Medication Summary
Antibiotics initially are chosen empirically and should be based on the location of the infected thrombus as detailed above. Broad coverage is generally warranted until blood cultures taken from the suppurative vessel have results, at which point deescalation of microbial coverage is appropriate. Because many infections are caused by S aureus, coverage of MRSA should routinely be administered in most cases on initial patient presentation.
Anticoagulation can be considered based on the location of the infected thrombus, and localized fibrinolysis may be warranted in the case of central catheter–associated disease.
Antibiotics
Class Summary
Antibiotics are initially chosen empirically and should be based on the location of the infected thrombus as detailed above. Broad coverage is generally warranted until blood cultures taken from the suppurative vessel have results, at which point deescalation of microbial coverage is appropriate. Because many infections are caused by S aureus, coverage of MRSA should routinely be administered in most cases on initial patient presentation.
Vancomycin
Vancomycin is an antibiotic directed against gram-positive organisms and active against Enterococcus species as well as community-acquired and hospital-acquired MRSA.
Ceftriaxone (Rocephin)
Ceftriaxone is a third-generation cephalosporin with broad-spectrum, gram-negative activity. It has less gram-positive coverage than earlier-generation cephalosporins. It is bactericidal and inhibits cell wall synthesis by binding to penicillin-binding proteins.
Cefepime (Maxipime)
Cefepime is a fourth-generation cephalosporin with coverage similar to ceftriaxone, with the added benefit of pseudomonal coverage.
Clindamycin (Cleocin)
Clindamycin is a lincosamide used for the treatment of serious skin and soft-tissue staphylococcal infections. It is also effective against aerobic and anaerobic streptococci (except enterococci). Clindamycin inhibits bacterial growth, possibly by blocking dissociation of peptidyl transfer ribonucleic acid (tRNA) from ribosomes, causing RNA-dependent protein synthesis to arrest.
Ampicillin-sulbactam (Unasyn)
Ampicillin-sulbactam is ampicillin plus a beta-lactamase inhibitor. It interferes with cell wall synthesis during active replication, causing bactericidal activity. It covers skin, enteric flora, and anaerobes.
Piperacillin and tazobactam sodium (Zosyn)
This is an antipseudomonal penicillin plus a beta-lactamase inhibitor. It inhibits the biosynthesis of cell wall mucopeptide and is effective during the stage of active multiplication.
Imipenem-cilastatin (Primaxin)
Imipenem is a carbapenem. It inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins. Cilastatin prevents renal metabolism. It has excellent gram-negative (including pseudomonal) and anaerobic coverage.
Metronidazole (Flagyl)
Metronidazole is an imidazole ring-based antibiotic that is particularly active against various anaerobic bacteria and protozoa.
Fluconazole (Diflucan)
Fluconazole is a selective inhibitor of fungal cytochrome P-450 dependent enzyme. It has fungistatic activity against many candidal species.
Amphotericin B liposomal (AmBisome)
Amphotericin B, which is produced by a strain of Streptomyces nodosus, can be fungistatic or fungicidal (effective against candidal phlebitis). It binds to sterols, such as ergosterol, in the fungal cell membrane, causing intracellular components to leak, with subsequent fungal cell death.
Fibrinolytics (Thrombolytics)
Class Summary
The goal of fibrinolytic therapy is to dissolve an infected fibrin sheath or an infected thrombus that can serve as a nidus for resistant infection and as a source of septic emboli. Catheter-directed local infusions of fibrinolytic agents are safer than systemic fibrinolytic regimens because they use a low dose of the drug and usually do not produce a systemic lytic state. Several fibrinolytic agents are available for local-regional lysis of infected thrombus.
Reteplase (Retavase)
Reteplase is a second-generation recombinant tissue-type plasminogen activator. As a fibrinolytic agent, it seems to work faster than its forerunner, alteplase, and also may be more effective in patients with larger clot burden. In addition, reteplase has been reported to be more effective than other agents in the lysis of older clots. In patients being treated for peripheral vascular disease, reteplase has been reported to cause fewer bleeding complications than alteplase.
Alteplase (Activase)
Alteplase was the first recombinant tissue plasminogen activator to be released for clinical use; it is the agent with which EDs are most familiar.
Although alteplase is best known as a fibrinolytic agent used for coronary artery occlusion and pulmonary embolism, it is also widely used for catheter-directed lysis of deep venous thrombosis, for dissolution of catheter-related thrombus, and for reopening of occluded central lines and thrombosed dialysis grafts.
Anticoagulants, Cardiovascular
Class Summary
Anticoagulation with some form of heparin is essential in patients with septic phlebitis, but anticoagulation alone does not guarantee a successful outcome. Progression of the disease may occur despite full and effective heparin anticoagulation. Warfarin should not be used in the acute treatment of septic phlebitis, because the early risk of increased thrombogenesis outweighs any convenience of oral therapy.
Heparin
Heparin is an indirect thrombin inhibitor that complexes with antithrombin to slow or prevent the progression of venous thrombosis. Heparin does not dissolve existing clots. When unfractionated heparin is used, an aPTT of at least 1.5-times the control value is necessary for a therapeutic effect.
Enoxaparin (Lovenox)
Enoxaparin was the first LMWH released in United States and is FDA approved for both the treatment and the prophylaxis of deep venous thrombosis. Enoxaparin is widely used in pregnancy, although clinical trials are not yet available to demonstrate that it is as safe as unfractionated heparin. There is no utility in checking the aPTT; enoxaparin has a wide therapeutic window and the aPTT does not correlate with the anticoagulant effect.
