Acute Mesenteric Ischemia Medication

Drug types employed in the treatment of acute mesenteric ischemia (AMI) include vasodilators, thrombolytics, anticoagulants, antibiotics, and analgesics. Withhold therapeutic drugs (except analgesics and prophylactic antibiotics) until the type of AMI present has been determined by means of computed tomography (CT) scanning or angiography.

Class Summary

Vasodilators dilate the mesenteric arterial system. They thereby reverse reactive arterial vasospasms in AMI.

Papaverine

Papaverine is a benzylisoquinoline derivative that exerts a direct nonspecific relaxant effect on vascular, cardiac, and other smooth muscle. In the absence of peritoneal signs, it is the drug of choice for AMI of arterial origin if angiography indicates good distal perfusion. Papaverine is advocated for treatment of the widespread vasoconstriction that follows therapy for superior mesenteric artery (SMA) emboli by other modalities.

Class Summary

Thrombolytics are angiographically infused to lyse thrombi. They are used in selected patients with embolic AMI.

Alteplase, tissue plasminogen activator (Activase)

Alteplase is a synthetic tissue plasminogen activator (tPA) used to manage acute myocardial infarction, ischemic stroke, and pulmonary embolism. Its use in AMI is controversial and potentially dangerous. Alteplase may be indicated in patients with embolic AMI if no signs of peritonitis are present. The safety and efficacy of concomitant administration with aspirin and heparin during the first 24 hours after onset of symptoms have not been investigated.

Reteplase (Retavase)

Reteplase is a recombinant tPA that forms plasmin after facilitating cleavage of endogenous plasminogen. In clinical trials with acute myocardial infarction, reteplase has been shown to be comparable to tPA in achieving TIMI (thrombolysis in myocardial infarction risk score) 2 or 3 patency 2 or 3 patency at 90 minutes. Heparin and aspirin usually are given concomitantly and after.

Tenecteplase (TNKase)

Tenecteplase is a modified version of alteplase (t-PA) made by substituting 3 amino acids of alteplase. It can be given as a single bolus over a 5-second infusion, instead of over 90 minutes with alteplase. Tenecteplase appears to cause less nonintracranial bleeding, but it has a similar risk of intracranial bleeding and stroke as alteplase. Base the dose on the patient's weight. Because tenecteplase contains no antibacterial preservatives, reconstitute it immediately before use.

Class Summary

Anticoagulants are indicated to prevent further extension of thrombus in mesenteric venous thrombosis (MVT) or postrevascularization in arterial occlusive AMI. In arterial occlusive AMI, whether anticoagulant therapy should be started immediately or after 48 hours when infarction is clearly absent is undetermined, because of the risk of gastrointestinal (GI) bleeding. Oral anticoagulants are used for maintenance therapy. They interfere with hepatic synthesis of vitamin K–dependent coagulation factors.

Heparin

Heparin augments the activity of antithrombin III and prevents conversion of fibrinogen to fibrin. This drug does not actively lyse but is able to inhibit further thrombogenesis. It prevents reaccumulation of clot after spontaneous fibrinolysis.

Warfarin (Coumadin, Jantoven)

Convert patients with MVT from heparin to warfarin when possible. Continue for 6 months if no contraindication or identifiable hypercoagulable state exists. Maintain patients on warfarin for life if a permanent hypercoagulable state exists. Warfarin is also indicated to prevent further embolization in patients with atrial fibrillation. It is used for prophylaxis and treatment of venous thrombosis, pulmonary embolism, and thromboembolic disorders. Tailor the dose to maintain the international normalized ratio (INR) in the 2-3 range.

Class Summary

Antibiotics are administered to prevent or treat sepsis caused by breakdown of the mucosal barrier in bowel necrosis or perforation.

Clindamycin (Cleocin)

Clindamycin is a lincosamide used for treatment of serious skin and soft tissue staphylococcal infections. It is also effective against aerobic and anaerobic streptococci (except enterococci). It inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest.

Metronidazole (Flagyl)

Metronidazole is an imidazole ring–based antibiotic active against various anaerobic bacteria and protozoa. It is used in combination with other antimicrobial agents (except for Clostridium difficile enterocolitis).

Ticarcillin and clavulanate (Timentin)

Ticarcillin-clavulanate inhibits biosynthesis of cell wall mucopeptide and is effective during the stage of active growth. It consists of an antipseudomonal penicillin plus a beta-lactamase inhibitor and provides coverage against most gram-positive organisms, most gram-negative organisms, and most anaerobes.

Cefotetan (Cefotan)

Cefotetan is a second-generation cephalosporin indicated for infections caused by susceptible gram-positive cocci and gram-negative rods. The dose and route of administration depend on the condition of the patient, the severity of the infection, and the susceptibility of the causative organism.

Cefoxitin (Mefoxin)

Cefoxitin is a second-generation cephalosporin that is indicated for infections with gram-positive cocci and gram-negative rods. Infections caused by cephalosporin- or penicillin-resistant gram-negative bacteria may respond to cefoxitin.

Meropenem (Merrem)

Meropenem is a bactericidal broad-spectrum carbapenem antibiotic that inhibits cell wall synthesis. It is effective against most gram-positive and gram-negative bacteria.

Class Summary

For relief of pain caused by bowel ischemia.

Morphine (Duramorph)

Morphine is the drug of choice for analgesia because of its reliable and predictable effects, its safety profile, and ease with which its effects can be reversed by giving naloxone. Various IV doses are used; these are commonly titrated until the desired effect is obtained.