Exposure to efavirenz may increase with the use of the drug concomitantly with certain drugs (eg ritonavir) or foods (eg, grapefruit juice) that inhibit isoenzymes CYP3A4 or CYP2B6. Preparations based on the extract of Ginkgo Biloba, which induce these isozymes, can lead to a decrease in the concentration of efavirenz in the blood plasma.
Contraindicated the simultaneous use of efavirenz with terfenadine, astemizole, cisapride, midazolam, triazolam, pimozide, bepridil and ergot alkaloids (eg, ergotamine, dihydroergotamine, ergometrine and methylergometrin), as inhibition of their metabolism by efavirenz can cause serious life-threatening consequences (see " Contraindications ").
Interactions between efavirenz and HIV protease inhibitors, other antiretroviral drugs, in addition to HIV protease inhibitors, as well as between efavirenz and non-ARV drugs, are shown in Table 2 below.
An increase in the indicator value is indicated by the arrow "↑", a decrease in the value by the arrow "↓", if the indicator remains unchanged - by the arrow "↔"; if the drug was injected every 8 or 12 hours, this is designated as "k8h "or" k12h. "If necessary, 90% and 95% confidence intervals are shown in parentheses.Usually, studies were conducted on healthy volunteers, unless otherwise specified.
Drugs, divided by pharmacotherapeutic groups (dose) | Effect on the concentration of the drug in the serum. Average change in AUC, Cmax, Cmin (%) and confidence intervals, if applicablea (mechanism) | Recommendations regarding the possibility of simultaneous use with efavirenz |
ANTIMICROBIAL PREPARATIONS |
Antiretroviral medications |
HIV protease inhibitors |
Atazanavir / ritonavir / efavirenz (400 mg once a day / 100 mg once a day / 600 mg once a day, weights were taken during meals) | Atazanavir (after noon): AUC: ↔ (from ↓ 9 to ↑ 10) FROMmOh: ↑ 17% * (from ↑ 8 to ↑ 27) Cmin: ↓ 42% * (from ↓ 31 to ↓ 51) | Simultaneous use of efavirenz with atazanavir / ritonavir Mr.e is recommended. If simultaneous use of atazanavir with NNRTI is required, consideration should be given to increasing the dose of atazanavir to 400 mg and ritonavir to 200 mg, in combination with efavirenz, with careful clinical monitoring. |
Atazanavir / ritonavir / efavirenz (400 mg once a day / 200 mg once a day / 600 mg once a day, all preparations were taken during meals) | Atazanavir (after noon): AUC: ↔*/** (from ↓ 10 to ↑ 2 6) FROMmOh: ↔*/** (from ↓ 5 to ↑ 26) Cmin: ↑12%*/** (from ↓ 16 before ↑49) (induction of CYP3A4). * When compared with atazanavir 300 mg / ritonavir 100 mg 1 time per day in the evening without efavirenz. Such a decrease in Cmin Atazanavir can adversely affect the effectiveness of atazanavir ** based on a historical comparison. |
Darunavir / ritonavir / efavirenz (300 mg twice a day * / 100 mg twice a day / 600 mg once a day) * Below the recommended dose. Similar results are expected when applied at the recommended doses. | Darunavir: AUC: ↓ 13% Cmin: ↓31% Cmax: ↓15% (induction of CYP3A4) Efavirenz: AUC: ↑ 21% Cmin: ↑17% FROMmOh: ↑15% (inhibition of CYP3A4) | Simultaneous reception of efavirenz and darunavir / ritonavir (800 mg / 100 mg once a day) can lead to a decrease in Cmin darunavir. If efavirenz should be used simultaneously with darunavir / ritonavir, a combination of darunavir / ritonavir in the 600 mg / 100 mg regimen should be used 2 times a day. However, this combination should be administered with caution. See the instructions for the medical use of darunavir / ritonavir. See also information on ritonavir below. |
Fosamprenavir / ritonavir / efavirenz (700 mg twice a day / 100 mg twice a day / 600 mg once a day) | Clinically significant pharmacokinetic interaction was not revealed. | Correction of the dose of none of these medicines is required. See also information on ritonavir below. |
Fosamprenavir / nelfinavir / efavirenz | The interaction was not studied. | Correction of the dose of none of these medicines is required. |
Fosamprenavir / saquinavir / efavirenz | The interaction was not studied. | The use of this combination is not recommended, since a significant reduction in the exposure of both HIV protease inhibitors is expected. |
Indinavir / efavirenz (800 mg k8h / 200 mg once a day) | Indinavir: AUC: ↓ 31% (from ↓ 8 to ↓ 47) Cmin: ↓40% A similar decrease in indinavir exposure was observed in cases when indinavir (1000 mg k8h) was administered in combination with efavirenz (600 mg once a day). (induction of CYP3A4) Efavirenz: clinically significant pharmacokinetic interaction was not observed. | Although the clinical significance of reducing the concentration of indinavir is not established, the observed pharmacokinetic interaction should be taken into account when choosing a therapy regimen that includes both efavirenz and indinavir. Correction of the dose of efavirenz is not required if it is administered with indinavir or with indinavir / ritonavir. See also information on ritonavir below. |
Indinavir / ritonavir / efavirenz (800 mg twice a day / 100 mg twice a day / 600 mg once a day) | Indinavir: AUC: ↓ 25% (from ↓ 16 to ↓ 32)b Cmax: ↓17% (from ↓ 6 to ↓ 26)b Cmin: ↓50% (from ↓ 40 to ↓ 59)b Efavirenz: Clinically significant interaction was not observed. The geometric mean Cmin Indinavir (0.33 mg / L) when used in combination with ritonavir and efavirenz was greater than when applied in monotherapy at 800 mg k8h (Cmin 0.15 mg / l). In patients infected with HIV-1 (n = 6), the indices of pharmacokinetics of indinavir and efavirenz were usually comparable to those of uninfected volunteers |
Lopinavir / ritonavir in soft capsules or in oral solution / efavirenz | Significant decrease in exposure to lopinavir. | With simultaneous appointment with efavirenz should consider the increase in doses of lopinavir and ritonavir in soft capsules or in the solution for oral administration by 33% (4 capsules / ~ 6.5 ml 2 times a day instead of 3 capsules / 5 ml 2 times a day) . However, care should be taken because such a dose adjustment may not be sufficient for some patients. |
Lopinavir / ritonavir in tablets / efavirenz (400/100 mg twice a day / 600 mg once a day) (500/125 mg twice a day / 600 mg once a day) | Concentrations of lopinavir: ↓30-40% Concentrations of lopinavir are similar to those of lopinavir / ritonavir 400/100 mg twice daily without efavirenz. | The dose of lopinavir and ritonavir in tablets should be increased to 500/125 mg 2 times a day with simultaneous use with efavirenz 600 mg once a day. See also information on ritonavir below. |
Nelfinavir / efavirenz (750 mg k8h / 600 mg once daily) | Nelfinavir: AUC: ↑ 20% (from ↑ 8 to ↑ 34) FROMmOh: ↑21% (from ↑10 before ↑33) This combination is usually well tolerated. | Correction of the dose of none of these medicines is required. |
Ritonavir / efavirenz (500 mg twice a day / 600 mg once a day) | Ritonavir: AUC: in the morning: ↑ 18% (↑ 6 - ↑ 33) AUC in the evening: ↔ FROMmOh in the morning: ↑ 24% (↑ 12 - ↑ 38) FROMmOh in the evening: ↔ Cmin in the morning: ↑ 42% (↑ 9 - ↑ 86)b Cmin in the evening: ↑ 24% (↑ 3 - ↑ 50)b Efavirenz: AUC: ↑ 21% (↑ 10 - ↑ 34) FROMmOh: ↑14% (↑4 - ↑26) Cmin: ↑25% (↑7 - ↑46)b (inhibition of CYP-mediated oxidative metabolism) When taking efavirenz in combination with ritonavir 500 mg or 600 mg 2 times a day, the tolerance was low (for example, dizziness, nausea, paresthesia, increased activity of "hepatic" enzymes). Sufficient data on the tolerability of efavirenz in combination with ritonavir in low doses (100 mg 1 or 2 times a day) are absent. | In the appointment of efavirenz with ritonavir in low doses, the possibility of increasing the frequency of adverse effects associated with efavirenz due to possible pharmacodynamic interaction should be considered. |
Saquinavir / ritonavir / efavirenz | The interaction was not studied. | There are no data to develop recommendations for the dosing regimen. See also information on ritonavir above. The use of efavirenz in combination with saquinavir as the sole inhibitor of HIV protease is not recommended. |
CCR5 chemokine receptor antagonists |
Maraviroc / efavirenz (100 mg twice a day / 600 mg once a day) | Maraviroc: AUC12: ↓45% (↓38 - ↓51) FROMmOh: ↓51% (↓37 - ↓62) Concentrations of efavirenz were not measured, no interaction is expected. | See instructions for medical use of medications that include maraviroc. |
HIV integrase inhibitor |
Raltegravir / efavirenz (400 mg single dose / -) | Raltegravir: AUC: ↓ 36% FROM12: ↓21% FROMmOh: ↓36% (induction of the enzyme UDF-GT1A1) | Correction of doses of raltegravir is not required. |
Medicines from groups NOFROM and NNRTIs |
NRTI / efavirenz | Research interactions of efavirenz and drugs from the NRTI group were not performed, except for interactions with lamivudine, zidovudine, and tenofovir with dizoproxil fumarate. Clinically significant interactions are not anticipated, as the metabolism of NRTI drugs proceeds in ways other than those for efavirenz, and it is unlikely that they will compete for the same metabolic enzymes and elimination routes. | Correction of a dose of none of these medicines is required. |
NNRTI / efavirenz | The interaction was not studied. | Since the use of two NNRTIs does not provide an advantage in terms of efficacy and safety, simultaneous use of efavirenz and other NNRTI agents is not recommended. |
Medicines against hepatitis C virus |
Bocepreviir / efavirenz (800 mg three times a day / 600 mg once a day) | AUC: ↔ 19% * FROMmOh: ↔ 8% Cmin: ↓44% Efavirenz: AUC: ↔ 20% FROMmOh ↔ 11% Cmin: ↓12% (↓24% - ↑1%) (induction of CYP3A affects boceprevir) * 0-8 hours The lack of effect ("->) corresponds to a decrease in the average ratio by no more than 20% or an increase of no more than 25%. | The clinical significance of a decrease in the concentration of bocetrephir in blood plasma is not established. |
Telaprevir / efavirenz (1125 mg every 8 hours / 600 mg once daily) | Telaprevir (relative to 750 mg every 8 hours): AUC: ↓ 18% (↓ 8 - ↓ 27) FROMmOh: ↓14% (↓3 - ↓24) Cmin: ↓25% (↓14 - ↓34)% Efavirenz: AUC: ↓ 18% (↓ 10 - ↓ 26) FROMmOh: ↓24% (↓15 - ↓32) Cmin: ↓10% (↑1 - ↓19)% (induction of CYP3A4) | When combined use of telaprevir and efavirenz is recommended to increase the dose of telaprevir to 1125 mg every 8 hours. |
Symeprevir / efavirenz (150 mg once a day / 600 mg once a day) | Simeprevir: AUC: ↓ 71% (↓ 67 - ↓ 74) FROMmOh: ↓51% (↓46 - ↓56) Cmin: ↓91% (↓88 - ↓92) Efavirenz: AUC: ↔,FROMmOh: ↔, Cmin: ↔ (induction of CYP3A4) | The simultaneous administration of simeprevir with efavirenz results in a significant decrease in the concentration of the simeprevir in plasma due to the induction of CYP3A with efavirenz, which may lead to a loss of the therapeutic effect of simeprevir. Joint use of simeprevir and efavirenz is not recommended |
Antibiotics |
Azithromycin / efavirenz (600 mg as a single dose / 400 mg once daily) | Clinically significant pharmacokinetic interaction was not revealed. | Correction of a dose of none of these medicines is required. |
Clarithromycin / efavirenz (500 mg to 12 hours / 400 mg once daily) | Clarithromycin: AUC: ↓ 39% (↓ 30 - ↓ 46) FROMmOh: ↓26% (↓ 15 - ↓35) 14-Hydroxymetabolite of clarithromycin: AUC: ↑ 34% (↑ 18 - ↑ 53) FROMmOh: ↑49% (↑32 - ↑69) Efavirenz: AUC: ↔ FROMmOh: ↑11% (↑3 - ↑19) (induction of CYP3A4) Skin rash was observed in 46% of uninfected volunteers who simultaneously took efavirenz and clarithromycin. | The clinical significance of changes in the concentration of clarithromycin in the blood plasma is not established. Instead of clarithromycin, one should consider the possibility of using another antibiotic, for example, azithromycin. Correction of the dose of efavirenz is not required. |
Other antibiotics from the macrolide group (eg, erythromycin) / efavirenz | The interaction was not studied. | There are no data to develop recommendations for the dosing regimen. |
Anti-tuberculosis drugs |
Rifabutin / efavirenz (300 mg once a day / 600 mg once a day) | Rifabutin: AUC: ↓ 38% (↓ 28 - ↓ 47) FROMmOh: ↓32% (↓15 - ↓46) FROMmin: ↓45% (↓31 - ↓56) Efavirenz: AUC: ↔ FROMmOh: ↔ FROMmin: ↓12% (↓24 - ↑1) (induction of CYP3A4) | The daily dose of rifabutin should be increased by 50% if simultaneous use with efavirenz is planned. It should also consider the feasibility of doubling the dose of rifabutin when rifabutin is used 2 or 3 times a week in combination with efavirenz. |
Rifampicin / Efavirenz (600 mg once a day / 600 mg once a day) | Efavirenz: AUC: ↓ 26% (↓ 15 - ↓ 36) FROMmOh: ↓20% (↓11 - ↓28) FROMmin: ↓32% (↓15 - ↓46) (induction of CYP3A4 and CYP2B6) | If efavirenz is used concomitantly with rifampicin in patients with a body weight of 50 kg or more, the daily dose of efavirenz should be increased to 800 mg to provide an exposure similar to that of efavirenz in a daily dose of 600 mg without rifampicin. The clinical effect of such a dose adjustment has not yet been studied. When adjusting the dose, individual tolerance and virologic response should also be considered (see "Pharmacological properties", "Pharmacokinetics"). Correction of a dose of rifampicin is not required. |
Antifungal medicinal facilities |
Itraconazole / efavirenz (200 mg to 12 hours / 600 mg once daily) | Itraconazole: AUC: ↓ 39% (↓ 21 - ↓ 53) FROMmOh: ↓37% (↓20 - ↓51) FROMmin: ↓44% (↓27 - ↓58) (reduction of the concentrations of itraconazole due to the induction of CYP3A4) Hydroxyytraconazole: AUC: ↓ 37% (↓ 14 - ↓ 55) FROMmOh: ↓35% (↓12 - ↓52) FROMmin: ↓43% (↓18 - ↓60) Efavirenz: there were no clinically significant changes. | Since it is impossible to make recommendations on the dosage regimen of itraconazole, the possibility of using alternative antifungal medicines should be considered. |
Posaconazole / efavirenz - / 400 mg once a day | Posaconazole: AUC: ↓ 50% FROMmOh: ↓45% (induction of UDP-glucuronation) | The simultaneous use of posaconazole and efavirenz should be avoided, unless the expected benefit to the patient does not exceed the possible risk. |
Voriconazole / efavirenz (200 mg twice a day / 400 mg once a day) | Voriconazole: AUC: ↓ 77% FROMmOh: ↓61% Efavirenz: AUC: ↑ 44% FROMmOh: ↑38% | With simultaneous use of efavirenz with voriconazole, the maintenance dose of voriconazole should be increased to 400 mg twice a day, and the dose of efavirenz is reduced by 50%, i.e. up to 300 mg once a day. If the use of voriconazole is discontinued, the dose of efavirenz should be restored to the initial dose. It should be borne in mind that tablets with a low dose of efavirenz in the Russian Federation are not registered. |
Voriconazole / efavirenz (400 mg twice a day / 300 mg once a day) | Voriconazole: AUC: ↓ 7% (↓ 23 - ↑ 13) * FROMmOh: ↑23% (↓1 - ↑53)* Efavirenz: AUC: ↑ 17% (↑ 6 - ↑ 29) ** FROMmOh: ↔** * Compared with 200 mg 2 times a day when used in monotherapy ** Compared with 600 mg once a day when used in monotherapy (competitive inhibition of oxidative metabolism) |
Fluconazole / efavirenz (200 mg once a day / 400 mg once a day) | Clinically significant interaction was not revealed. | Correction of a dose of none of these medicines is required. |
Ketoconazole and other antifungal agents - imidazole derivatives | The interaction was not studied. | There are no data that allow to develop recommendations on the dosage regimen. |
ANTI-MALIGNANT MEDICINES |
Atovahon / proguanil / efavirenz (250 mg / 100 mg single dose / 600 mg once daily) | Atovahon: AUC: ↓ 75% (from ↓ 62 to ↓ 84) FROMmOh: ↓ 44% (from ↓ 20 to ↓ 61) Proguanil: AUC: ↓ 43% (from ↓ 7 to ↓ 65) FROMmOh: ↔ | If possible, simultaneous use of atovahona / proguanil with efavirenz should be avoided. |
Artemether / lumefantrine / efavirenz (20 mg / 120 mg, 6 doses of 4 tablets for 3 days / 600 mg once a day) | Artemether: AUC: ↓ 51% FROMmOh: ↓21% Dihydroartemisinin: AUC: ↓ 46% FROMmOh: ↓38% Lumefantrine: AUC: ↓ 21% FROMmOh: ↔ Efavirenz AUC: ↓ 17% FROMmOh: ↔ (induction of CYP3A4) | It is possible to reduce the antimalarial effect due to a decrease in the concentration of artemether and lumefantrine with simultaneous use with efavirenz. Caution should be exercised while using efavirenz with artemether and lumefantrine. |
ANTACIDE MEDICINES |
Antacids containing aluminum hydroxide - magnesium hydroxide - simethicone / efavirenz (30 mL single dose / 400 mg single dose) Famotidine / efavirenz (40 mg single dose / 400 mg single dose) | As antacids containing aluminum hydroxide or magnesium hydroxide, and famotidine do not adversely affect the absorption of efavirenz. | It is unlikely that with the use of efavirenz with drugs that affect the pH of gastric contents, the absorption of efavirenz will change. |
ANKSIOLITHICS |
Lorazepam / efavirenz (2 mg single dose / 600 mg once daily) | Lorazepam: AUC: ↑ 7% (↑ 1 - ↑ 14) FROMmOh: ↑16% (↑2 - ↑ 32) These changes are not considered clinically significant. | Correction of a dose of none of these medicines is required. |
ANTICOAGULANTS |
Warfarin / efavirenz Acenocoumarol / efavirenz | The interaction was not studied. Perhaps both an increase and a decrease in the concentration of warfarin / acenocoumarol in the blood plasma under the influence of efavirenz. | It may be necessary to adjust the dose of warfarin / acenocoumarol. |
ANTI-SURGERY MEDICINES |
Carbamazepine / efavirenz (400 mg once a day / 600 mg once a day) | Carbamazepine: AUC: ↓ 27% (↓ 20 - ↓ 33) FROMmOh: ↓20% (↓5 - ↓24) FROMmin: ↓35% (↓24 - ↓44) Efavirenz: AUC: ↓ 36% (↓ 32 - ↓ 40) FROMmOh: ↓21% (↓15 - ↓26) FROMmin ↓47% (↓41 -↓53) (decrease in carbamazepine concentrations due to induction of CYP3A4, decrease in efavirenz concentrations due to induction of CYP3A4 and CYP2B6). Equilibriumth values of AUC, CmOh and Cmin the active metabolite of carbamazepine epoxide does not change. Interaction with the simultaneous use of higher doses of efavirenz or carbamazepine has not been studied. | There is no data on the basis of which it is possible to develop recommendations on the dosage regimen. Consider using another anticonvulsant drug. It is recommended to carry out periodic monitoring of the concentration of carbamazepine in the blood plasma. |
Phenytoin, phenobarbital and other anticonvulsant drugs, which are substrates of the CYP450 isoenzymes | The interaction was not studied. Perhaps both a reduction and an increase in the concentrations of phenytoin, phenobarbital and other anticonvulsant drugs, which are substrates of CYP450 isoenzymes (when used simultaneously with efavirenz). | If efavirenz It is used simultaneously with anticonvulsants, which are substrates of CYP450 isoenzymes, it is necessary to carry out periodic monitoring of concentrations anticonvulsants in the blood. |
Valproic acid / efavirenz (250 mg twice a day / 600 mg once a day) | There was no clinically significant effect on the pharmacokinetics of efavirenz. Limited data show that there is no clinically significant effect on the pharmacokinetics of valproic acid. | Correction of the dose of efavirenz is not required. Patients should be monitored to monitor seizures. |
Vigabatrin / efavirenz Gabapentin / efavirenz | The interaction was not studied. Clinically significant interactions are unlikely, since vigabatrin and gabapentin are excreted exclusively by the kidneys in an unchanged form and are unlikely to compete with the metabolizing enzymes and the ways of excretion of efavirenz. | Correction of the dose of none of the these medicines are not required. |
ANTI-DEPRESSANTS |
Selective serotonin reuptake inhibitors |
Sertraline / efavirenz (50 mg once a day / 600 mg once a day) | Sertraline: AUC: ↓ 39% (↓ 27 - ↓ 50) FROMmOh: ↓29% (↓15 - ↓40) FROMmin: ↓46% (↓31 - ↓58) Efavirenz: AUC: ↔ FROMmOh: ↑11% (↑6 - ↑16) FROMmin: ↔ (induction of CYP3A4). | An increase in the dose of sertraline should be performed taking into account the clinical response. Correction of the dose of efavirenz is not required. |
Paroxetine / efavirenz (20 mg once a day / 600 mg once a day) | Clinically significant pharmacokinetic interaction was not revealed. | Correction of a dose of none of these medicines is required. |
Fluoxetine / efavirenz | The interaction was not studied. Since fluoxetine has the same metabolic profile as paroxetine, i.e. it is a potent inhibitor of CYP2D6, one can expect that fluoxetine also will not interact with efavirenz. | Correction of a dose of none of these medicines is required. |
Selective inhibitors of re-uptake of catecholamines (norepinephrine, dopamine) |
Bupropion / efavirenz (150 mg single dose (prolonged action) / 600 mg once daily) | Bupropion: AUC: ↓ 55% (↓ 48 - ↓ 62) FROMmOh: ↓34% (↓21 - ↓47) Hydroxybupropion: AUC: ↔ FROMmOh: ↑50% (↑20 - ↑80) (induction of CYP2B6) | An increase in the dose of bupropion should be made taking into account the clinical response, but the dose should not exceed the maximum recommended dose. Correction of the dose of efavirenz is not required. |
BLOCKERS H1-GISTAIN RECEPTORS |
Cetirizine / efavirenz (10 mg single dose / 600 mg once daily) | Cetirizine: AUC: ↔ FROMmOh: ↓24% (↓18% - ↓30%) These changes are not considered clinically significant. Efavirenz: Clinically significant interaction was not revealed. | Correction of a dose of none of these medicines is required. |
CARDIOVASCULAR PREPARATIONS |
Blocks of "slow" calcium channels |
Diltiazem / efavirenz (240 mg once a day / 600 mg once a day) | Diltiazem: AUC: ↓ 69% (↓ 55 - ↓ 79) FROMmOh: ↓60% (↓50 - ↓68) FROMmin: ↓63% (↓44 - ↓75) Deacetylldithiazine: AUC: ↓ 75% (↓ 59 - ↓ 84) FROMmOh: ↓64% (↓57 - ↓69) FROMmin: ↓62% (↓44 - ↓75) N-monodomethyl-dithiothiazem: AUC: ↓ 37% (↓ 17 - ↓ 52) FROMmOh: ↓28% (↓7 - ↓44) FROMmin: ↓37% (↓17 - ↓52) Efavirenz: AUC: ↑11% (↑5 - ↑18) FROMmOh: ↑ 16% (↑6 - ↑26) FROMmin: ↑13% (↑1 - ↑26) (induction of CYP3A4) The increase in pharmacokinetic parameters of efavirenz was not regarded as clinically significant. | The question of the need for correcting the dose of diltiazem is solved in view of the clinical response (see the instructions for the medical use of diltiazem). Correction of the dose of efavirenz is not required. |
Verapamil, felodipine, nifedipine and nicardipine | The interaction was not studied. If efavirenz is used simultaneously with any drug from the group of "slow" calcium channel blockers, which are substrates of the CYP3A4 isoenzyme, it is possible to reduce the concentration of this torus block in the blood plasma. | The question of the need for correction of doses of blockers of "slow" calcium channels is solved taking into account the clinical response (see instructions for the medical use of blockers of "slow" calcium channels). |
HYPOLIDEMIC DRUGS |
Inhibitors of HMG-CoA reductase |
Atorvastatin / efavirenz (10 mg once a day / 600 mg once a day) | Atorvastatin: AUC: ↓ 43% (↓ 34 - ↓ 50) FROMmOh: ↓12% (↓1 - ↓26) 2-Hydroxy-atvastatin: AUC: ↓ 35% (↓ 13 - ↓ 40) FROMmOh: ↓13% (↓0 - ↓23) 4-hydroxy-aortastatin: AUC: ↓ 4% (↓ 0 - ↓ 31) FROMmOh: ↓47% (↓9 - ↓51) Total activity of HMG-CoA reductase inhibitors: AUC: ↓ 34% (↓ 21 - ↓ 41) FROMmOh: ↓20% (↓2 - ↓26) | Periodic monitoring of cholesterol concentration in the blood should be performed. It may be necessary to adjust the dose of atorvastatin (see the instructions for the medical use of atorvastatin). Correction of the dose of efavirenz is not required. |
Pravastatin / efavirenz (40 mg once a day / 600 mg once a day) | Pravastatin: AUC: ↓ 40% (↓ 26 - ↓ 57) FROMmOh: ↓18% (↓59 - ↑12) | It should beimplement periodic monitoring of cholesterol concentration in the blood. It may be necessary to correct the dose of pravastatin (see instructions for the medical use of pravastatin). Correction of the dose of efavirenz is not required. |
Simvastatin / efavirenz (40 mg once a day / 600 mg once a day) | Simvastatin: AUC: ↓ 69% (↓ 62 - ↓ 73) FROMmOh: ↓76% (↓63 - ↓79) Simvastatin acid: AUC: ↓ 58% (↓ 39 - ↓68) FROMmOh: ↓51% (↓32 - ↓58) Total activity of HMG-CoA reductase inhibitors: AUC: ↓ 60% (↓ 52 - ↓ 68) FROMmOh: ↓62% (↓55 - ↓78) (induction of CYP3A4) With simultaneous use of efavirenz with atorvastatin, pravastatin or simvastatin, the values of AUC and CmOh Efavirenz does not change. | Periodic monitoring of cholesterol concentration in the blood should be performed. It may be required correction of the dose of simvastatin (see the instructions for the medical use of simvastatin). Correction of the dose of efavirenz is not required. |
Rosuvastatin / efavirenz | The interaction was not studied. Rosuvastatin is excreted mainly unchanged through the gastrointestinal tract with bile, so interaction with efavirenz is not expected. | Correction of a dose of none of these medicines is required. |
HORMONAL CONTRACEPTES |
For oral administration: Ethinylestradiol + norgestimate / efavirenz (0.035 mg + 0.25 mg once a day / 600 mg once daily) | Ethinyl estradiol: AUC: ↔ FROMmOh: ↔ Cmin: ↓8% (↑14 - ↑25) Norelgestromine (active metabolite): AUC: ↓ 64% (↓ 62 - ↓ 67) FROMmOh: ↓46% (↓39 - ↓52) Cmin: ↓82% (↓79 - ↓85) Levonorgestrel (active metabolite): AUC: ↓ 83% (↓ 79 - ↓ 87) FROMmOh: ↓80% (↓77 - ↓83) Cmin: ↓86% (↓80 - ↓90) (induction of metabolism) Efavirenz: clinically significant interaction is not revealed. The clinical significance of these effects is not known. | In addition to hormonal contraceptives, a reliable method of barrier contraception should be used (see the section on "Application during pregnancy and during breastfeeding"). |
Prolonged action for intramuscular injection: Depo-medroxyprogesterone acetate (DMPA) / efavirenz (150 mg of DMPA IM once) | Within 3 months of the study, there were no significant differences in the pharmacokinetic parameters medroxyprogesterone between volunteers receiving ARVT, efavirenz, and volunteers who did not receive ARVT. In the second study, similar results were obtained, although the concentrations of medroxyprogesterone in the plasma differed to a greater extent. In both studies, plasma progesterone concentrations in volunteers who received efavirenz + depot-medroxyprogesterone acetate, remained low, which corresponded to suppressionMr.of ovulation. | In addition to hormonal contraceptives, a reliable method of barrier contraception should be used (see the section on "Application during pregnancy and during breastfeeding"). |
Implant: Etonogestrel / efavirenz | The interaction was not studied. You can expect a decrease in the exposure of etonogestrel (induction CYP3A4). During the post-registration period of observation, separate reports were received on the lack of contraceptive effect in the use of etonogestrel in patients taking efavirenz. | In addition to hormonal contraceptives, a reliable method of barrier contraception should be used (see the section on "Application during pregnancy and during breastfeeding"). |
IMMUNODEPRESSANTS |
Immunosuppressants, which are metabolized by the isoenzyme CYP3A4 (for example, ciclosporin, tacrolimus, sirolimus) / efavirenz | The interaction was not studied. You can expect a decrease in the exposure of the immunosuppressant (induction of CYP3A4). It is unlikely that these immunosuppressants will affect the exposure of efavirenz. | You may need to adjust the dose of immunosuppressant. It is recommended that the concentration of the immunosuppressant in the blood be carefully monitored for at least 2 weeks (until steady-state concentrations are established) from the start of efavirenz therapy or from the moment of its withdrawal. |
OPIOIDS |
Methadone / efavirenz (stable maintenance dose, 35-100 mg once a day / 600 mg once a day) | Methadone: AUC: ↓ 52% (↓ 33 - ↓ 66) FROMmOh: ↓45% (↓25 - ↓59) (induction of CYP3A4) In a study involving HIV-infected patients who injected narcotics intravenously, it was found that simultaneous use of efavirenz and methadone led to a decrease in the concentration of methadone in the blood plasma and to the appearance of symptoms of opiate withdrawal. To reduce the severity of withdrawal symptoms, the methadone dose was increased by an average of 22%. | Patients should be monitored for the timely detection of withdrawal symptoms. If necessary, the dose of methadone should be increased to reduce the severity of withdrawal symptoms. |
Buprenorphine / naloxone / efavirenz | Buprenorphine: AUC: ↓ 50% Norbuprenorphine: AUC: ↓ 71% Efavirenz: Clinically significant pharmacokinetic interaction was not revealed. | Despite a decrease in buprenorphine exposure, no symptoms of withdrawal were observed in patients. No dosage adjustment is required for any of the medicines with simultaneous administration of buprenorphine and efavirenz. |
UDF is uridine diphosphate.
Interaction studies were conducted only in adults.