Acenocoumarol
Adverse Effect: An increased risk of bleeding Clinical Management: In patients receiving oral anticoagulant therapy with acenocoumarol, the prothrombin time ratio or international normalized ratio (INR) should be closely monitored with the addition and withdrawal of treatment with clarithromycin, and should be reassessed periodically during concurrent therapy. Adjustments of the acenocoumarol dose may be necessary in order to maintain the desired level of anticoagulation.
Alprazolam
Adverse Effect: increased alprazolam toxicity (CNS depression, ataxia, lethargy) Clinical Management: Observe patients receiving Clarithromycin and alprazolam for enhanced CNS effects.Dose reduction by 50% to 75% may be required.
Astemizole
Adverse Effect: cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Clinical Management: The concurrent use of astemizole and clarithromycin is contraindicated.
Atorvastatin
Adverse Effect: an increased risk of myopathy or rhabdomyolysis Clinical Management:If concurrent therapy is required, monitor the patient for signs and symptoms of myopathy or rhabdomyolysis .
Carbamazepine
Adverse Effect: An increased risk of carbamazepine toxicity (ataxia, nystagmus, diplopia, headache, vomiting, apnea, seizures, coma) Clinical Management: Decreasing the carbamazepine dose by approximately 25% is advised at the initiation of clarithromycin therapy with further modification according to clinical symptoms and serum carbamazepine trough concentrations.
Cimetidine
Adverse Effect: Reduced clarithromycin efficacy Clinical Management: Until more information becomes available, it would be prudent to advise patients to separate the administration of cimetidine and clarithromycin as much as possible.
Cisapride
Aadverse Effect: cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Clinical Management: Coadministration of cisapride with clarithromycin is contraindicated. Serious, even fatal, adverse cardiac events have been reported when these agents were given concomitantly.
Cyclosporin
Adverse Effect: Increases Cyclosporine concentrations Clinical Management: Monitor Cyclosporine concentrations and adjust the dosage accordingly.
Diazepam
Adverse Effect: increased Diazepam toxicity (CNS depression, ataxia, lethargy) Clinical Management: Observe patients receiving concurrent therapy with Clarithromycin and Diazepam for enhanced CNS effects. Warn patients regarding potential for drug hangover.
Digoxin
Adverse Effect: Digoxin toxicity (nausea, vomiting, arrhythmias) Clinical Management: If possible, antibiotics known to inhibit the conversion of digoxin to inactive metabolites (clarithromycin, erythromycin, tetracycline) should be avoided in patients on digoxin therapy. Another alternative would be to administer digoxin parenterally, since this interaction is not expected to occur when the gut is bypassed. In cases where clarithromycin therapy must be given with oral digoxin, a temporary digoxin dose reduction should be considered. Close monitoring of digoxin serum levels is recommended.
Dihydroergotoxine
Adverse Effect: Acute ergotism (nausea, vomiting, vasospastic ischemia) Clinical Management: Concomitant use is not recommended. However, patients receiving dihydroergotamine and clarithromycin should be monitored for increased ergot toxicity (nausea, vomiting, vasospastic ischemia).
Efavirenz
Adverse Effect: Rashes, decrease in plasma concentration of Clarithromycin Clinical Management: Use other macrolide antibiotic like Azithromycin if possible.
Ergotamine
Adverse Effect: acute ergotism (nausea, vomiting, vasospastic ischemia) Clinical Management: Concomitant use is not recommended. However, patients receiving dihydroergotamine and clarithromycin should be monitored for increased ergot toxicity (nausea, vomiting, vasospastic ischemia).
Fluoxetine
Adverse Effect: delirium and psychosis Clinical Management: Clarithromycin should be avoided in patients treated with fluoxetine.
Itraconazole
Adverse Effect: Increased itraconazole and clarithromycin concentrations Clinical Management: Monitor patients for signs and symptoms of itraconazole and clarithromycin toxicity.
Lansoprazole
Adverse Effect: Glossitis, stomatitis, or black tongue Clinical Management: When lansoprazole is used with clarithromycin monitor patients for changes in the oral mucosa. Discontinue the clarithromycin and reduce the dose of lansoprazole if needed.
Lovastatin
Adverse Effect: an increased risk of myopathy or rhabdomyolysis Clinical Management:If concurrent therapy is required, monitor the patient for signs and symptoms of myopathy or rhabdomyolysis .
Midazolam
Adverse Effect: increased Midazolam toxicity (CNS depression, ataxia, lethargy) Clinical Management: Observe patients receiving clarithromycin and midazolam for enhanced central nervous system effects. Warn patients regarding the potential for drug hangover.
Omeprazole
Adverse Effect: Increased bioavailability of both agents
Pimozide
Adverse Effect: Increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Clinical Management: Concurrent use of pimozide and clarithromycin is contraindicated.
Simvastatin
Adverse Effect: an increased risk of myopathy or rhabdomyolysis Clinical Management:If concurrent therapy is required, monitor the patient for signs and symptoms of myopathy or rhabdomyolysis .
Terfenadine
Adverse Effect: cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Clinical Management: Concomitant use of clarithromycin and terfenadine is contraindicated.
Theophylline
Adverse Effect: Theophylline toxicity (nausea, vomiting, palpitations, seizures) Clinical Management: Theophylline serum concentrations should be closely monitored when clarithromycin is added, discontinued, or when dosing changes occur. Dosing adjustments of theophylline may be necessary.
Verapamil
Adverse Effect: Increased verapamil plasma concentrations and an increased risk of hypotension and/or bradycardia Clinical Management: Monitor patient for hypotension and adjust doses of verapamil accordingly.
Warfarin
Adverse Effect: An increased risk of bleeding Clinical Management: In patients receiving oral anticoagulant therapy with warfarin, the prothrombin time ratio or international normalized ratio (INR) should be closely monitored with the addition and withdrawal of treatment with clarithromycin, and should be reassessed periodically during concurrent therapy. Adjustments of the warfarin dose may be necessary in order to maintain the desired level of anticoagulation.
Zidovudine
Adverse Effect: Decreased zidovudine concentrations Clinical Management: If an interaction is suspected (ie, sub-therapeutic response to zidovudine after initiating clarithromycin), consider increasing the dose of zidovudine.
Carbamazepine, theophylline: In-creased serum levels of these drugs. Monitor plasma levels carefully.
Cyclosporine, phenytoin, triazolam: Decreased metabolism of these drugs. Monitor patient close-ly.
Digoxin: Increased digoxin levels. Monitor digox-in level.
Dihydroergotamine, ergotamine: Ergot toxicity. Monitor patient closely.
Warfarin: Increased PT. Monitor PT closely. |