Antibiotics

My elderly patient with UTI and E. coli bacteremia is ready to be switched from IV to oral antibiotic. Can I consider an oral beta-lactam in place of a fluoroquinolone or trimethoprim-sulfamethoxazole to complete an adequate course of antibiotic therapy at home.

FA Manian MD, MPH, , , , , , , , Leave a comment

Although oral fluoroquinolones (FQs) and trimethoprim-sulfamethoxazole (TMP-SMX) have been routinely recommended as step-down therapy for treatment of Enterobacterales bacteremia owing to their high bioavailability, increasing evidence suggests that beta-lactam (BL) antibiotics (particularly those with high bioavailability, such as cephalexin) are as effective without the attendant adverse risks associated with FQs—with increasing FDA warnings—and TMP-SMX.1,2

In the largest study to date involving a retrospective review of over 4,000 cases of Enterobacterales UTI-associated bacteremia (eg, E. coli, Proteus spp., Klebsiella spp) in Veterans Affairs hospitals, no significant difference in the main outcome (composite of 30-day all cause mortality or 30-day recurrent bacteremia) was found between the oral beta-lactam and FQ/TMP-SMX groups (4.4% vs 3.0%, respectively); additionally, when examined separately, no significant difference in mortality (3.0% vs 2.6%) or recurrent bacteremia (1.5% vs 0.4%) was found. 1

A meta-analysis of 8 retrospective studies (2019) also failed to find a significant difference in mortality or recurrent bacteremia between BLs and FQs or TMP-SMX groups; it did find a higher odds of any recurrent infection, however (5.5% vs 2.0% (O.R. 2.06, 1.18-3.61). 2

Before selecting an antibiotic, however, it’s important to recall that not all oral BLs are  created equal, with some having better bioavailability than others.   More specifically, it may not be common knowledge that cephalexin (“Keflex”), a commonly prescribed and inexpensive cephalosporin with great safety profile, has 90-100% bioavailability, rivaling those of FQs or TMP-SMX.

 Of interest, in a subset of patients who received cephalexin as step-down therapy (n=245) in the VA study above, the outcomes were nearly identical to those who received FQ or TMP-SMX, with a 30-d recurrent bacteremia of 0% and a 30-day mortality of 2% (vs 0.4% and 2.5% for ciprofloxacin and 1.0% and 2.4% for TMP-STX, respectively). Of note nearly one-half of the cephalexin group received a higher dose of 500 mg 4x/day, with the rest receiving less frequent dosing. 

These findings makes one wonder whether suboptimal oral BL dosing may not have contributed to the discrepant results from earlier studies suggesting the superiority of FQs or TMP-SMX over oral BLs as step-down therapy. 1,2

 

Bonus Pearl: Did you know that cephalexin may be given up to 4 gm/day in 4 divided doses with 90% of the drug excreted unchanged in the urine? 3

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References

  1. Sutton JD, Stevens VW, Chang NCN, Khader K, et al. Oral beta-lactam antibiotics vs fluoroquinolones or trimethoprim-sulfamethoxazole for definite treatment of Enterobacterales bacteremia from a urine source. JAMA Network Open 2020;3 (10):e20220166. Oral β-Lactam Antibiotics vs Fluoroquinolones or Trimethoprim-Sulfamethoxazole for Definitive Treatment of Enterobacterales Bacteremia From a Urine Source – PubMed (nih.gov)
  2. Punjabi C, Tien V, Meng L, et al. Oral fluoroquinolone or trimethoprim-sulfamethoxazole vs beta-lactams as step-down therapy for Enterobacteriaceae bacteremia: systematic review and meta-analysis. Open Forum Infect Dis 2019;6:ofz364 doi:10.1.1093/ofid/ofz364   https://pubmed.ncbi.nlm.nih.gov/31412127/
  3. Herman TF, Hasmi MF. Cephalexin. StatPearls (internet). https://www.ncbi.nlm.nih.gov/books/NBK549780/ Accessed July 10, 2022.

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Mercy Hospital-St. Louis, Massachusetts General Hospital, Harvard Catalyst, Harvard University, their affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

My elderly patient with UTI and E. coli bacteremia is ready to be switched from IV to oral antibiotic. Can I consider an oral beta-lactam in place of a fluoroquinolone or trimethoprim-sulfamethoxazole to complete an adequate course of antibiotic therapy at home.

Why are antibiotics routinely administered in patients with cirrhosis and upper gastrointestinal (GI) bleed?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , 1 Comment

Antibiotic prophylaxis in patients with cirrhosis and upper gastrointestinal bleed (UGIB) reduce bacterial infections, all-cause mortality, bacterial infection, mortality, rebleeding events and hospitalization.1

A 2011 Cochrane meta-analysis involving 12 trials comparing antibiotic prophylaxis to no prophylaxis or placebo found reduction in bacterial infection (RR 0.35, 95% C.I., 0.26-0.47) and overall mortality (RR 0.79, 95% C.I. 0.63-0.98). It also found a significant reduction in rebleeding and days of hospitalization, based on more limited data. Trials in this meta-analysis involved a variety of antibiotics, including norfloxacin, ciprofloxacin, cefazolin, cefotaxime, ceftriaxone and ampicillin-sulbactam. 1

So why is ceftriaxone the often-favored bacterial prophylaxis in UGIB? First, infections in cirrhotic patients often originate from bacterial translocation through the GI tract with aerobic gram-negative GI flora expected to be susceptible to ceftriaxone.2 Second, the emerging quinolone resistance among aerobic Gram-negative bacteria 2 and frequent use of ciprofloxacin for prophylaxis against spontaneous bacterial peritonitis have made use of ceftriaxone in this setting more desirable than quinolones.

Of note, a 2006 study involving patients with advanced cirrhosis (Child Pugh B or C) and GI hemorrhage receiving either norfloxacin or ceftriaxone for 7 days found a significantly lower risk of suspected or proven infections (11% vs 33%) and bacteremia or spontaneous bacterial peritonitis (2% vs 12%) in the ceftriaxone group; there was no difference in hospital mortality. 3 Although the overall prevalence of quinolone-resistant gram-negatives was unknown, 6 of 7 gram-negative bacilli isolated in the norfloxacin group were quinolone resistant.

Bonus Pearl: Did you know that 30-40% of cirrhotic patients presenting with UGIB will develop a bacterial infection within a week of their admission? 1

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References

  1. Chavez-Tapia NC, Barrientos-Gutierrez T, Tellez-Avila F, et al. Meta-analysis: antibiotic prophylaxis for cirrhotic patients with upper gastrointestinal bleeding-an updated Cochrane review. Aliment Pharmacol Ther 2011;34:509-518. https://onlinelibrary.wiley.com/doi/epdf/10.1111/j.1365-2036.2011.04746.x
  2. Mallet M, Rudler M, Thabut D. Variceal bleeding in cirrhotic patients. Gastroenterology Reports 2017;5:185-192. https://academic.oup.com/gastro/article/5/3/185/4002779
  3. Fernandez J, del Arbo LR, Gomez C, et al. Norfloxacin vs ceftriaxone in the prophylaxis of infections in patients with advanced cirrhosis and hemorrhage. Gastroenterology 2006;131:1049-1056. https://www.sciencedirect.com/science/article/abs/pii/S0016508506015356

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Why are antibiotics routinely administered in patients with cirrhosis and upper gastrointestinal (GI) bleed?

Why might hydroxychloroquine and azithromycin be effective against the novel Coronavirus SARS-CoV-2/Covid-19?

FA Manian MD, MPH, , , , , , , , , , , , , Leave a comment

Repurposing of older drugs such as chloroquine or hydroxychloroquine (HC) and more recently, azithromycin (AZ), has received much attention recently in the treatment of Covid-19. Both HC and AZ have immune modulating and antiviral activity that may potentially be effective in our fight against Covid-19.

 
Chloroquine/HC: Chloroquine is an old drug used for its antimalarial activity as well as for its immune modulation and anti-inflammatory properties. It is active in mice against a variety of viruses, including some enteroviruses, Zika virus, and influenza A H5N1 (1). Both chloroquine and HC are active in vitro against Covid-19, though HC appears to be more active (2).

 
Azithromycin: A macrolide often used for treatment of bacterial respiratory tract infections but also with anti-inflammatory and antiviral activity. Azithromycin has been shown to augment interferon response in rhinovirus-infected bronchial epithelial cells as well as in an experimental mouse model of asthma exacerbation (3,4). It also has activity against Zika virus (5). As recently as 2016, some authors opined that macrolides may be useful in pandemic influenza characterized by excessive inflammatory cytokine production because of their anti-inflammatory and interferon-boosting potential (6).

 
March 2020 French clinical trial: A small non-randomized clinical trial involving 36 confirmed Covid-19 patients (mean age 45 y) reported that HC (200 mg 3x/day x 10 days) was associated with rapid viral clearance from nasopharynx, often within 3-6 days (7). The effect was even more pronounced when AZ (500 mg 1st day, followed by 250 mg daily x 4 days) was added in 6 patients.

It’s worth emphasizing that most subjects in this study were either asymptomatic (17%) or had mild disease with upper respiratory tract infection symptoms only (61%). Pneumonia was diagnosed in only 6 patients.  A significant number of patients in the treatment arm also dropped out of the study, some due to ICU transfer.

 
Although such preliminary reports appear promising, the proof of the efficacy and safety of HC and/or AZ in the treatment of Covid-19 awaits larger properly designed clinical studies. Stay tuned!

 

 

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References
1. Touret F, de Lamballerie X. Of chloroquine and COVID-19. Antiviral Research 2020;177. 104762. https://www.ncbi.nlm.nih.gov/pubmed/32147496
2. Yao X, Ye F, Zhang M, et al. In vitro antiviral activity and projection of optimized dosing design of hydroxychloroquine for the treatment of severe acute respirartory syndrome coronavirus 2 (SARS-CoV-2). Clin Infect Dis 2020, March 9. https://www.ncbi.nlm.nih.gov/pubmed/32150618
3. Menzel M, Akbarshai H, Bjermer L, et al. Azithromycin induces anti-viral effects in cultured bronchial epithelial cells from COPD patients. Scientific Reports 2016;6:28698. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4923851/
4. Menzel M, Akbarshai H, Uller L. Azithromycin exhibits interferon-inducing properties in an experimental mouse model of asthma exacerbation. Eur Resp J 2015;46:PA5095. https://erj.ersjournas.com/content/46/suppl_59/PA5095
5. Retallack H, Di Lullo E, Knopp AC, et al. Zika virus cell tropism in the developing human brain and inhibition by azithromycin. Proc Nat Acad Sci USA 2016;113:14408-13. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5167169/
6. Porter JD, Watson J, Roberts LR, et al. Identification of novel macrolides with antibacterial, anti-inflammatory and type I and III-IFN-augmenting activity in airway epithelium. J Antimicrob Chemother 2016;71:2767-81. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031920/
7. Gautret P, Lagier JC, Parola P, et al. Hydroxychloroquine and azithromycin as a treatment of COVID-19:results of an open-label non-randomized clinical trial. International Journal of Antimicrobial Agents—In Press 17 March 2020-DOI: 10.1016/j.ijantimicag.2020.105949 . https://www.sciencedirect.com/science/article/pii/S0924857920300996

 

Disclosures: The listed questions and answers are solely the responsibility of the author and do not necessarily represent the official views of Massachusetts General Hospital, Harvard Catalyst, Harvard University, its affiliate academic healthcare centers, or its contributors. Although every effort has been made to provide accurate information, the author is far from being perfect. The reader is urged to verify the content of the material with other sources as deemed appropriate and exercise clinical judgment in the interpretation and application of the information provided herein. No responsibility for an adverse outcome or guarantees for a favorable clinical result is assumed by the author. Thank you!

Why might hydroxychloroquine and azithromycin be effective against the novel Coronavirus SARS-CoV-2/Covid-19?

Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , , , , , , , 1 Comment

First, a shout-out to dedicated healthcare workers everywhere who have selflessly given of themselves to care for the sick during this pandemic. Thank you! Together, I know we will get through it!

Although our understanding of Covid-19 infection is far from complete, in the spirit of clarity and brevity of my posts on Pearls4Peers, here are some key points I have gleaned from review of existing literature and the CDC that may be useful as we care for our hospitalized patients with suspected or confirmed Covid-19 infection.

  • Isolation precautions.1 Per CDC, follow a combination of airborne (particularly when aerosol generating procedures is anticipated, including nebulizer treatment) and contact precaution protocols. Routinely use masks or respirators, such as N-95s (subject to local availability and policy) and eye protection. Don gowns (subject to local availability and policy) and gloves and adhere to strict hand hygiene practices.

 

  • Diagnostic tests1-9
    • Laboratory tests. Routine admission labs include CBC, electrolytes, coagulation panels and liver and renal tests. Other frequently reported labs include LDH, C-reactive protein (CRP) and procalcitonin. Testing for high sensitivity troponin I has also been performed in some patients, presumably due to concern over ischemic cardiac injury or myocarditis.2 Check other labs as clinically indicated.
    • Chest radiograph/CT chest. One or both have been obtained in virtually all reported cases with CT having higher sensitivity for detection of lung abnormalities.
    • EKG. Frequency of checking EKGs not reported in many published reports thought 1 study reported “acute cardiac injury” in some patients, based in part on EKG findings.4 Suspect we will be checking EKGs in many patients, particularly those who are older or are at risk of heart disease.
    • Point-of-care ultrasound (POCUS). This relatively new technology appears promising in Covid-19 infections, including in rapid assessment of the severity of pneumonia or ARDS at presentation and tracking the evolution of the disease. 9 Don’t forget to disinfect the probe between uses!

 

  • Treatment 1-8
    • Specific therapies are not currently available for treatment of Covid-19 infections, but studies are underway.
    • Supportive care includes IV fluids, 02 supplementation and nutrition, as needed. Plenty of emotional support for patients and their families will likely be needed during these times.
    • Antibiotics have been used in the majority of reported cases, either on admission or during hospitalization when superimposed bacterial pneumonia or sepsis could not be excluded.
      • Prescribe antibiotics against common community-acquired pneumonia (CAP) pathogens, including those associated with post-viral/influenza pneumonia such as Streptococcus pneumoniae (eg, ceftriaxone), and Staphylococcus aureus (eg, vancomycin or linezolid if MRSA is suspected) when concurrent CAP is suspected.
      • Prescribe antibiotics against common hospital-acquired pneumonia (HAP) (eg, vancomycin plus cefepime) when HAP is suspected.
    • Corticosteroids should be avoided because of the potential for prolonging viral replication, unless indicated for other reasons such as COPD exacerbation or septic shock. 1
    • Monitor for deterioration in clinical status even when your hospitalized patient has relatively minor symptoms. This is because progression to lower respiratory tract disease due to Covid-19 often develops during the 2nd week of illness (average 9 days).
    • ICU transfer may be necessary in up to 30% of hospitalized patients due to complications such as ARDS, secondary infections, and multi-organ failure.

 

Again, thank you for caring for the sick and be safe! Feel free to leave comments or questions.

 

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References

  1. CDC. Interim clinical guidance for management of patients with confirmed coronavirus disease (COVID-19). https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html
  2. Ruan Q, Yang K, Wang W, Jiang L, et al. Clinical predictors of mortality due to COVID-19 based on analysis of data of 150 patients with Wuhan, China. Intensive Care Med 2020. https://link.springer.com/article/10.1007/s00134-020-05991-x
  3. Holshue ML, BeBohlt C, Lindquist S, et al. First case of 2019 novel coronavirus in the United States. N Engl J Med 2020;382:929-36. https://www.nejm.org/doi/full/10.1056/NEJMoa2001191
  4. Huang C, Wang Y, Li Xingwang, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020;395:497-506. https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(20)30183-5.pdf
  5. Young BE, Ong SWX, Kalimuddin S, et al. Epideomiologic features and clinical course of patients infected with SARS-CoV-2 Singapore. JAMA, March 3, 2020. Doi.10.1001/jama.2020.3204 https://www.ncbi.nlm.nih.gov/pubmed/32125362
  6. Chen N, Zhou M, Dong X, et al. Epidemiological and clinical chacteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study. Lancet 2020;395:507-13. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30211-7/fulltext
  7. Guan W, Ni Z, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl Med 2020, Feb 28, 2020. https://www.nejm.org/doi/full/10.1056/NEJMoa2002032
  8. Zhang J, Zhou L, Yang Y, et al. Therapeutic and triage strategies for 2019 novel coronavirus disease in fever clinics. Lancet 2020;8: e11-e12. https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30071-0/fulltext 9.
  9. Peng QY, Wang XT, Zhang LN, et al. Findings of lung ultrasonography of novel corona virus pneumonia during the 2019-2020 epidemic. Intensive Care Med 2020. https://doi.org/10.1007/s00134-020-05996-
Key clinical pearls in the medical management of hospitalized patients with coronavirus (Covid-19) infection

When should I consider a switch to oral antibiotics and discharge from hospital in my recently admitted elderly patient with community-acquired pneumonia (CAP)?

FA Manian MD, MPH, , , , , , , , , , , , , , , , , , , , , Leave a comment

A frequently used validated set of clinical stability criteria in patients with CAP and supported by the 2019 ATS/IDSA CAP guidelines consists of a temperature ≤37.8 ᵒC (100.0 ᵒF) AND no more than 1 CAP-related sign of clinical instability as listed below: 1-3

  • Heart rate >100/min
  • Systolic blood pressure <90 mm Hg
  • Respiration rate >24 breaths/min
  • Arterial oxygen saturation <90% or Pa02<60 mm Hg (room air)

Using these criteria, the risk of clinical deterioration serious enough to necessitate transfer to an intensive care unit may be 1% or less, 1 while failure to achieve clinical stability within 5 days is associated with higher mortality and worse clinical outcome. 2 The median time to clinical stability (as defined) for CAP treatment is 3 days.1  

A 2016 randomized-controlled trial involving patients hospitalized with CAP found that implementation of above clinical stability criteria was associated with safe discontinuation of antibiotics after a minimum of 5 days of appropriate therapy. 3 

Potential limitations of the above study include heavy use of quinolones (80%), underrepresentation of patients with severe CAP (Pneumonia Risk Index, PSI, V), and exclusion of nursing home residents, immunosuppressed patients, those with chest tube, or infection caused by less common organisms, such as Staphylococcus aureus or Pseudomonas aeruginosa.

Lack of clinical stability after 5 days of CAP treatment should prompt evaluation for complications of pneumonia (eg, empyema, lung abscess), infection due to  organisms resistant to selected antibiotics, or an alternative source of infection/inflammatory/poor response. 2

References

  1. Halm, EA, Fine MJ, Marrie TJ, et al. Time to clinical stability in patients hospitalized with community-acquired pneumonia: implications for practice guidelines. JAMA 1998;279:279:1452-57. https://reference.medscape.com/medline/abstract/9600479
  2. Metlay JP, Waterer GW, Long AC, et al. Diagnosis and treatment of adults with community-acquired pneumonia. Am J Respir Crit Care Med 2019;200:e45-e67. https://www.ncbi.nlm.nih.gov/pubmed/31573350
  3. Uranga A, Espana PP, Bilbao A, et al. Duration of antibiotic treatment in community-acquired pneumonia. A multicenter randomized clinical trial. JAMA Intern Med 2016;176:1257-65. https://www.ncbi.nlm.nih.gov/pubmed/27455166/
When should I consider a switch to oral antibiotics and discharge from hospital in my recently admitted elderly patient with community-acquired pneumonia (CAP)?

My patient with diverticular bleed has now developed signs of bowel ischemia with abdominal pain and sepsis after transcatheter colic artery embolization. Is bowel ischemia common after embolization of lower gastrointestinal (GI) arteries?

FA Manian MD, MPH, , , , , , , , Leave a comment

It may be more common than we think! Reported rates of bowel ischemia following lower GI artery embolization have been as high as 22% (1,2). For this reason, it is prudent to closely monitor for signs of bowel ischemia and infection in patients who undergo embolization to control lower GI bleeding.

In some cases, ischemia of the bowel appears to be mild enough to be treated conservatively, while in other cases bowel infarction with surgical intervention has been necessary (1).  One case report described signs of infection (including fever, abdominal tenderness and leukocytosis) 2 days after arterial embolization in a patient who was treated conservatively (3), while another described “sepsis” 6 days post procedure with bowel wall ischemia requiring surgical resection (1). 

Bowel injury leading to a septic picture following embolization of lower GI arteries should not be surprising given the expected capillary hypoperfusion and risk of tissue hypoxia.  Compared to embolization for upper GI bleed, lower GI embolization may place the patient at higher risk of bowel ischemia bowel ischemia due to lack of a rich collateral blood supply (1).  Older patients may also have mesenteric artery atherosclerotic disease or low cardiac output,  further compromising the collateral blood flow (3).  

At a more molecular level, hypoxia leads to the activation of hypoxia-inducible factor (HIF-1), which plays an important role in inducing gut injury. In fact, deletion of HIF-1a in mice prevented shock-induced intestinal permeability and bacterial translocation that ultimately led to bacteremia (4). 

As for preventing embolization-induced bacteremia, although antibiotics are used for liver and spleen embolization prophylaxis, their role in colic angioembolization is unclear (5).  

Bonus Pearl: Did you know that some of the earliest angioembolizations were performed during the Vietnam War to stop bleeding from bullet injuries? (6)

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References:

  1. Gady, J, Reynolds, H., & Blum, A. Selective arterial embolization for control of lower gastrointestinal bleeding: Recommendations for a clinical management pathway. Current Surg 2003; 60: 344-347. https://www.sciencedirect.com/science/article/abs/pii/S0149794402007493
  2. Rossetti A, Buchs NC, Breguet R, et al. Transarterial embolization in acute colonic bleeding: review of 11 years of experience and long-term results. Int J Colo Dis 2013;28:777-782. https://link.springer.com/article/10.1007/s00384-012-1621-5
  3. Shenoy, S, Satchidanand, S, & Wesp S. Colonic ischemic necrosis following therapeutic embolization. Gastrointest Radiol 1981, 6: 235-237. https://link.springer.com/article/10.1007/BF01890256
  4. Vollmar, B., & Menger, M. Intestinal ischemia/reperfusion: Microcirculatory pathology and functional consequences. Langenbeck Arch Surg 2011; 396: 13-29 https://link.springer.com/article/10.1007%2Fs00423-010-0727-x 
  5. Ryan, J. Mark, Ryan, Barbara M, & Smith, Tony P. Antibiotic prophylaxis in interventional radiology. JVIR 2004; 15: 547-556. https://www.sciencedirect.com/science/article/pii/S1051044307603248
  6. Nolan, T, Phan H, Hardy A, et al. Bullet embolization: Multidisciplinary approach by interventional radiology and surgery. Semin Interven Radiol 2012, 29: 192-6. https://www.ncbi.nlm.nih.gov/pubmed/23997411 

Contributed by Hannah Ananda Bougleux Gomes, Medical Student, Harvard Medical School, Boston, MA.

My patient with diverticular bleed has now developed signs of bowel ischemia with abdominal pain and sepsis after transcatheter colic artery embolization. Is bowel ischemia common after embolization of lower gastrointestinal (GI) arteries?

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

FA Manian MD, MPH, , , , , , , , , , , , , , , Leave a comment

Although traditionally 7 to 14 days of antibiotic therapy has been recommended for Gram-negative bacteremia, more recent studies suggest that shorter antibiotic treatment courses are as effective as longer treatments for a variety of infections, particuarly those due to Enterobacteriaceae (eg, E. Coli, Klebsiella sp) in patients with low severity illness (1). 

Keep in mind that short course therapy may not apply to all patients with UTI and bacteremia, such as those with prostatitis (not included in the most recent study [1,2]), which requires longer course of antibiotics (3)

 
A 2019 randomized-controlled study involving primarily patients with bacteremia caused by E. Coli or Klebsiella sp. (~75%) with most cases associated with UTI (~70%) found that 7 days was as effective as 14 days of treatment in hemodynamically stable patients who are afebrile for at least 48 hours without an ongoing focus of infection (1). More specifically, there was no significant difference between the 2 groups in the rates of relapse of bacteremia or mortality at 14 or 28 days.

 
An accompanying editorial concluded that “7 days of treatment may be sufficient for hospitalized, non-critically ill patients with Gram-negative bacteremia and with signs of early response to treatment” (4)  Again, the accent should be on hemodynamically stable patients who respond rapidly to treatment. 

 
Bonus Pearl: While on the subject of shorter course antibiotic therapy, a 2016 “mantra” article nicely summarizes more recent suggestions for common infectious disease conditions (5). Obviously, clinical judgment should be exercised in all cases.
• Community-acquired pneumonia                               3-5 days (vs 7-10 days)
• Nosocomial pneumonia                                                 8 days or less (vs 10-15 days)
• Pyelonephritis                                                                  5-7 days (vs 10-14 days)
• Intraabdominal infection                                             4 days (vs 10 days)
• COPD acute exacerbation                                             5 days or less (vs >6 days)
• Acute bacterial sinusitis                                               5 days (vs 10 days)
• Cellulitis                                                                            5-6 days (vs 10 days)

 

 

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References
1. Yahav D, Franceschini E, Koppel F, et al. Seven versus 14 days of antibiotic therapy for uncomplicated Gram-negative bacteremia: A noninferiority randomized controlled trial. Clin Infect Dis 2019; 69:1091-8. https://academic.oup.com/cid/article/69/7/1091/5237874       2. Yahav D, Mussini C, Leibovici L, et al. Reply to “Should we treat bacteremic prostatitis for 7 days”.  Clin Infect Dis 2010;70:751-3. DOI:10:1093/cid/ciz393.

3.  De Greef J, Doyen L, Hnrard S, et al. Should we treat bacteremic prostatitis for 7 days? Clin Infect Dis 2020;70:351https://academic.oup.com/cid/article-abstract/70/2/351/5488067?redirectedFrom=fulltext
4. Daneman D, Fowler RA. Shortening antibiotic treatment durations for bacteremia. Clin Infect Dis 2019;69:1099-1100. https://academic.oup.com/cid/article-abstract/69/7/1099/5237877?redirectedFrom=fulltext
5. Spellberg B. The new antibiotic mantra: “ Shorter is better”. JAMA Intern Med 2016;176:1254-55. https://jamanetwork.com/journals/jamainternalmedicine/article-abstract/2536180

How long should I treat my patient with urinary tract infection and E. Coli bacteremia?

My patient has developed isolated eosinophilia without symptoms while receiving an antibiotic. Should I consider discontinuing the antibiotic or can I just continue it as long as she has no symptoms?

FA Manian MD, MPH, , , , , , , Leave a comment

Short answer: We don’t really know what’s the best way to manage patients with  isolated (asymptomatic) eosinophilia (IE) that develops during antibiotic therapy. We do know that the majority of patients with IE may never develop hypersensitivity reaction such as rash, renal or liver injuries, but predicting who will or will not get HSRs is a challenge.1-3 Couple of studies may help us in our decision making, however.

In a 2015 study1 involving patients receiving outpatient parenteral antibiotics, eosinophilia was present in 25% of patients during their course of treatment, of whom 30% subsequently developed HSR and 5% developed more than 1 sign of HSR. Patients with IE and subsequent HSR developed eosinophilia earlier in their course of treatment (median 11 vs 17 days) and had a higher peak absolute eosinophil count (~ 850 vs ~700/ ml).  The authors suggested that close monitoring for rash and renal injury in patient with IE during antibiotic therapy be considered, and that medication changes may be necessary when IE is associated with earlier onset of eosinophilia or higher absolute eosinophil count.

In a 2017 prospective study2 of patients with eosinophilic drug reactions (~20% related to antibiotics), the majority (56%) were asymptomatic. Earlier onset of eosinophilia and higher eosinophil count were associated with symptomatic eosinophilia, similar to the aforementioned study. The frequency of patients with IE who went on to have symptomatic eosinophilia when the suspect drug was continued vs those in whom it was not continued remains unclear from these studies.

Ultimately, the decision to continue or discontinue a suspect antibiotic when your patient has new-onset IE should be made on a case-by-case basis, taking into account the severity of the patient’s infection, availability of equally effective and tolerated alternative drugs and the ability to closely monitor for symptomatic disease. The timing of onset of eosinophilia and its peak absolute count may also play a role.

Bonus pearl: Did you know that only 18% of inpatients with cutaneous drug eruptions may have peripheral eosinophilia?4

The author acknowledges the invaluable input of Kimberly Blumenthal, MD in composing this pearl.

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References

  1. Blumenthal KG, Youngster I, Rabideau DJ, et al. Peripheral blood eosinophilia and hypersensitivity reactions among patients receiving outpatient parenteral antibiotics. J Allergy Clin Immunol 2015;136:1288.1294. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4640981/
  2. Ramirez E, Mdrano-Casique N, Tong HY, et al. Eosinophilic drug reactions detected by a prospective pharmacovigilance programme in a tertiary hospital. Br J Pharmacol 2017;83:400-15. https://bpspubs.onlinelibrary.wiley.com/doi/pdf/10.1111/bcp.13096
  3. Rauscher C, Freeman A. Drug-induced eosinophilia. Allergy Asthma Proc 2018;39:252-56. https://www.ncbi.nlm.nih.gov/pubmed/29669671
  4. Romagosa R, Kapoor S, Sanders J, et al. inpatient adverse cutaneous drug erutpions and eosinophilia. Arch Dermatol 2001; 137:511-12. https://www.ncbi.nlm.nih.gov/pubmed/11295947   

 

 

My patient has developed isolated eosinophilia without symptoms while receiving an antibiotic. Should I consider discontinuing the antibiotic or can I just continue it as long as she has no symptoms?

Should I routinely treat my patients with acute COPD exacerbation with antibiotics?

FA Manian MD, MPH, , , , , , Leave a comment

The answer is “NO”! With an estimated 20% to 50% of acute chronic obstructive pulmonary disease (COPD) exacerbations attributed to noninfectious factors (1,2), routine inclusion of antibiotics in the treatment of this condition is not only unnecessary but potentially harmful.

 
Although the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines recommends the use of antibiotics in patients who have dyspnea, increased sputum volume, and increased sputum purulence—or at least 2 of these 3 criteria when sputum purulence is one of them (3)—, these recommendations are not based on robust evidence and have not been widely corroborated (2,4-6).

 
That’s why the findings of a 2019 New England Journal of Medicine study (PACE) supporting the use of serum C-reactive protein (CRP) as an adjunctive test in COPD exacerbation is particularly welcome (1). In this multicenter randomized controlled trial performed in the U.K., the following CRP guidelines (arrived from prior studies) were provided to primary care clinicians to be used as part of their decision making in determining which patients with COPD exacerbation may not need antibiotic therapy:
• CRP less than 20 mg/L: Antibiotics unlikely to be beneficial
• CRP 20-40 mg/L: Antibiotics may be beneficial, mainly if purulent sputum is present
• CRP greater than 40 mg/L: Antibiotics likely to be beneficial

 
Adoption of these guidelines resulted in significantlly fewer patients being placed on antibiotics without evidence of harm over a 4-week follow-up period (1).  Despite its inherent limitations (eg, single country, outpatient setting), CRP testing may be a step in the right direction in curbing unnecessary use of antibiotics in COPD exacerbation.  

 

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References
1. Butler CC, Gillespie D, White P, et al. C-reactive protein testing to guide antibiotic prescribing for COPD exacerbations. N Engl J Med 2019;381:111-20. https://www.ncbi.nlm.nih.gov/pubmed/31291514
2. Llor C, Moragas A, Hernandez S, et al. Efficacy of antibiotic therapy for acute exacerbations of mild to moderate chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2012;186:716-23. https://www.ncbi.nlm.nih.gov/pubmed/22923662
3. Global Initiative for Chronic Obstructive Lung Disease. Global strategy for the diagnosis, management, and prevention of chronic obstructive pulmonary disease. GOLD, 2019 (http://www.goldcopd.org).
4. Brett AS, Al-Hasan MN. COPD exacerbations—A target for antibiotic stewardship. N Engl J Med 2018;381:174-75. https://www.ncbi.nlm.nih.gov/pubmed/31291521
5. Miravitlles M, Moragas A, Hernandez S, et al. Is it possible to identify exacerbations of mild to moderate COPD that do not require antibiotic treatment? Chest 2013;144:1571-7. https://www.ncbi.nlm.nih.gov/pubmed/23807094
6. Van Vezen P, Ter Riet G, Bresser P, et al. Doxycycline for outpatient-treated acute exacerbations of COPD: a randomized double-blind placebo-controlled trial. Lancet Respir Med 2017;5:492-9. https://www.ncbi.nlm.nih.gov/pubmed/28483402

Should I routinely treat my patients with acute COPD exacerbation with antibiotics?

Is meropenem a good choice of antibiotic for treatment of my patient’s intraabdominal infection involving enterococci?

FA Manian MD, MPH, , , , , , , , , Leave a comment

Although meropenem is a broad spectrum antibiotic that covers many gram-negative and gram-positive organisms as well as anaerobes, its activity against enterococci is generally poor and leaves much to be desired.

In a study of ampicillin-sensitive E. faecalis isolates from hospitalized patients, only 36% of isolates were considered susceptible (MIC≤4 mg/L); activity against E. faecium isolates was similarly poor.1 Several other studies have reported the suboptimal activity of meropenem against both E. faecalis and E. faecium, 2-4 with susceptibility rates as low as 8.6% depending on the MIC break point used.3

A popular textbook and a handbook on infectious diseases also do not recommend the use of meropenem for treatment of enterococcal infections. 5,6

Of interest, the package insert states that meropenem is indicated for complicated skin and soft tissue infections due to a variety of organisms, including E. faecalis (vancomycin-susceptible isolates only), but not for complicated intra-abdominal infections or meningitis due this organism.7

In our patient with intraabdominal infection,  we may consider piperacillin-tazobactam instead.  Piperacillin-tazobactam is a broad spectrum antibiotic with excellent coverage against anaerobes and ampicillin-susceptible E. faecalis.1,8  

 

References

  1. Endtz HP, van Dijk WC, Verbrugh HA, et al. Comparative in-vitro activity of meropenem against selected pathogens from hospitalized patients in the Netherlands. J Antimicrob Chemother 1997;39:149-56. https://www.ncbi.nlm.nih.gov/pubmed/9069534
  2. Pfaller MA, Jones RN. A review of the in vitro activity of meropenem and comparative antimicrobial agents tested against 30,254 aerobic and anaerobic pathogens isolated world wide. Diag Microbiol Infect Dis 1997;28:157-63. https://www.ncbi.nlm.nih.gov/pubmed/9327242
  3. Hallgren A, Abednazari H, Ekdahl C, et al. Antimicrobial susceptibility patterns of enterococci in intensive care units in Sweden evaluated by different MIC breakpoint systems. J Antimicrob Chemother 2001;48:53-62. https://www.ncbi.nlm.nih.gov/pubmed/11418512
  4. Hoban DJ, Jones RN, Yamane N, et al. In vitro activity of three carbapenem antibiotics comparative studies with biapenem (L-627), imipenem, and meropenem against aerobic pathogens isolated worldwide. Diag Microbiol Infect Dis 993;17:299-305.https://www.ncbi.nlm.nih.gov/pubmed/8112045
  5. Chambers HF. Carbapenem and monobactams. In Mandell GL et al. eds. Principles and practice of infectious diseases. 2010, pp 341-45.
  6. Cunha CB, Cunha BA. Antibiotic essentials. 2017, pp 689-91.
  7. Meropenem.http://online.lexi.com/lco/action/doc/retrieve/docid/patch_f/7253?searchUrl=%2Flco%2Faction%2Fsearch%3Fq%3Dmeropenem%26t%3Dname
  8. Perry CM, Markham A. Piperacillin/tazobactam. Drugs 1999;57:805-43. https://link.springer.com/article/10.2165%2F00003495-199957050-00017

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Is meropenem a good choice of antibiotic for treatment of my patient’s intraabdominal infection involving enterococci?