patients who took a DOAC within the last 48 hours, and this study only included 25 such patients.
    • A similar study tried to answer the same question for warfarin patients with an INR between 1.5-1.7. They also failed to include enough patients to make any definitive conclusions. [5]
  • Timing from the last DOAC dose was given as a range, with the majority of patients reporting use sometime within the last 7 days. It has been established in current AHA/ASA guidelines that receipt of DOACs past 48 hours prior is considered safe for thrombolytic administration, and if the included institutions were following current recommendations, thrombolytics were likely administered mostly to patients outside the 48-hour window.
  • Large potential for selection bias, since it was reported that almost 23,000 patients on DOACs from the original registry (who were otherwise eligible) did not receive thrombolytics.
  • Not clear how patients were determined to be on DOACs or if the authors were able to confirm this in unresponsive/intubated/deceased patients retrospectively. This could have resulted in DOAC patients being included in the non-DOAC group, which could have falsely evened-out the bleeding rates.

Bottom Line

  • The management of acute ischemic stroke in patients receiving prior anticoagulation presents a challenging clinical scenario.
  • Studies to date fail to include enough patients to evaluate the true risk of bleeding.
  • This study supports the current guideline recommendation to avoid alteplase in patients receiving a DOAC within 0-48 hours due to the increased risk of intracranial hemorrhage.

Want to learn more about EM Pharmacology?

Read other articles in the EM Pharm Pearls Series and find previous pearls on the PharmERToxguy site.


  1. January CT, Wann LS, Calkins H, et al. 2019 AHA/ACC/HRS focused update of the 2014 AHA/ACC/HRS guideline for the management of patients with atrial fibrillation. Published correction appears in Circulation. 2019;140(6):e285. Circulation. 2019;140(2):e125-e151. doi: 10.1161/CIR.0000000000000665. PMID: 30686041.
  2. Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines for the early management of acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2019;50(12):e344-e418. doi: 10.1161/STR.0000000000000211. PMID: 31662037.
  3. Berge E, Whiteley W, Audebert H, et al. European Stroke Organisation (ESO) guidelines on intravenous thrombolysis for acute ischaemic stroke. Eur Stroke J. 2021;6(1):I-LXII. doi: 10.1177/2396987321989865. PMID: 33817340.
  4. Kam W, Holmes DN, Hernandez AF, et al. Association of Recent Use of Non-Vitamin K Antagonist Oral Anticoagulants With Intracranial Hemorrhage Among Patients With Acute Ischemic Stroke Treated With Alteplase. JAMA. 2022;327(8):760-771. doi:10.1001/jama.2022.0948. doi: 10.1001/jama.2022.0948. PMID: 35143601.
  5. Xian Y, Liang L, Smith EE, et al. Risks of intracranial hemorrhage among patients with acute ischemic stroke receiving warfarin and treated with intravenous tissue plasminogen activator. JAMA. 2012;307(24):2600-2608. doi:10.1001/jama.2012.6756. doi: 10.1001/jama.2012.6756. PMID: 22735429.


Primary author:

Jessica Mason, PharmD

PGY-2 Emergency Medicine Pharmacy Resident

Massachusetts General Hospital

Go to Top