Willow Bark (Herb/Suppl)

Extract

120-240 mg salicin PO TID-QID

Dried Bark

1-3 g PO TID-QID

Tea

1 cup PO TID-QID; prepared with 1-3 g bark/150 ml water

Liquid Extract

1-3 ml PO qDay; 1:1 25% alcohol

Contraindicated (0)

Serious - Use Alternative (2)

• measles, mumps, rubella and varicella vaccine, live

  willow bark, measles, mumps, rubella and varicella vaccine, live. Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. Risk of Reye's Syndrome with combination; avoid salicylate use for 6 wks after vaccination.

• varicella virus vaccine live

  willow bark, varicella virus vaccine live. Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. Risk of Reye's Syndrome with combination; avoid salicylate use for 6 wks after vaccination.

Monitor Closely (17)

• acetazolamide

  acetazolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.
  
  acetazolamide, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Use Caution/Monitor. Salicylate levels increased at moderate doses; risk of CNS toxicity. Salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• amoxicillin

  amoxicillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• ampicillin

  ampicillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• brinzolamide

  brinzolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.

• dicloxacillin

  dicloxacillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• griseofulvin

  griseofulvin decreases levels of willow bark by unknown mechanism. Use Caution/Monitor.

• methazolamide

  methazolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.

• methotrexate

  willow bark will increase the level or effect of methotrexate by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

• mycophenolate

  willow bark will increase the level or effect of mycophenolate by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.

• nafcillin

  nafcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• oxacillin

  oxacillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• penicillin G aqueous

  penicillin G aqueous, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• penicillin VK

  penicillin VK, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• pivmecillinam

  pivmecillinam, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• probenecid

  willow bark will increase the level or effect of probenecid by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
  
  willow bark decreases effects of probenecid by unknown mechanism. Use Caution/Monitor.

• temocillin

  temocillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• ticarcillin

  ticarcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

Minor (105)

• aceclofenac

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

• acemetacin

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

• acyclovir

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

• aluminum hydroxide

  aluminum hydroxide, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aminohippurate sodium

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

• ascorbic acid

  ascorbic acid will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark decreases levels of ascorbic acid by increasing renal clearance. Minor/Significance Unknown.
  
  ascorbic acid increases levels of willow bark by decreasing renal clearance. Minor/Significance Unknown.

• aspirin

  aspirin will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of aspirin by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• aspirin rectal

  willow bark increases effects of aspirin rectal by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.
  
  aspirin rectal will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• aspirin/citric acid/sodium bicarbonate

  aspirin/citric acid/sodium bicarbonate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of aspirin/citric acid/sodium bicarbonate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• balsalazide

  balsalazide will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of balsalazide by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• bendroflumethiazide

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

• budesonide

  budesonide decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• bumetanide

  willow bark, bumetanide. Other (see comment). Minor/Significance Unknown. Comment: Salicylates are less likely than other NSAIDs to interact w/bumetanide.

• calcium carbonate

  calcium carbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• cefaclor

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

• cefadroxil

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

• cefamandole

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

• cefazolin

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

• cefdinir

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

• cefditoren

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

• cefepime

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

• cefixime

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

• cefotaxime

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

• cefotetan

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

• cefpirome

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

• cefpodoxime

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

• cefprozil

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

• ceftazidime

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

• ceftibuten

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

• ceftriaxone

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

• celecoxib

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

• cephalexin

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

• chlorothiazide

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

• chlorpropamide

  willow bark will increase the level or effect of chlorpropamide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of chlorpropamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• chlorthalidone

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

• choline magnesium trisalicylate

  choline magnesium trisalicylate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of choline magnesium trisalicylate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• cortisone

  cortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• cyanocobalamin

  willow bark decreases levels of cyanocobalamin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• cyclopenthiazide

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

• deflazacort

  deflazacort decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• dexamethasone

  dexamethasone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• diclofenac

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

• diflunisal

  diflunisal will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of diflunisal by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• diltiazem

  diltiazem increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• ethanol

  ethanol increases toxicity of willow bark by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of GI bleeding.

• etodolac

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

• fenoprofen

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

• fludrocortisone

  fludrocortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• flurbiprofen

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

• folic acid

  willow bark decreases levels of folic acid by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• ganciclovir

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

• glimepiride

  willow bark increases effects of glimepiride by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• glipizide

  willow bark increases effects of glipizide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• glyburide

  willow bark increases effects of glyburide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• green tea

  green tea, willow bark. Other (see comment). Minor/Significance Unknown. Comment: Use caution when combining green tea with herbs that exhibit antiplatelet effects or anticoagulant activity.

• hydrochlorothiazide

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

• hydrocortisone

  hydrocortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• ibuprofen

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

• ibuprofen IV

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

• indapamide

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

• indomethacin

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

• insulin aspart

  willow bark increases effects of insulin aspart by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin detemir

  willow bark increases effects of insulin detemir by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin glargine

  willow bark increases effects of insulin glargine by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin glulisine

  willow bark increases effects of insulin glulisine by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin lispro

  willow bark increases effects of insulin lispro by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin NPH

  willow bark increases effects of insulin NPH by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin regular human

  willow bark increases effects of insulin regular human by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• ketoprofen

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

• ketorolac

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

• ketorolac intranasal

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

• L-methylfolate

  willow bark decreases levels of L-methylfolate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• lornoxicam

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

• meclofenamate

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

• mefenamic acid

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

• meloxicam

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

• mesalamine

  mesalamine will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of mesalamine by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• methyclothiazide

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

• methylprednisolone

  methylprednisolone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• metolazone

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

• nabumetone

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

• naproxen

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

• oxaprozin

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

• parecoxib

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

• piperacillin

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

• piroxicam

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

• prednisolone

  prednisolone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• prednisone

  prednisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• rose hips

  rose hips will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark decreases levels of rose hips by increasing renal clearance. Minor/Significance Unknown.
  
  rose hips increases levels of willow bark by decreasing renal clearance. Minor/Significance Unknown.

• salicylates (non-asa)

  salicylates (non-asa) will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of salicylates (non-asa) by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• salsalate

  salsalate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of salsalate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• sodium bicarbonate

  sodium bicarbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• sodium citrate/citric acid

  sodium citrate/citric acid, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• sulfadiazine

  willow bark increases levels of sulfadiazine by unspecified interaction mechanism. Minor/Significance Unknown.

• sulfamethoxazole

  willow bark increases levels of sulfamethoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

• sulfasalazine

  sulfasalazine will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of sulfasalazine by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• sulfisoxazole

  willow bark increases levels of sulfisoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

• sulindac

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

• tolazamide

  willow bark increases effects of tolazamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• tolbutamide

  willow bark increases effects of tolbutamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• tolfenamic acid

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

• tolmetin

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

• triamcinolone acetonide injectable suspension

  triamcinolone acetonide injectable suspension decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• valganciclovir

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

• verapamil

  verapamil increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• aceclofenac

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

• acemetacin

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

• acetazolamide

  Monitor Closely (2)acetazolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.
  
  acetazolamide, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Use Caution/Monitor. Salicylate levels increased at moderate doses; risk of CNS toxicity. Salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• acyclovir

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

• aluminum hydroxide

  Minor (1)aluminum hydroxide, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• aminohippurate sodium

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

• amoxicillin

  Monitor Closely (1)amoxicillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• ampicillin

  Monitor Closely (1)ampicillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• ascorbic acid

  Minor (3)ascorbic acid will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark decreases levels of ascorbic acid by increasing renal clearance. Minor/Significance Unknown.
  
  ascorbic acid increases levels of willow bark by decreasing renal clearance. Minor/Significance Unknown.

• aspirin

  Minor (2)aspirin will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of aspirin by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• aspirin rectal

  Minor (2)willow bark increases effects of aspirin rectal by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.
  
  aspirin rectal will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.

• aspirin/citric acid/sodium bicarbonate

  Minor (2)aspirin/citric acid/sodium bicarbonate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of aspirin/citric acid/sodium bicarbonate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• balsalazide

  Minor (2)balsalazide will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of balsalazide by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• bendroflumethiazide

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

• brinzolamide

  Monitor Closely (1)brinzolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.

• budesonide

  Minor (1)budesonide decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• bumetanide

  Minor (1)willow bark, bumetanide. Other (see comment). Minor/Significance Unknown. Comment: Salicylates are less likely than other NSAIDs to interact w/bumetanide.

• calcium carbonate

  Minor (1)calcium carbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• cefaclor

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

• cefadroxil

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

• cefamandole

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

• cefazolin

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

• cefdinir

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

• cefditoren

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

• cefepime

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

• cefixime

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

• cefotaxime

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

• cefotetan

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

• cefpirome

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

• cefpodoxime

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

• cefprozil

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

• ceftazidime

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

• ceftibuten

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

• ceftriaxone

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

• celecoxib

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

• cephalexin

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

• chlorothiazide

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

• chlorpropamide

  Minor (2)willow bark will increase the level or effect of chlorpropamide by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of chlorpropamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• chlorthalidone

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

• choline magnesium trisalicylate

  Minor (2)choline magnesium trisalicylate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of choline magnesium trisalicylate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• cortisone

  Minor (1)cortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• cyanocobalamin

  Minor (1)willow bark decreases levels of cyanocobalamin by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• cyclopenthiazide

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

• deflazacort

  Minor (1)deflazacort decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• dexamethasone

  Minor (1)dexamethasone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• diclofenac

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

• dicloxacillin

  Monitor Closely (1)dicloxacillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• diflunisal

  Minor (2)diflunisal will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of diflunisal by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• diltiazem

  Minor (1)diltiazem increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.

• ethanol

  Minor (1)ethanol increases toxicity of willow bark by pharmacodynamic synergism. Minor/Significance Unknown. Increased risk of GI bleeding.

• etodolac

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

• fenoprofen

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

• fludrocortisone

  Minor (1)fludrocortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• flurbiprofen

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

• folic acid

  Minor (1)willow bark decreases levels of folic acid by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• ganciclovir

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

• glimepiride

  Minor (1)willow bark increases effects of glimepiride by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• glipizide

  Minor (1)willow bark increases effects of glipizide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• glyburide

  Minor (1)willow bark increases effects of glyburide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• green tea

  Minor (1)green tea, willow bark. Other (see comment). Minor/Significance Unknown. Comment: Use caution when combining green tea with herbs that exhibit antiplatelet effects or anticoagulant activity.

• griseofulvin

  Monitor Closely (1)griseofulvin decreases levels of willow bark by unknown mechanism. Use Caution/Monitor.

• hydrochlorothiazide

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

• hydrocortisone

  Minor (1)hydrocortisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• ibuprofen

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

• ibuprofen IV

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

• indapamide

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

• indomethacin

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

• insulin aspart

  Minor (1)willow bark increases effects of insulin aspart by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin detemir

  Minor (1)willow bark increases effects of insulin detemir by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin glargine

  Minor (1)willow bark increases effects of insulin glargine by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin glulisine

  Minor (1)willow bark increases effects of insulin glulisine by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin lispro

  Minor (1)willow bark increases effects of insulin lispro by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin NPH

  Minor (1)willow bark increases effects of insulin NPH by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• insulin regular human

  Minor (1)willow bark increases effects of insulin regular human by pharmacodynamic synergism. Minor/Significance Unknown. Large dose of salicylate.

• ketoprofen

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

• ketorolac

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

• ketorolac intranasal

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

• L-methylfolate

  Minor (1)willow bark decreases levels of L-methylfolate by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown.

• lornoxicam

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

• measles, mumps, rubella and varicella vaccine, live

  Serious - Use Alternative (1)willow bark, measles, mumps, rubella and varicella vaccine, live. Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. Risk of Reye's Syndrome with combination; avoid salicylate use for 6 wks after vaccination.

• meclofenamate

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

• mefenamic acid

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

• meloxicam

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

• mesalamine

  Minor (2)mesalamine will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of mesalamine by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• methazolamide

  Monitor Closely (1)methazolamide, willow bark. Either increases levels of the other by Other (see comment). Use Caution/Monitor. Comment: Carbonic anhydrase inhibitors (CAIs) and salicylates inhibit each other's renal tubular secretion, resulting in increased plasma levels. CAIs also shift salicylates from plasma to the CNS, leading to potential neurotoxicity.

• methotrexate

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

• methyclothiazide

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

• methylprednisolone

  Minor (1)methylprednisolone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• metolazone

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

• mycophenolate

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

• nabumetone

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

• nafcillin

  Monitor Closely (1)nafcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• naproxen

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

• oxacillin

  Monitor Closely (1)oxacillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• oxaprozin

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

• parecoxib

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

• penicillin G aqueous

  Monitor Closely (1)penicillin G aqueous, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• penicillin VK

  Monitor Closely (1)penicillin VK, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• piperacillin

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

• piroxicam

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

• pivmecillinam

  Monitor Closely (1)pivmecillinam, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• prednisolone

  Minor (1)prednisolone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• prednisone

  Minor (1)prednisone decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• probenecid

  Monitor Closely (2)willow bark will increase the level or effect of probenecid by acidic (anionic) drug competition for renal tubular clearance. Use Caution/Monitor.
  
  willow bark decreases effects of probenecid by unknown mechanism. Use Caution/Monitor.

• rose hips

  Minor (3)rose hips will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark decreases levels of rose hips by increasing renal clearance. Minor/Significance Unknown.
  
  rose hips increases levels of willow bark by decreasing renal clearance. Minor/Significance Unknown.

• salicylates (non-asa)

  Minor (2)salicylates (non-asa) will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of salicylates (non-asa) by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• salsalate

  Minor (2)salsalate will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of salsalate by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• sodium bicarbonate

  Minor (1)sodium bicarbonate, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• sodium citrate/citric acid

  Minor (1)sodium citrate/citric acid, willow bark. Mechanism: passive renal tubular reabsorption due to increased pH. Minor/Significance Unknown. Salicylate levels increased at moderate doses; salicylate levels decreased at large doses (d/t increased renal excretion of unchanged salicylic acid).

• sulfadiazine

  Minor (1)willow bark increases levels of sulfadiazine by unspecified interaction mechanism. Minor/Significance Unknown.

• sulfamethoxazole

  Minor (1)willow bark increases levels of sulfamethoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

• sulfasalazine

  Minor (2)sulfasalazine will increase the level or effect of willow bark by acidic (anionic) drug competition for renal tubular clearance. Minor/Significance Unknown.
  
  willow bark increases effects of sulfasalazine by pharmacodynamic synergism. Minor/Significance Unknown. Willow bark contains salicylic acid, which may have additive effects/toxicity with salicylate drugs.

• sulfisoxazole

  Minor (1)willow bark increases levels of sulfisoxazole by unspecified interaction mechanism. Minor/Significance Unknown.

• sulindac

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

• temocillin

  Monitor Closely (1)temocillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• ticarcillin

  Monitor Closely (1)ticarcillin, willow bark. Either increases levels of the other by decreasing renal clearance. Use Caution/Monitor.

• tolazamide

  Minor (1)willow bark increases effects of tolazamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• tolbutamide

  Minor (1)willow bark increases effects of tolbutamide by plasma protein binding competition. Minor/Significance Unknown. Large dose of salicylate.

• tolfenamic acid

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

• tolmetin

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

• triamcinolone acetonide injectable suspension

  Minor (1)triamcinolone acetonide injectable suspension decreases levels of willow bark by increasing renal clearance. Minor/Significance Unknown.

• valganciclovir

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

• varicella virus vaccine live

  Serious - Use Alternative (1)willow bark, varicella virus vaccine live. Mechanism: unspecified interaction mechanism. Avoid or Use Alternate Drug. Risk of Reye's Syndrome with combination; avoid salicylate use for 6 wks after vaccination.

• verapamil

  Minor (1)verapamil increases effects of willow bark by unknown mechanism. Minor/Significance Unknown. Enhanced antiplatelet activity.