Category: Pharmacology & Therapeutics
Keywords: hyperkalemia, calcium, cardiac conduction, resting membrane potential (PubMed Search)
Posted: 9/11/2024 by Alicia Pycraft
(Emailed: 9/12/2024)
(Updated: 9/12/2024)
Click here to contact Alicia Pycraft
The benefits of calcium treatment for hyperkalemia have historically been attributed to “membrane stabilization,” as it has been hypothesized to restore cardiac resting membrane potential. However, the true mechanism by which calcium improves cardiac function in this setting remains unclear. This has led to inconsistencies in the clinical threshold for treating hyperkalemia with calcium.
Piktel et al. recently conducted an experimental study investigating the adverse electrophysiologic effects of hyperkalemia and therapeutic effects of calcium treatment in isolated canine myocytes using ex vivo tissue and in vivo cellular techniques.
Key study findings:
Effects of hyperkalemia:
Effects of calcium treatment in the setting of hyperkalemia:
Limitation:
Bottom line: Findings of this study suggest that calcium's beneficial effects in hyperkalemia are not attributed to “membrane stabilization,” but rather to restoration of conduction velocity through L-type calcium channels and subsequent narrowing of the QRS complex. This supports calcium treatment in hyperkalemia when the ECG shows conduction slowing and QRS widening.
Piktel JS, Wan X, Kouk S, Laurita KR, wilson LD. Beneficial effect of calcium treatment for hyperkalemia is not due to “membrane stabilization” Crit Care Med. 2024; 52(00): 1-10.
Category: Pharmacology & Therapeutics
Keywords: Hyponatremia, Correction, 3% Sodium Chloride, Hypertonic Saline (PubMed Search)
Posted: 7/11/2024 by Wesley Oliver
Click here to contact Wesley Oliver
At our institution we have developed a guideline for the use of hypertonic saline in hyponatremia.
Administration of 3% sodium chloride for acute or symptomatic hyponatremia
Acute hyponatremia with severe symptoms
Acute hyponatremia with moderate symptoms
Hyponatremia Fluid Rate Calculations (**Be Careful with Online Calculators**)
FYI: 3% Sodium Chloride (1.95 mL/mEq; 513 mEq/1 L); 0.9% Sodium Chloride (6.5 mL/mEq; 154 mEq/1 L)
Equations for Calculations
***See Visual Diagnosis for an Example with Calculations***
Example:
70 kg male patient with a current sodium of 115 mEq/L (not hyperglycemic)
3% Sodium Chloride
0.9% Sodium Chloride
**Popular Online Calculator Using Same Example**
3% sodium chloride: 54 mL/hr
0.9% sodium chloride: 551 mL/hr
Be aware that the default setting of the calculator is to correct by 12 mEq/L over 24 hours leading to larger rates of infusion.
Adult Hypertonic Aline for Use in Hyponatremia, Medication Use Guideline. University of Maryland Medical System. Accessed July 2024.
Hoorn EJ, Zietse R. Diagnosis and treatment of hyponatremia: compilation of the guidelines.
JASN. 2017; 28(5):1340-1349.
Jones GN, Bode L, Riha H et al. Safety of continuous peripheral infusion of 3% sodium chloride solution in neurocritical care patients. Am J Crit Care. 2017; 26(1): 37-42.
Sodium chloride preparations. Lexi-Drugs. Lexicomp. Wolters Kluwer Health, Inc. Riverwoods, IL. Available at: http://online.lexi.com. Accessed June 2018.
Spasovski G, Vanholder R, Allolio B, et al. Clinical practice guideline on diagnosis and treatment of hyponatremia. Intensive Care Med. 2014; 40:320-331.
Verbalis JG, Goldsmith SR, Greenberg A, et al. Diagnosis, Evaluation and Treatment of Hyponatremia: Expert Panel Recommendations. Amer J Med. 2013; 126:S1-S42.
Category: Pharmacology & Therapeutics
Keywords: alcohol use disorder, phenobarbital, naloxone, treatment (PubMed Search)
Posted: 6/23/2024 by Robert Flint, MD
(Updated: 10/6/2024)
Click here to contact Robert Flint, MD
Two recommendations from the recent GRACE 4 publication in Academic Emergency Medicine to consider:
1. Use phenobarbital along with benzodiazepines in patients with moderate to severe alcohol withdrawal. The evidence isn’t robust but is positive when compared to benzos alone.
2. Adults with alcohol use disorder can benefit from anti-craving medications such as naloxone and gabapentin at time of discharge.
Guidelines for Reasonable and Appropriate Care in the Emergency Department (GRACE-4): Alcohol use disorder and cannabinoid hyperemesis syndrome management in the emergency department Bjug Borgundvaag PhD, MD, CCFP(EM), Fernanda Bellolio MD, MSc, Isabelle Miles MD, Evan S. Schwarz MD, Sameer Sharif MD, MSc, Mark K. Su MD, MPH, Kevin Baumgartner MD, David B. Liss MD, Hasan Sheikh MD, MPA, Jody Vogel MD, MSc, MSW, Emily B. Austin MD, Suneel Upadhye MD, MSc, Michelle Klaiman MD, FRCPC, DABAM, Robert Vellend, Anna Munkley, Christopher R. Carpenter MD, MSc
First published: 15 May 2024
Academic Emergency Medicine https://doi.org/10.1111/acem.14911
Category: Pharmacology & Therapeutics
Keywords: Pharmacology, Toxicology, Acetaminophen, Acetylcysteine, NAC (PubMed Search)
Posted: 6/13/2024 by Matthew Poremba
Click here to contact Matthew Poremba
A panel comprised of 21 participants selected by four clinical toxicology societies (America’s Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) sought to develop consensus guidelines for management of acetaminophen poisoning in the US and Canada. Highlights from this framework include:
Acetylcysteine Stopping Criteria
A common misconception is that acetylcysteine is administered for 21 hours then discontinued. The consensus statement codifies the practice of reassessing the patient at the end of the acetylcysteine infusion and only stopping acetylcysteine if all of the following criteria are met:
Ingestion of Extended-Release Acetaminophen Products
Extended release acetaminophen products are available on the US market. Management is largely the same as for instant release acetaminophen except for several exceptions:
Management of Repeated Supratherapeutic Acetaminophen Ingestion
When a patient presents following repeated acetaminophen ingestions over a period of greater than 24 hours the Matthew-Romack nomogram is no longer applicable for guiding decisions regarding treatment with acetylcysteine. The consensus statement recommends initiating treatment in this scenario if the patient’s acetaminophen concentration is > 20 mcg/mL or if patient’s AST/ALT are abnormal.
Final Thoughts:
These guidelines will function as a useful reference and officially codify a general framework with evidence-based recommendations for the management of acetaminophen poisoning. As always, a poison center or clinical toxicologist should be consulted for any complicated or serious acetaminophen poisoning.
Dart, Richard C et al. “Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement.” JAMA network open vol. 6,8 e2327739. 1 Aug. 2023, doi:10.1001/jamanetworkopen.2023.27739
Category: Pharmacology & Therapeutics
Keywords: myasthenia gravis, myasthenic crisis, exacerbation, drugs to avoid (PubMed Search)
Posted: 5/9/2024 by Alicia Pycraft
Click here to contact Alicia Pycraft
Myasthenia gravis (MG) is an autoimmune neuromuscular disorder that affects an estimated 14 to 20 patients per 100,000 in the United States. Most patients with MG have autoantibodies against acetylcholine receptors (AChRs), which disrupt neuromuscular transmission through downregulation, destruction, blocking of AChRs or disrupting receptors in the postsynaptic membrane.
Several medications may worsen MG or precipitate myasthenic crisis, however, incidence is difficult to describe as literature is largely limited to case reports and there is often presence of other confounding factors. There are two proposed mechanisms for medications to cause or exacerbate MG:
Several medications commonly used in the emergency department are known to impair neuromuscular transmission and may induce or worsen MG. The following medications should be avoided, or used with extreme caution in patients with MG*:
*This list contains several common medications utilized in the emergency department, but is not an all-inclusive list of medications that may exacerbate MG. Please refer to the reference section for additional information.
Category: Pharmacology & Therapeutics
Keywords: naloxone, opioid (PubMed Search)
Posted: 4/11/2024 by Ashley Martinelli
(Updated: 10/6/2024)
Click here to contact Ashley Martinelli
Naloxone is given frequently in the emergency department to improve the respiratory rate in patients with suspected or known opioid ingestion. In order to minimize the risk of severe opioid withdrawal (nausea, vomiting, diarrhea, anxiety, piloerection, sweating, agitation, etc.), consider diluting naloxone and administering small aliquots of 0.04-0.08mg at a time. This requires IV access and a patient with a present, but low respiratory rate.
Dilution instructions:
Supplies:
Instructions:
Administer 1 -2 mL (0.04 – 0.08 mg) naloxone every 2 minutes and assess response.
Don't forget to prescribe/give naloxone upon discharge from the emergency department.
Category: Pharmacology & Therapeutics
Keywords: Bactrim, skin and soft tissue infections, Streptococcus spp (PubMed Search)
Posted: 3/14/2024 by Wesley Oliver
Click here to contact Wesley Oliver
MYTH: Bactrim cannot be used as monotherapy for nonpurulent skin and soft tissue infections.
Not True!
Organisms of concern: Streptococcus spp.
Here’s why:
TRUTH: Bactrim CAN be used as monotherapy for nonpurulent skin and soft tissue infections.
Prepared by Rianna Fedora, PharmD on 2/26/24
SMX-TMP Myth Buster Inservice-65f3561ae6df0.pdf (58 Kb)
Category: Pharmacology & Therapeutics
Keywords: Necrotizing Fasciitis, Necrotizing Soft Tissue Infection, Skin and Soft Tissue Infection, clindamycin, linezolid, NSTI (PubMed Search)
Posted: 2/8/2024 by Matthew Poremba
Click here to contact Matthew Poremba
Empiric antimicrobial treatment for necrotizing soft tissue infections (NSTIs) should include coverage of a wide range of pathogens including Staphylococcus spp, Streptococcus spp, anaerobic bacteria and gram negative bacteria. Treatment should also include an agent that suppresses toxin production by group A Streptococcus (GAS), with the Infectious Diseases Society of America (IDSA) guidelines recommending clindamycin plus penicillin for treatment of GAS causing necrotizing fasciitis and toxic shock syndrome. A typical empiric NSTI regimen would be vancomycin plus clindamycin plus piperacillin-tazobactam.
Linezolid is an appealing alternative to clindamycin and vancomycin, as it has anti-toxin effects via inhibition of exotoxin expression, potent in vitro activity against Streptococcus spp, activity against methicillin-resistant Staphylococcus aureus (MRSA), and potential for less adverse effects than clindamycin plus vancomycin. Several recent studies have looked at using linezolid in lieu of clindamycin plus vancomycin when treating NSTIs.
Published Studies:
Dorazio and colleagues published a retrospective single center study compared 62 matched pairs of patients who received linezolid vs. clindamycin plus vancomycin as part of their NSTI treatment.
Heil and colleagues published a retrospective single center cohort study examined patients who received either linezolid (n = 29) or clindamycin (n = 26) for treatment invasive soft tissue infection or necrotizing fasciitis with GAS isolated from blood and/or tissue.
Lehman and colleagues published a retrospective single center study compared patients who received linezolid (n = 21) versus clindamycin plus vancomycin (n = 28) in addition to gram-negative and anaerobic coverage for empiric treatment of NSTIs.
Bottom Line:
When added to an agent with good gram negative and anaerobic coverage (i.e. piperacillin-tazobactam), linezolid may be a more viable option for coverage of MRSA and GAS toxin production during empiric NSTI treatment when compared to clindamycin plus vancomycin. This is largely due to a more favorable side effect profile.
Category: Pharmacology & Therapeutics
Keywords: COVID-19, Paxlovid (PubMed Search)
Posted: 1/11/2024 by Alicia Pycraft
Click here to contact Alicia Pycraft
Nirmatrelvir-ritonavir (Paxlovid™) is a combination of two protease inhibitors used for the treatment of mild-moderate symptomatic COVID-19. Nirmatrelvir inhibits the SARS-CoV2 main protease, and ritonavir inhibits metabolism of nirmatrelvir, acting as a “booster” to increase nirmatrelvir concentrations.
The EPIC-HR trial, which included non-hospitalized adults with mild-moderate COVID-19 who were unvaccinated and at risk of progressing to severe disease, showed an 89% reduction in COVID-19-related hospitalization or 28-day all-cause mortality in patients treated with nirmatrelvir-ritonavir compared to placebo. The efficacy rates in this trial were similar to remdesivir (87% relative risk reduction), and greater than molnupiravir (31% relative risk reduction), two alternative agents used for treatment of mild-moderate COVID-19. However, these three agents have never been directly compared. Nirmatrelvir-ritonavir was initially approved by the FDA under Emergency Use Authorization (EUA), but is now fully FDA-approved as of May 2023.
Which patients benefit?
Drug-Drug Interactions:
Dosing:
Common side effects:
Bottom Line: Paxlovid is appropriate for patients with symptomatic mild-moderate COVID-19 with risk factors for progression to severe disease. Ask your pharmacist for assistance evaluating drug-drug interactions!
Additional resources:
Category: Pharmacology & Therapeutics
Posted: 12/30/2023 by Robert Flint, MD
(Updated: 10/6/2024)
Click here to contact Robert Flint, MD
For the agitated geriatric patient, if verbal deescalation, distraction, and providing a safe quiet area do not work and you require chemical sedation use oral antipsychotics first. Follow this with IV or IM antipsychotics. Avoid benzodiazepines due to often worsening delirium or respiratory depression. For dosing, start low and go slow.
Emergency Medicine Clinics VOLUME 42, ISSUE 1, P135-149, FEBRUARY 2024
Michelle A. Fischer, MD, MPH Monica Corsetti, MD
Published:July 31, 2023DOI:https://doi.org/10.1016/j.emc.2023.06.016
Category: Pharmacology & Therapeutics
Posted: 12/14/2023 by Ashley Martinelli
(Updated: 10/6/2024)
Click here to contact Ashley Martinelli
Bottom Line: Droperidol is an effective alternative to haloperidol in the treatment of gastroparesis although most patients will also receive prokinetic agents as well such as metoclopramide. It may also have some analgesic benefit.
Prior studies have demonstrated the efficacy and safety of haloperidol in the management of gastroparesis. A recent retrospective study was conducted to assess the impact of droperidol as it is an effective antiemetic similar to haloperidol.
This study enrolled 233 patients. Visits were matched with their most recent ED visit > 7 prior where droperidol was not administered.
Most patients were female, 51% African American, and the median age was 40. Doses ranged from 0.625 mg – 2.5 mg with the most common dose being 1.25 mg.
Results:
Stirrup N, Jones G, Arthus J, Lewis Z. Droperidol undermining gastroparesis symptoms (DRUGS) in the emergency department. American Journal of Emergency Medicine. 2024;75:42-45.
Category: Pharmacology & Therapeutics
Keywords: epinephrine, anaphylaxis, allergy, digital ischemia, phentolamine, nitroglycerin ointment, terbutaline (PubMed Search)
Posted: 10/12/2023 by Alicia Pycraft
Click here to contact Alicia Pycraft
Background: It is estimated that nearly 6% of U.S. adults and children report having a food allergy.1,2 Epinephrine autoinjectors are used to provide life-saving pre-hospital treatment for patients experiencing anaphylaxis in the community, but can have serious consequences if administered incorrectly. Accidental finger-stick injuries with epinephrine auto-injector can result in significant pain and ischemia due to vasoconstriction and decreased blood flow to the digit. Treatments for digital epinephrine injection include supportive care, topical vasodilators, and injectable vasodilators.3
Supportive care3,4:
Category: Pharmacology & Therapeutics
Keywords: DOAC, apixaban, rivaroxaban, loading dose (PubMed Search)
Posted: 9/14/2023 by Wesley Oliver
(Updated: 10/6/2024)
Click here to contact Wesley Oliver
DOACs (dabigatran*, apixaban, rivaroxaban) each have different dosing strategies based on indication and patient characteristics. While there is no official term for the doses, the higher initial doses for apixaban (10 mg BID for 7 days) and rivaroxaban (15 mg BID for 21 days) for the treatment of venous thromboembolism (VTE) are commonly referred to as “loading doses.” However, the term “loading dose” is actually a misnomer.
Loading doses are used to reach therapeutic drug levels quicker with medications such as vancomycin and phenytoin/fosphenytoin. However, this is not the purpose of the higher initial doses of apixaban and rivaroxaban. The purpose of the higher doses is to provide increased levels of anticoagulation during the acute phase of VTE when patients are hypercoagulable. For this reason, VTE and heparin-induced thrombocytopenia are the only indications where a higher dose is used initially, all other indications start with the standard dose. The difference in duration of these higher doses between apixaban (7 days) and rivaroxaban (21 days) are due to the durations used in trials by the drug company, versus any pharmacokinetic reasons.
To apply this concept:
Apixaban/Rivaroxaban: For the treatment of VTE, a higher dose is only required for the initial 7- (apixaban) or 21-day period (rivaroxaban). After this period, if there is any interruption in therapy, the standard dose can be restarted because therapeutic levels are rapidly achieved and higher doses are not needed outside of the acute phase.
One caveat to this would be if the patient developed a new VTE while therapy is interrupted, in which case another period of the higher dosing could be considered.
*Remember: Dabigatran cannot be used for initial treatment of VTE and must be started only after at least 5 days of a parenteral anticoagulant. (Dabigatran and the parenteral anticoagulant should not be overlapped).
References
Eliquis (apixaban) [prescribing information]. Princeton, NJ: Bristol-Myers Squibb Company; April 2021.
Pradaxa (dabigatran) [prescribing information]. Ridgefield, CT: Boehringer Ingelheim Pharmaceuticals Inc; June 2021.
Xarelto (rivaroxaban) [prescribing information]. Titusville, NJ: Janssen Pharmaceuticals Inc; February 2023.
Category: Pharmacology & Therapeutics
Keywords: Tenecteplase, Pulmonary Embolism, Cardiac Arrest (PubMed Search)
Posted: 8/10/2023 by Wesley Oliver
Click here to contact Wesley Oliver
ACLS guidelines state that thrombolytics may be considered for suspected pulmonary embolism during cardiac arrest. There is limited data supporting the recommendation; however, it is noted that the benefits likely outweigh the risks. There is also no consensus on the appropriate thrombolytic timing, drug, or dose.
Our institution recently implemented the use of tenecteplase for acute ischemic stroke, ST-elevation myocardial infarction (STEMI), and pulmonary embolism (PE). When using tenecteplase for suspected PE during cardiac arrest, we use the same weight-based dose used for STEMIs. We include a label on the outside of the tenecteplase box that lists all the doses for the various indications.
Tenecteplase Dose
<60 kg: 30 mg
≥60 to <70 kg: 35 mg
≥70 to <80 kg: 40 mg
≥80 to <90 kg: 45 mg
≥90 kg: 50 mg
The tenecteplase dose is administered as an IV bolus over 5 seconds.
There is also limited data for the duration of CPR after thrombolytic administration, with no recommendations being made in most literature. Our current institutional guidelines recommend to consider continuing CPR for 60-90 minutes before resuscitation efforts are terminated. The only guideline that makes any mention of duration of CPR is the European Resuscitation Council Guidelines 2021, which makes the same recommendation.
Berg KM, Soar J, Andersen LW, et al. Adult Advanced Life Support: 2020 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science with Treatment Recommendations. Circulation. 2020; 142(suppl 1):S92-139.
Lavonas EJ, Drennan IR, Gabrielli A, et al. Part 10: special circumstances of resuscitation: 2015 American Heart Association guidelines update for cardiopulmonary resuscitation and emergency cardiovascular care. Circulation. 2015; 132(suppl 2):S501-S518.
Lott C, Truhlá A, Alfonzo A, et al; ERC Special Circumstances Writing Group Collaborators. European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances. Resuscitation. 2021 Apr;161:152-219.
TNKase (tenecteplase) [prescribing information]. South San Francisco, CA: Genentech; March 2023.
Category: Pharmacology & Therapeutics
Keywords: Calcium, Massive transfusion protocol, Citrate, Blood products (PubMed Search)
Posted: 7/13/2023 by Wesley Oliver
(Updated: 10/6/2024)
Click here to contact Wesley Oliver
Citrate is an anticoagulant added to blood products to maintain stability for storage. With the administration of large volumes of blood products, citrate binds to ionized calcium, which can cause hypocalcemia. Evidence for specific calcium administration during massive transfusion protocols is limited; however, a proposed strategy has been to administer calcium gluconate 2 grams for every 2-4 units of red blood cells.
Robinson, et al. performed a retrospective analysis attempting to determine the optimal Citrate:Ca ratio (a novel ratio created for this study) to reduce 30-day mortality. They did not find any differences in mortality; however, they found a Citrate:Ca ratio of 2-3 produced a normalized ionized calcium level with 24 hours of a massive transfusion protocol.
Based on their calculations, this would equate to supplementing 1 g of calcium gluconate for every 3 units of red blood cells given.
***Reminder: Based on the amount of elemental calcium in each gram of calcium gluconate (4.7 mEq) and calcium chloride (13.6 mEq); 3 g calcium gluconate=1 g calcium chloride.***
Bottom Line: Supplementing with calcium gluconate 1 g for every 3 units of red blood cells should be sufficient to maintain normal ionized calcium levels after a massive transfusion protocol.
Robinson A, Rech MA, DeChristopher PJ, Vaughn A, Rubino J, Bannister E, Moore ME, Chang K. Defining the optimal calcium repletion dosing in patients requiring activation of massive transfusion protocol. Am J Emerg Med. 2023 May 13;70:96-100.
Category: Pharmacology & Therapeutics
Keywords: nitroglycerin, administration set, drug sorption, PVC tubing, polyethylene, SCAPE (PubMed Search)
Posted: 6/8/2023 by Matthew Poremba
(Updated: 10/6/2024)
Click here to contact Matthew Poremba
Nitroglycerin easily migrates into polyvinyl chloride (PVC), a plastic commonly used in intravenous tubing due to its flexibility and low cost. A slow rate of flow and long tubing length increase the loss of nitroglycerin. While using less absorptive tubing (i.e. polyethylene or polypropylene) when administering nitroglycerin is recommended, most published clinical studies looking at nitroglycerin have used PVC tubing.
A 1989 study compared nitroglycerin delivery through PVC tubing and low sorbing tubing at various concentrations and flow rates.1 Samples were obtained from the nitroglycerin bottle and the distal end of the tubing at several time points.
A 2018 study enrolled 8 volunteers to receive nitroglycerin infusions through PVC tubing and low sorbing polyolefin tubing.2
Bottom Line: Most studies evaluating nitroglycerin use in various clinical scenarios have used PVC tubing. Doses based on use with PVC tubing may be too high when using less absorptive tubing. Employing more conservative dosing strategies when using low sorbing tubing can help mitigate the risk of adverse effects (i.e. hypotension, headache).
Category: Pharmacology & Therapeutics
Keywords: contraception (PubMed Search)
Posted: 5/11/2023 by Ashley Martinelli
(Updated: 10/6/2024)
Click here to contact Ashley Martinelli
Emergency contraception is highly effective at preventing unwanted pregnancies and has been on the market for 20+ years.
Levonogestrel (LNG) 1.5 mg PO x 1 dose (OTC Available)
Ulipristal acetate (UPA) 30 mg PO x 1 dose (Requires RX)
Original studies with LNG was estimated to prevent up to 80% of expected pregnancies. In the subsequent trials that brought UPA to the market and compared the two medications, LNG prevented 69% (95% CI, 46-82%) and 52.2% (95% CI, 25.1-69.5%).
While pregnancy rates are low with both options there is concern with patients of higher weight/BMI that the effectiveness of levonorgestrel decreases as weight rises. One large study of over 1700 patients specifically noted that a weight > 75 kg was associated with up to 6.5% pregnancy rate (95% CI 3.1-11.5) compared to 1.4% (95% CI 0.5-3.0) in patients weighing 65-75 kg. Patients weighing > 85 kg had similarly high rates at 5.7% (95% CI 2.9-10.0).
The cost difference is minimal between products, especially when considering costs associated with treatment failures and subsequent need for care- the largest difference is with respect to access as LNG is OTC and UPA requires an RX. Either can be administered in an ED setting as long as they are on formulary.
ACOG also recommends that ulipristal be utilized for it higher overall efficacy compared to levonorgestrel.
Consider:
For patients above 75 kg, ulipristal can be used as first line emergency contraception for up to 5 days following unprotected intercourse.
Patients < 75 kg and < 72 hours following unprotected intercourse can use levonorgestrel or ulipristal as an appropriate emergency contraception method.
Patients < 75 kg and 72-120 hours following unprotected intercourse should use ulipristal due to its efficacy beyond 72 hours.
Kapp N, Abitbol JL, Mathe H, et al. Effect of body weight and BMI on the efficacy of levonogestrel emergency contraception. Contraception. 2015;91(2):97-104.
Emergency contraception. Practice Bulletin No. 152. American College of Obstetricians and Gynecologists. Obstet Gynecol 2015;126:e1–11
Category: Pharmacology & Therapeutics
Keywords: Myasthenia gravis, Myasthenic crisis, neuromuscular blocker, paralytic, rocuronium, vecuronium, succinylcholine (PubMed Search)
Posted: 4/1/2023 by Matthew Poremba
Click here to contact Matthew Poremba
Myasthenia gravis is an autoimmune disease of the neuromuscular junction, most commonly due to antibodies attacking acetylcholine receptors in the postsynaptic membrane. Up to 30% of patients with myasthenia gravis will experience a myasthenic crisis during their disease course. If rapid sequence intubation is indicated, the unique characteristics of this patient population must be considered in the event use of a paralytic is necessary. All paralytic agents can be expected to last significantly longer, and an unpredictable response may be seen with depolarizing agents - therefore non-depolarizing agents are preferred in this population.
Non-Depolarizing Agents (Rocuronium, Vecuronium)
Depolarizing Agents (Succinylcholine)
Roper J, Fleming ME, Long B, Koyfman A. Myasthenia Gravis and Crisis: Evaluation and Management in the Emergency Department. J Emerg Med. 2017;53(6):843-853.
Abel, Mark, and James B Eisenkraft. “Anesthetic implications of myasthenia gravis.” The Mount Sinai journal of medicine, New York vol. 69,1-2 (2002): 31-7.
Category: Pharmacology & Therapeutics
Keywords: atrial fibrillation, atrial flutter, diltiazem, calcium (PubMed Search)
Posted: 3/3/2023 by Ashley Martinelli
(Emailed: 3/4/2023)
(Updated: 10/6/2024)
Click here to contact Ashley Martinelli
Non-dihydropyridine calcium channel blockers, verapamil and diltiazem, can induce hypotension when administered intravenously (IV) in approximately 4% of patients. It has previously been taught that administering IV calcium before administering these medications may prevent the hypotension. Previously, this theory was tested for verapamil and found success with reducing hypotension. Only one study has been done exclusively with diltiazem and it found no benefit.
In a new multicenter retrospective cohort study of adults in the ED, patients were randomized into two groups: those who received diltiazem alone and those who received calcium with diltiazem for atrial fibrillation/atrial flutter (AF/AFL) with a HR ≥ 120 bpm. Patients were excluded if they required electrocardioversion, had other agents prior to diltiazem, incomplete information, were pregnant or incarcerated. The primary outcome was change in SBP 60 minutes (+/-30 minutes) after diltiazem administration.
Baseline characteristics: 73 year old, equal male:female, predominantly white patients. 40% had new onset AF/AFL and the initial HR was 140 in both groups. There were 198 patients in the diltiazem group and 56 patients in the combination group. Notably, patients in the combination group had a lower presenting SBP 109 (101-121) vs 123 (114-132) P<0.0001 which matches classical teaching for when to consider calcium use. Additionally, patients in the combination group received a lower diltiazem dose of 10mg vs 15mg in the monotherapy group p=0.004 with both group receiving doses lower than the standard 0.25 mg/kg dosing recommendation.
Outcomes:
Take Home Point:
Administration of IV calcium may not be as beneficial as previously thought to prevent hypotension induced by diltiazem administration. This particular study is confounded by the relatively low doses of diltiazem overall, but utilizing a lower dosing strategy in patients with low SBP is a reasonable safety strategy.
Rossi N, Allen B, Hailu K, et al. Impact of intravenous calcium with diltiazem for atrial fibrillation/flutter in the emergency department. Am J Emergency Medicine. 2023;64:57-61.
Category: Pharmacology & Therapeutics
Keywords: Angioedema, ACE-inhibitor, C1-Esterase Inhibitor, ACEi, C1INH, Berinert (PubMed Search)
Posted: 2/3/2023 by Wesley Oliver
(Emailed: 2/4/2023)
(Updated: 2/4/2023)
Click here to contact Wesley Oliver
ACE-inhibitor (ACEi) induced angioedema is mediated by bradykinin and there are no proven medications for the treatment of this disease. Theoretically, a C1-esterase inhibitor (C1INH) could be beneficial; however, data has not demonstrated any efficacy for these agents.
Strassen et al. recently published a double-blind, randomized, controlled, multicenter trial of 30 patients comparing C1NH (Brand Name: Berinert) to placebo. In addition to standard treatment, a dose of C1INH (Berinert) 20 IU/kg or placebo (0.95% NaCl) was administered intravenously.
The primary endpoint was the time to complete resolution of signs and symptoms of edema (TCER). When compared to placebo, the original primary analysis demonstrated that the placebo arm (15 hours) resolved faster than the C1INH arm (24 hours, p=0.046).
This study is further evidence against the use of C1INH for ACE-inhibitor induced angioedema. The primary focus in the treatment of ACEi induced angioedema should continue to be airway management.
For reference, at our institution we have both C1INH (Berinert) and icatibant on formulary and they are restricted to only being used for acute hereditary angioedema attacks and cannot be used for ACEi induced angioedema.
Strassen U, et al. Efficacy of human C1 esterase inhibitor concentrate for treatment of ACE-inhibitor induced angioedema. Am J Emerg Med. 2023;64:121-128.
Wilkerson RG, Martinelli AN, Oliver WD. Treatment of angioedema induced by angiotensin-converting enzyme inhibitor [letter]. J Emerg Med. 2018;55:132-133.