Ritonavir with itraconazole

ITRACONAZOLE, KETOCONAZOLE PROTEASE INHIBITORS Possibly t levels of ketoconazole by amprenavir, indinavir and ritonavir (with or without lopinavir). Conversely, indinavir, ritonavir and saquinavir levels t by itraconazole and ketoconazole Inhibition of, or competition for, CYP3A4-mediated metabolism Use itraconazole with caution and monitor for adverse effects. No dose adjustment is recommended for doses <400 mg/day of ketoconazole... 

Clinically important, potentially hazardous interactions with itraconazole, ketoconazole, nelfinavir, ritonavir... 

The information about the interactions of protease inhibitors with itraconazole is limited. On the basis of the available data, it is possible that itraconazole has greater effects than ketoconazole , (below), on protease inhibitor levels. The manufacturers of indinavir advise modestly reducing the indinavir dose to 600 mg every 8 hours if it is to be given with itraconazole. The UK manufacturer of saquinavir recommends monitoring for saquinavir toxicity if itraconazole is used. Some protease inhibitors, especially ritonavir and possibly indinavir, may increase itraconazole levels and most manufacturers say that doses of itraconazole greater than 200 mg a day are not recommended. The US manufacturers of amprenavir recommend increased monitoring for adverse effects and state that the dose of itraconazole may need to be reduced if it is greater than 400 mg daily. ... 

Cardiovascular system Acute congestive heart failure and fatal asystole have been attributed to itraconazole [16 ]. A 22-year-old-man with asymptomatic HTV infection treated with zidovudine, lamivudine and lopinavir/ritonavir was treated with itraconazole (200 mg three hmes daily for 2 days followed by 200 mg twice daily) after initial improvement from Histoplasma capsulatum infection requiring ICU treatment. 

Sildenafil doses should be decreased when any potent cytochrome P450 3A4 inhibitor is used (e g., cimetidine, erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir, and saquinavir). Vardenafil doses vary accordingto which agent is used (2.5 mg q 72 h for ritonavir, 2.5 mg q 24 h for indinavir, ketoconazole 400 mg daily, and itraconazole 400 mg daily and 5 mg q 24 h for ketoconazole 200 mg daily, itraconazole200 mg daily, and erythromycin). Tadalafil doses are reduced only when it is used with the most potent cytochrome P450 3A4 inhibitors (e g., ketoconazole or ritonavir). 

Hypersensitivity to quinazolines (eg, doxazosin, prazosin, terazosin) moderate or severe hepatic insufficiency coadministration with potent CYP3A4 inhibitors (eg, ketoconazole, itraconazole, ritonavir). 

All patients with the following conditions Serum potassium greater than 5.5 mEq/L at initiation Ccr 30 mL/min or less concomitant use with the following potent CYP3A4 inhibitors Ketoconazole, itraconazole, nefazodone, troleandomycin, clarithromycin, ritonavir, and nelfinavir. 

Pregnancy (ergotamine s powerful uterine stimulant actions may cause fetal harm) hypersensitivity to ergot alkaloids peripheral vascular disease (eg, thromboangiitis obliterans, leutic arteritis, severe arteriosclerosis, thrombophlebitis, Raynaud s disease) hepatic or renal impairment severe pruritus coronary artery disease hypertension sepsis. The use of potent CYP3A4 inhibitors (ritonavir, nelfinavir, indinavir, erythromycin, clarithromycin, troleandomycin, ketoconazole, itraconazole) with dihydroergotamine is contraindicated. 

HIV infection (in combination with other antiretrovirals) PO 800 mg (two 400-mg capsules) q8h. Dosage adjustments when given concomitantly Delavirdine, itraconazole, ketoconazok Reduce dose to 600 mg q8h. Efavirenz-. Increase dose to 1,000 mg q8h. Lopinavir/ritonavir Reduce dose to 600 mg twice a day. Nevirapine-. Increase dose to 1,000 mgqSh. Rifabutin-. Reduce rifabutin by lA and increase indinavir to 1,000 mg q8h. Ritonavir 100-200 mg twice a day and indinavir 800 mg twice a day or ritonavir 400 mg twice a day and indinavir 400 mg twice a day. 

The buffer in didanosine tablets and powder interferes with absorption of indinavir, delavirdine, atazanavir, dapsone, itraconazole, and fluoroquinolone agents therefore, administration should be separated in time. Serum levels of didanosine are increased when -administered with tenofovir or ganciclovir, and are decreased by atazanavir, delavirdine, ritonavir, tipranavir, and methadone (Table 49-4). 

Drug-drug interactions involving fexofenadine have been reported which includes not only interactions with concomitant chugs, but also those with fruit juices. Concomitant use of itraconazole (303), verapamil (304), and ritonavir (305) increased the area under the curve of the plasma concentration (AUC) and peak plasma concentration (Cmax) of fexofenadine following oral administration, but did not affect the elimination half-life. Itraconazole and verapamil did not affect the renal clearance of fexofenadine, while the effect of ritonavir on the renal clearance was not examined. Considering the absence of the effect on the renal clearance, these interactions will include the inhibition of intestinal... 

MODAFINIL 1. ANTIBIOTICS-clarithromycin, telithromycin 2. ANTIFUNGALS-itraconazole, ketoconazole 3. ANTIVIRALS-indinavir, nelfinavir, ritonavir, saquinavir t plasma concentrations of modafinil, with risk of adverse effects Due to inhibition of CYP3A4, which has a partial role in the metabolism of modafinil Be aware. Warn patients to report dose-related adverse effects, e.g. headache, anxiety... 

IMATINIB 1. ANTIBIOTICS - clarithromycin, erythromycin 2. ANTIFUNGALS -fluconazole, itraconazole, ketoconazole voriconazole 3. ANTIVIRALS -efavirenz, ritonavir 4. GRAPEFRUIT JUICE 5. H2 RECEPTOR BLOCKERS - cimetidine t imatinib levels with t risk of toxicity (e.g. abdominal pain, constipation, dyspnoea) and of neurotoxicity (e.g. taste disturbances, dizziness, headache, paraesthesia, peripheral neuropathy) Due to inhibition of CYP3A4-mediated metabolism of imatinib Monitor for clinical efficacy and for the signs of toxicity listed, along with convulsions, confusion and signs of oedema (including pulmonary oedema). Monitor electrolytes and liver function, and for cardiotoxicity... 

The HIV protease inhibitor saquinavir has hmited and variable oral systemic availability and ritonavir, an inhibitor of CYP450 and P glycoprotein, is widely used to increase its systemic exposure. A small pilot study in three HIV-infected patients has suggested that oral itraconazole can have similar effects on the oral availability of saquinavir (109). Concomitant use of itraconazole 200 mg/day with a combination of saquinavir and two nucleoside reverse transcriptase inhibitors led to a 2.5-to 6.9-fold increase in the AUC of saquinavir, a 2.0- to 5.4-fold increase in peak plasma concentrations, and a 1.6-to 17-fold increase in trough plasma concentrations. The effect of itraconazole on saquinavir was comparable to that of ritonavir. 

Hoetelmans RM. Itraconazole as an alternative for ritonavir liquid formulation when combined with saquinavir. AIDS 2000 14(l) 89-90. 

Clinically important, potentially hazardous interactions with alcohol, aprepitant, clarithromycin, CNS depressants, delavirdine, digoxin, efavirenz, fluconazole, fluoxetine, fluvoxamine, grapefruit juice, indinavir, itraconazole, ivermectin, kava, ketoconazole, propoxyphene, ritonavir, saquinavir, St John s wort... 

Clinically important, potentially hazardous interactions with alprazolam, astemizole, carbamazepine, cisapride, clarithromycin, dexamethasone, diltiazem, docetaxel, ifosfamide, imatinib, irinotecan, itraconazole, ketoconazole, methylprednisolone, midazolam, nefazodone, oral contraceptives, paroxetine, phenytoin, pimozide, rifampin, ritonavir, terfenadine, tolbutamide, trabectedin, troleandomycin, vinblastine, vincristine, warfarin... 

Clinically important, potentially hazardous interactions with amantadine, anticholinergics, antidepressants, antimuscarinics, atazanavir, carbamazepine, clarithromycin, CYP2D6 inhibitors, CYP3A4 inducers, CYP3AF inhibitors, indinavir, itraconazole, ketoconazole, nefazodone, nelfinavir, phenobarbital, phenytoin, rifampicin, ritonavir, saquinivir, St John s wort, telithromycin... 

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