Zosyn, (piperacillin-tazobactam) dosing, indications, interactions, adverse effects, and more (original) (raw)

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Contraindicated (0)

Serious (12)

• antithrombin alfa
  piperacillin increases effects of antithrombin alfa by pharmacodynamic synergism. Avoid or Use Alternate Drug.
• antithrombin III
  piperacillin increases effects of antithrombin III by pharmacodynamic synergism. Avoid or Use Alternate Drug.
• argatroban
  piperacillin will increase the level or effect of argatroban by anticoagulation. Avoid or Use Alternate Drug. cephalosporins may decrease prothrombin activity
• BCG vaccine live
  piperacillin decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until antibiotic treatment complete to administer live bacterial vaccine; antibiotics may diminish therapeutic effects of BCG.
• bivalirudin
  piperacillin will increase the level or effect of bivalirudin by anticoagulation. Avoid or Use Alternate Drug. cephalosporins may decrease prothrombin activity
• cholera vaccine
  piperacillin, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.
• dalteparin
  piperacillin increases effects of dalteparin by anticoagulation. Avoid or Use Alternate Drug. Piperacillin can inhibit platelet aggregation.
• enoxaparin
  piperacillin increases effects of enoxaparin by anticoagulation. Avoid or Use Alternate Drug. Piperacillin can inhibit platelet aggregation.
• heparin
  piperacillin will increase the level or effect of heparin by anticoagulation. Avoid or Use Alternate Drug. piperacillin can inhibit platelet aggregation
• microbiota oral
  piperacillin decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .
• omadacycline
  omadacycline decreases effects of piperacillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.
• sarecycline
  sarecycline decreases effects of piperacillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.

Monitor Closely (34)

• atezolizumab
  piperacillin decreases effects of atezolizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• avelumab
  piperacillin decreases effects of avelumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• azithromycin
  azithromycin decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• balstilimab
  piperacillin decreases effects of balstilimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• bazedoxifene/conjugated estrogens
  piperacillin will decrease the level or effect of bazedoxifene/conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.
• camrelizumab
  piperacillin decreases effects of camrelizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• cemiplimab
  piperacillin decreases effects of cemiplimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• chloramphenicol
  chloramphenicol decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• clarithromycin
  clarithromycin decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• cosibelimab
  piperacillin decreases effects of cosibelimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• demeclocycline
  demeclocycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• dichlorphenamide
  dichlorphenamide and piperacillin both decrease serum potassium. Use Caution/Monitor.
• dostarlimab
  piperacillin decreases effects of dostarlimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• doxycycline
  doxycycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• durvalumab
  piperacillin decreases effects of durvalumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• erythromycin base
  erythromycin base decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• erythromycin ethylsuccinate
  erythromycin ethylsuccinate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• erythromycin lactobionate
  erythromycin lactobionate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• erythromycin stearate
  erythromycin stearate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• minocycline
  minocycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• nivolumab
  piperacillin decreases effects of nivolumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• pembrolizumab
  piperacillin decreases effects of pembrolizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• penpulimab
  piperacillin decreases effects of penpulimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• probenecid
  probenecid will increase the level or effect of piperacillin by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
• retifanlimab
  piperacillin decreases effects of retifanlimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• sintilimab
  piperacillin decreases effects of sintilimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• sodium picosulfate/magnesium oxide/anhydrous citric acid
  piperacillin decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.
• tetracycline
  tetracycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.
• tislelizumab
  piperacillin decreases effects of tislelizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• toripalimab
  piperacillin decreases effects of toripalimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.
• vancomycin
  piperacillin increases toxicity of vancomycin by unspecified interaction mechanism. Use Caution/Monitor. Monitor kidney function in patients concomitantly administered with piperacillin and vancomycin.
• vecuronium
  piperacillin increases toxicity of vecuronium by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Neuromuscular blockade may be prolonged.
• warfarin
  piperacillin, warfarin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Platelet dysfunction occurs with extended-spectrum penicillins in varying degrees. Monitor INR and adjust warfarin dose if needed.
• xanomeline/trospium
  piperacillin, xanomeline/trospium. Either increases levels of the other by decreasing elimination. Use Caution/Monitor. Coadministration of trospium with other drugs eliminated by active tubular secretion may increase plasma concentrations of trospium and/or the concomitantly used drug owing to competition for this elimination pathway. Monitor for increased frequency and/or severity of adverse reactions.

Minor (15)

• amikacin
  piperacillin increases effects of amikacin by pharmacodynamic synergism. Minor/Significance Unknown.

• aspirin
  piperacillin, aspirin. Either increases effects of the other by receptor binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug.

• aspirin rectal
  piperacillin will increase the level or effect of aspirin rectal by plasma protein binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug

• aspirin/citric acid/sodium bicarbonate
  piperacillin will increase the level or effect of aspirin/citric acid/sodium bicarbonate by plasma protein binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug

• chlorothiazide
  chlorothiazide increases levels of piperacillin by decreasing renal clearance. Minor/Significance Unknown.

• choline magnesium trisalicylate
  piperacillin will increase the level or effect of choline magnesium trisalicylate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown. Salicylate saltscould be displaced from binding sites or could displace other highly protein-bound drugs such as penicillins

• gentamicin
  piperacillin increases effects of gentamicin by pharmacodynamic synergism. Minor/Significance Unknown.

• hydrochlorothiazide
  hydrochlorothiazide increases levels of piperacillin by decreasing renal clearance. Minor/Significance Unknown.

• ibuprofen IV
  piperacillin will increase the level or effect of ibuprofen IV by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• meclofenamate
  piperacillin will increase the level or effect of meclofenamate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• neomycin PO
  piperacillin increases effects of neomycin PO by pharmacodynamic synergism. Minor/Significance Unknown.

• rose hips
  rose hips will increase the level or effect of piperacillin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• streptomycin
  piperacillin increases effects of streptomycin by pharmacodynamic synergism. Minor/Significance Unknown.

• tobramycin
  piperacillin increases effects of tobramycin by pharmacodynamic synergism. Minor/Significance Unknown.

• willow bark
  piperacillin will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• amikacin
  Minor (1)piperacillin increases effects of amikacin by pharmacodynamic synergism. Minor/Significance Unknown.

• antithrombin alfa
  Serious - Use Alternative (1)piperacillin increases effects of antithrombin alfa by pharmacodynamic synergism. Avoid or Use Alternate Drug.

• antithrombin III
  Serious - Use Alternative (1)piperacillin increases effects of antithrombin III by pharmacodynamic synergism. Avoid or Use Alternate Drug.

• argatroban
  Serious - Use Alternative (1)piperacillin will increase the level or effect of argatroban by anticoagulation. Avoid or Use Alternate Drug. cephalosporins may decrease prothrombin activity

• aspirin
  Minor (1)piperacillin, aspirin. Either increases effects of the other by receptor binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug.

• aspirin rectal
  Minor (1)piperacillin will increase the level or effect of aspirin rectal by plasma protein binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug

• aspirin/citric acid/sodium bicarbonate
  Minor (1)piperacillin will increase the level or effect of aspirin/citric acid/sodium bicarbonate by plasma protein binding competition. Minor/Significance Unknown. Salicylic acid could be displaced from protein binding sites or it could itself displace other protein-bound drugs and result in an enhanced effect of the displaced drug

• atezolizumab
  Monitor Closely (1)piperacillin decreases effects of atezolizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• avelumab
  Monitor Closely (1)piperacillin decreases effects of avelumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• azithromycin
  Monitor Closely (1)azithromycin decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• balstilimab
  Monitor Closely (1)piperacillin decreases effects of balstilimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• bazedoxifene/conjugated estrogens
  Monitor Closely (1)piperacillin will decrease the level or effect of bazedoxifene/conjugated estrogens by altering intestinal flora. Applies only to oral forms of hormone. Low risk of contraceptive failure. Use Caution/Monitor.

• BCG vaccine live
  Serious - Use Alternative (1)piperacillin decreases effects of BCG vaccine live by pharmacodynamic antagonism. Contraindicated. Wait until antibiotic treatment complete to administer live bacterial vaccine; antibiotics may diminish therapeutic effects of BCG.

• bivalirudin
  Serious - Use Alternative (1)piperacillin will increase the level or effect of bivalirudin by anticoagulation. Avoid or Use Alternate Drug. cephalosporins may decrease prothrombin activity

• camrelizumab
  Monitor Closely (1)piperacillin decreases effects of camrelizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• cemiplimab
  Monitor Closely (1)piperacillin decreases effects of cemiplimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• chloramphenicol
  Monitor Closely (1)chloramphenicol decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• chlorothiazide
  Minor (1)chlorothiazide increases levels of piperacillin by decreasing renal clearance. Minor/Significance Unknown.

• cholera vaccine
  Serious - Use Alternative (1)piperacillin, cholera vaccine. pharmacodynamic antagonism. Avoid or Use Alternate Drug. Avoid coadministration of cholera vaccine with systemic antibiotics since these agents may be active against the vaccine strain. Do not administer cholera vaccine to patients who have received oral or parenteral antibiotics within 14 days prior to vaccination.

• choline magnesium trisalicylate
  Minor (1)piperacillin will increase the level or effect of choline magnesium trisalicylate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown. Salicylate saltscould be displaced from binding sites or could displace other highly protein-bound drugs such as penicillins

• clarithromycin
  Monitor Closely (1)clarithromycin decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• cosibelimab
  Monitor Closely (1)piperacillin decreases effects of cosibelimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• dalteparin
  Serious - Use Alternative (1)piperacillin increases effects of dalteparin by anticoagulation. Avoid or Use Alternate Drug. Piperacillin can inhibit platelet aggregation.

• demeclocycline
  Monitor Closely (1)demeclocycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• dichlorphenamide
  Monitor Closely (1)dichlorphenamide and piperacillin both decrease serum potassium. Use Caution/Monitor.

• dostarlimab
  Monitor Closely (1)piperacillin decreases effects of dostarlimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• doxycycline
  Monitor Closely (1)doxycycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• durvalumab
  Monitor Closely (1)piperacillin decreases effects of durvalumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• enoxaparin
  Serious - Use Alternative (1)piperacillin increases effects of enoxaparin by anticoagulation. Avoid or Use Alternate Drug. Piperacillin can inhibit platelet aggregation.

• erythromycin base
  Monitor Closely (1)erythromycin base decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• erythromycin ethylsuccinate
  Monitor Closely (1)erythromycin ethylsuccinate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• erythromycin lactobionate
  Monitor Closely (1)erythromycin lactobionate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• erythromycin stearate
  Monitor Closely (1)erythromycin stearate decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• gentamicin
  Minor (1)piperacillin increases effects of gentamicin by pharmacodynamic synergism. Minor/Significance Unknown.

• heparin
  Serious - Use Alternative (1)piperacillin will increase the level or effect of heparin by anticoagulation. Avoid or Use Alternate Drug. piperacillin can inhibit platelet aggregation

• hydrochlorothiazide
  Minor (1)hydrochlorothiazide increases levels of piperacillin by decreasing renal clearance. Minor/Significance Unknown.

• ibuprofen IV
  Minor (1)piperacillin will increase the level or effect of ibuprofen IV by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• meclofenamate
  Minor (1)piperacillin will increase the level or effect of meclofenamate by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• microbiota oral
  Serious - Use Alternative (1)piperacillin decreases effects of microbiota oral by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Microbiota oral contains bacterial spores. Antibacterial agents may decrease efficacy if coadministered. Complete antibiotic regimens 2-4 days before initiating microbiota oral. .

• minocycline
  Monitor Closely (1)minocycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• neomycin PO
  Minor (1)piperacillin increases effects of neomycin PO by pharmacodynamic synergism. Minor/Significance Unknown.

• nivolumab
  Monitor Closely (1)piperacillin decreases effects of nivolumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• omadacycline
  Serious - Use Alternative (1)omadacycline decreases effects of piperacillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.

• pembrolizumab
  Monitor Closely (1)piperacillin decreases effects of pembrolizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• penpulimab
  Monitor Closely (1)piperacillin decreases effects of penpulimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• probenecid
  Monitor Closely (1)probenecid will increase the level or effect of piperacillin by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

• retifanlimab
  Monitor Closely (1)piperacillin decreases effects of retifanlimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• rose hips
  Minor (1)rose hips will increase the level or effect of piperacillin by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• sarecycline
  Serious - Use Alternative (1)sarecycline decreases effects of piperacillin by pharmacodynamic antagonism. Avoid or Use Alternate Drug. Tetracyclines may interfere with the bactericidal action of penicillins. Monitor for decreased therapeutic effects of penicillins if concomitantly used with a tetracycline.

• sintilimab
  Monitor Closely (1)piperacillin decreases effects of sintilimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• sodium picosulfate/magnesium oxide/anhydrous citric acid
  Monitor Closely (1)piperacillin decreases effects of sodium picosulfate/magnesium oxide/anhydrous citric acid by altering metabolism. Use Caution/Monitor. Coadministration with antibiotics decreases efficacy by altering colonic bacterial flora needed to convert sodium picosulfate to active drug.

• streptomycin
  Minor (1)piperacillin increases effects of streptomycin by pharmacodynamic synergism. Minor/Significance Unknown.

• tetracycline
  Monitor Closely (1)tetracycline decreases effects of piperacillin by pharmacodynamic antagonism. Use Caution/Monitor. bacteriostatic agents may inhibit the effects of bactericidal agents.

• tislelizumab
  Monitor Closely (1)piperacillin decreases effects of tislelizumab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• tobramycin
  Minor (1)piperacillin increases effects of tobramycin by pharmacodynamic synergism. Minor/Significance Unknown.

• toripalimab
  Monitor Closely (1)piperacillin decreases effects of toripalimab by unspecified interaction mechanism. Use Caution/Monitor. Coadministration may interfere with therapeutic effects of immune checkpoint inhibitors.

• vancomycin
  Monitor Closely (1)piperacillin increases toxicity of vancomycin by unspecified interaction mechanism. Use Caution/Monitor. Monitor kidney function in patients concomitantly administered with piperacillin and vancomycin.

• vecuronium
  Monitor Closely (1)piperacillin increases toxicity of vecuronium by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Neuromuscular blockade may be prolonged.

• warfarin
  Monitor Closely (1)piperacillin, warfarin. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Platelet dysfunction occurs with extended-spectrum penicillins in varying degrees. Monitor INR and adjust warfarin dose if needed.

• willow bark
  Minor (1)piperacillin will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• xanomeline/trospium
  Monitor Closely (1)piperacillin, xanomeline/trospium. Either increases levels of the other by decreasing elimination. Use Caution/Monitor. Coadministration of trospium with other drugs eliminated by active tubular secretion may increase plasma concentrations of trospium and/or the concomitantly used drug owing to competition for this elimination pathway. Monitor for increased frequency and/or severity of adverse reactions.