Warfarin Clindamycin

Ceftriaxone (A) Clindamycin (A) Clofibrate (A) Dexamethasone (N) Diazepam (B) Diazoxide (A) Dicloxacillin (N) Digitoxin (N) Etoposide (N) Ibuprofen (A) Indomethacin (A) Nafcillin (A) Naproxen (A) Oxacillin (A) Phenylbutazone (A) Phenytoin (A) Probenecid (A) Salicylic acid (A) Sulfisoxazole (A) Teniposide (N) Thiopental (A) Tolbutamide (A) Valproic acid (A) Warfarin (A)... 

Warfarin absorption by rat intestine in vitro was reported not to be affected by kaolin. With clindamycin, the rate (but not the amount) of absorption was affected by kaolin. ... 

Clinically important, potentially hazardous interactions with alfentanil, aminophylline, amisulpride, amoxicillin, ampicillin, anticonvulsants, astemizole, atorvastatin, benzodiazepines, bromocriptine, buprenorphine, bupropion, carbamazepine, cilostazol, ciprofloxacin, cisapride, clindamycin, colchicine, cyclosporine, dasatinib, digoxin, dihydroergotamine, diltiazem, disopyramide, enoxacin, eplerenone, ergotamine, eszopiclone, everolimus, fluconazole, fluoxetine, fluvastatin, gatifloxacin, HMG-CoA reductase inhibitors, imatinib, itraconazole, ketoconazole, lomefloxacin, lorazepam, lovastatin, methadone, methylprednisolone, methysergide, midazolam, mizolastine, moxifloxacin, nitrazepam, norfloxacin, ofloxacin, paroxetine, pimozide, pravastatin, quinolones, ranolazine, repaglinide, rupatadine, sertraline, sildenafil, simvastatin, sparfloxacin, sulpiride, tacrolimus, terfenadine, triazolam, troleandomycin, vardenafil, verapamil, vinblastine, warfarin, zaleplon, zolpidem, zuclopenthixol... 

Noninterfering acetaminophen, N-acetylprocainamide, amikacin, amitriptyline, amlodi-pine, carbamazepine, cefotaxime, ceftazidime, chloramphenicol, ciprofloxacin, cisapride, clindamycin, clonidine, codeine, cyclosporine, digoxin, diphenhydramine, disopyramide, ethosuximide, fluconazole, gentamicin, gentamicin, heparin, labetalol, levothyroxine, li-docaine, lithium, methotrexate, metronidazole, minoxidil, nafcillin, nifedipine, phenobar-bital, phenobarbital, phenytoin, phenytoin, primidone, procainamide, propranolol, quini-dine, ranitidine, salicylic acid, theophylline, tobramycin, tobramycin, valproic acid, warfarin... 

Chloramphenicol also causes a decrease in the therapeutic effect of clindamycin, erythromycin, or lincomycin. Chloramphenicol increases the drug serum levels of phenobarbital (Luminal), phenytoin (Dilantin), or warfarin (Coumadin) which can lead to toxicity. 

An isolated report describes bleeding and a markedly increased INR in a woman stabilised on warfarin, which was tentatively attributed to an interaction with clindamycin. Another report found no cases of a serious increase in INR in patients taking acenocoumarol or phenprocoumon with clindamycin. 

A 47-year-old woman with multiple medical problems stabilised on warfarin (and also taking azathioprine, captopril, furosemide, insulin, capto-pril, prednisone, levothyroxine, valproic acid and zolpidem) had all her teeth removed under general anaesthetic. Sixteen days later she needed a dental abscess drained and was given oral clindamycin 300 mg four times daily with ibuprofen 600 mg for any discomfort. On day 17 she needed a suture to stop some bleeding and her INR was found to be 3.5. By day 20 she had developed more severe oral bleeding, which needed emergency room treatment. Her INR was found to have risen to 13 and her haemat-ocrit decreased to 18%. She was treated successfully with a blood transfusion and vitamin K. ... 

A probable warfarin and dapsone interaction was also reported in a case study of a 41-year-old woman who exhibited a supratherapeutic INR when taking clindamycin and dapsone for an infection on her right foot. An interaction between warfarin and dapsone was identified using Lexi-Comp, and it is hypothesized that warfarin and dapsone may compete for binding on the CYP2C9 and CYP3A4 isozymes, resulting in serum elevation of warfarin levels [lO ]. 

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