Clarithromycin 4- .Antihistamines

PROPAFENONE I. ANTIARRHYTHMICS - disopyra-mide, procainamide 2. ANTIBIOTICS - macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfopristin 3. ANTICANCER AND IMMUNOMODULATING DRUGS -arsenic trioxide 4. ANTIDEPRESSANTS - TCAs, venlafaxine 5. ANTIEMETICS-dolasetron 6. ANTIFUNGALS-fluconazole, posaconazole, voriconazole 7. ANTIHISTAMINES - terfenadine, hydroxyzine, mizolastine 8. ANTI-M ALARIALS - artemether with lumefantrine, chloroquine, hydroxychloroquine, mefloquine, quinine 9. ANTIPROTOZOALS - pentamidine isetionate 10. ANTIPSYCHOTICS-atypicals, phenothiazines, pimozide II. BETA-BLOCKERS - sotalol 12. BRONCHODILATORS -parenteral bronchodilators 13. CNS STIMULANTS - atomoxetine Risk of ventricular arrhythmias, particularly torsades de pointes Additive effect these drugs prolong the Q-T interval. Also, amitriptyline, clomipramine and desipramine levels may be t by propafenone. Amitriptyline and clomipramine may t propafenone levels. Propafenone and these TCAs inhibit CYP2D6-mediated metabolism of each other Avoid co-administration... 

ANTIBIOTICS-macrolides (especially azithromycin, clarithromycin, parenteral erythromycin, telithromycin), quinolones (especially moxifloxacin), quinupristin/ dalfbpristin 3. ANTIDEPRESSANTS - TCAs, venlafaxine 4. ANTI EMETICS -dolasetron 5. ANTIFUNGALS-fluconazole, posaconazole, voriconazole 6. ANTIHISTAMINES - terfenadine, hydroxyzine, mizolastine... 

Non-sedating antihistamines (e.g. loratidine, e.g. Clarityn cetirizine, e.g. Benadryl, Piriteze, Zirtek clemastine), which can cause dangerous arrhythmias with antifungal agents (itraconazole, ketoconazole), antibiotics (erythromycin, clarithromycin) and drugs used to counteract acidity... 

Macrolide antibiotics are contraindicated in patients with known hypersensitivity or intolerance to any macrolide. Because clarithromycin can have adverse effects on embryo-fetal development in animals, this drug should be avoided in pregnant women unless no other therapy is appropriate. Concurrent administration of the macrolides and astemizole or terfenadine can cause elected antihistamine levels, resulting in life-threatening cardiac arrhythmias, and should be avoided. 

Bismuth-containing preparations (e.g., those containing colloidal bismuth subcitrate) have effects similar to those of sucralfate, apparently because of their similar physical properties and coating effects. A combination of ranitidine-bismuth citrate is used with clarithromycin for eradication of H. pylori in the treatment and prevention of recurrence of duodenal ulcers. Combinations of bismuth subcitrate with other antibiotics and with H2 antihistamines also are used. Bismuth subsalicylate is used in this way as well. 

Some macrolides (particularly erythromycin and clarithromycin) appear to reduce the metabolism of terfenadine and astemizole by inhibition of the cytochrome P450 isoenzyme CYP3A. High serum levels of astemizole and terfenadine cause a prolongation of the QT interval and may precipitate the development of torsade de pointes arrhythmia, see Table 15.2 , (p.583). The risk of cardiac arrhythmias with other non-sedating antihistamines appears to be non-existent or very much lower (see Table... 

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