Carbamazepine Calcium-channel blockers

Anxiolytics clonazepam, diazepam, temazepam, triazolam, alprazolam, midazolam, buspirone Anticonvulsants ethosuximide, carbamazepine Calcium channel blockers diltiazem, felodipine, nifedipine, verapamil... 

CARBAMAZEPINE CALCIUM CHANNEL BLOCKERS Diltiazem and verapamil T plasma concentrations of carbamazepine (have been cases of toxicity) Diltiazem and verapamil inhibit CYP3A4-mediated metabolism of carbamazepine. They also inhibit intestinal P-gp, which may t bioavailability of carbamazepine Monitor carbamazepine levels when initiating calcium channel blockers, particularly diltiazem/verapamil... 

Other agents are also used for the treatment of manic-depressive disorders based on preliminary clinical results (177). The antiepileptic carbamazepine [298-46-4] has been reported in some clinical studies to be therapeutically beneficial in mild-to-moderate manic depression. Carbamazepine treatment is used especially in bipolar patients intolerant to lithium or nonresponders. A majority of Hthium-resistant, rapidly cycling manic-depressive patients were reported in one study to improve on carbamazepine (178). Carbamazepine blocks noradrenaline reuptake and inhibits noradrenaline exocytosis. The main adverse events are those found commonly with antiepileptics, ie, vigilance problems, nystagmus, ataxia, and anemia, in addition to nausea, diarrhea, or constipation. Carbamazepine can be used in combination with lithium. Several clinical studies report that the calcium channel blocker verapamil [52-53-9] registered for angina pectoris and supraventricular arrhythmias, may also be effective in the treatment of acute mania. Its use as a mood stabilizer may be unrelated to its calcium-blocking properties. Verapamil also decreases the activity of several neurotransmitters. Severe manic depression is often treated with antipsychotics or benzodiazepine anxiolytics. 

Alternate treatments. Mood-stabilization and control of manic or hy-pomanic episodes in some subtypes of bipolar illness may also be achieved with the anticonvulsants valproate and carbamazepine, as well as with calcium channel blockers (e.g., verapamil, nifedipine, nimodipine). Effects are delayed and apparently unrelated to the mechanisms responsible for anticonvulsant and cardiovascular actions, respectively. 

Drugs that may affect repaglinide include CYP 450 inhibitors (eg, clarithromycin, erythromycin, ketoconazole, miconazole), CYP 450 inducers (eg, barbiturates, carbamazepine, rifampin), beta blockers, calcium channel blockers, chloramphenicol, corticosteroids, coumarins, estrogens, gemfibrozil, isoniazid, itraconazole, levonorgestrel and ethinyl estradiol, MAOIs, nicotinic acid, NSAIDs, oral contraceptives, phenothiazines, phenytoin, probenecid, salicylates, simvastatin, sulfonamides, sympathomimetics, thiazides and other diuretics, and thyroid products. 

Agents that may increase theophylline levels include allopurinol, beta blockers (nonselective), calcium channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, influenza virus vaccine, interferon, macrolides, mexiletine, quinolones, thiabendazole, thyroid hormones, carbamazepine, isoniazid, and loop diuretics. 

Drugs that may affect tacrolimus include nephrotoxic agents (aminoglycosides, amphotericin B, cisplatin, cyclosporine), antifungals, bromocriptine, calcium channel blockers, cimetidine, clarithromycin, danazol, diltiazem, erythromycin, methylprednisolone, metoclopramide, carbamazepine, phenobarbital, phenytoin, rifamycins, cisapride, chloramphenicol, metronidazole, nefazodone, omeprazole, protease inhibitors, macrolide antibiotics, fosphenytoin, and St. John s wort. 

Drugs that may affect cyclosporine include allopurinol, amiodarone, androgens (eg, danazol, methyltestosterone), anticonvulsants (eg, carbamazepine, phenobarbital, phenytoin), azole antifungals (eg, fluconazole, ketoconazole), beta-blockers, bosentan, bromocriptine, calcium channel blockers, colchicine, oral contraceptives, corticosteroids, fluoroquinolones (eg, ciprofloxacin), foscarnet, HMG-CoA reductase inhibitors, imipenem-cilastatin, macrolide antibiotics, methotrexate, metoclopramide, nafcillin, nefazodone, orlistat, potassium-sparing diuretics, probucol, rifamycins (rifampin, rifabutin), serotonin reuptake inhibitors (SSRIs eg, fluoxetine, sertraline),... 

Oarbamazepine is increasingly recognized as an effective treatment for bipolar affective illness, whereas the data on nimodipine and related calcium channel blockers [CCBs] are much more preliminary. In this chapter, we review data on the efficacy and putative mechanisms of action of carbamazepine and nimodipine in the recurrent affective disorders. 

FKiURE 6 5C. Efficacy of dihydropyridine L-type calcium channel blockers. Mean deviation from euthymia ratings (number of days in parentheses) in a patient with bipolar 11 disorder with ultra-ultrarapid cycling showing the following efficacy of nimodipine monotherapy efficacy of nimodipine-carbamazepine combination therapy unsuccessful transition from nimodipine to verapamil successful reinstitution of nimodipine-carbamazepine combination therapy and, finally, successful transition to isradipine-carbamazepine combination therapy. P <. 05 "nimodipine slowly tapered to zero. 

Carbamazepine [P] Decreased carbamazepine metabolism with diltiazem and verapamil possible increase in calcium channel blocker metabolism. 

Antidepressants, tricyclic Beta-adrenoceptor blockers Calcium channel blockers Carbamazepine. 

CALCIUM CHANNEL BLOCKERS CARBAMAZEPINE 1. Diltiazem and verapamil T plasma concentrations of carbamazepine (cases of toxicity) 2.1 plasma concentrations of felodipine, nifedipine and possibly nimodipine and nisoldipine 1. Diltiazem and verapamil inhibit CYP3A4-mediated metabolism of carbamazepine. They also inhibit intestinal P-gp, which may t the bioavailability of carbamazepine 2. Carbamazepine, in turn, induces CYP3A4, which metabolizes calcium channel blockers 1. Monitor carbamazepine levels when initiating calcium channel blockers, particularly diltiazem and verapamil 2. Monitor PR and BP closely watch for T BP when starting carbamazepine in patients already on calcium channel blockers... 

A pharmacokinetic interaction has been described between carbamazepine and the calcium channel blockers... 

All anticonvulsants (except gabapentin), atypical antipsychotics, benzodiazepines, and calcium channel blockers require liver metabolism, and dosage adjustments may be needed (e.g., 25-50% reduction of normal doses) Carbamazepine or oxcarbazepine Alternative lamotrigine Acute mania or mixed episode first choice lithium... 

After first trimester carbamazepine, lamotrigine, oxcarbazepine, or valproate Second choice benzodiazepine (lorazepam) Third choice calcium channel blocker With psychosis first choice adjunctive high-potency typical antipsychotic (haloperidol, perphenazine, thiothixene, or trifluoperazine)... 

Calcium-channel blockers Diltiazem and verapamil have inhibitory effects on hepatic microsomal enzymes, and so can increase serum levels of carbamazepine. Nifedipine has not been studied as well as the other calcium-channel blockers, but present data suggest that it probably does not interact significantly with carbamazepine. 

CYP3A4 alprazolam, calcium channel blockers, cisapride, clarithromycin, cyclosporin A, erythromycin, HIV protease inhibitors, lidocaine, midazolam, simvastatin, terfenadine carbamazepine, dexamethsone, phenobarbital, phenytoin, rifampicin, St John s wort cimetidine, erythromycin, grapefruit juice, HIV protease inhibitors, itraconazole, ketoconazole... 

A4 Barbiturates, carbamazepine, corticosteroids, efavirenz, phenytoin, rifampin, troglitazone Antiarrhythmics, antidepressants, azole antifungals, benzc iazepines, calcium channel blockers, cyclosporine, delavirdine, doxorubicin, efavirenz, erythromycin, estrogens, HIV protease inhibitors, nefazodone, paclitaxel, proton pump inhibitors, HMG-CoA reductase inhibitors, rifabutin, rifampin, sildenafil, SSRIs, tamoxifen, trazodone, vinca anticancer agents... 

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