ARTEMETHER Drug Interactions: What You Need to Know

INTERACTIONS CYP3A4 Inducers: Potential for loss of antimalarial efficacy. ( 4 , 5.3 , 7.1 , 12.3 ) CYP3A4 Inhibitors: Use cautiously due to potential for QT prolongation. ( 5.3 , 7.2 , 12.3 ) Antiretrovirals: Use cautiously due to potential for QT prolongation, loss of antiviral efficacy, or loss of antimalarial efficacy of Coartem Tablets. ( 5.3 , 7.3 , 12.3 ) Mefloquine: If used immediately before treatment, monitor for decreased efficacy of Coartem Tablets and encourage food consumption. ( 2.1 , 7.4 , 12.3 )

Hormonal

Contraceptives: Effectiveness may be reduced; use an additional method of birth control. ( 5.3 , 7.5 , 12.3 ) CYP2D6 Substrates: Monitor for adverse reactions and potential QT prolongation. ( 5.1 , 5.4 , 7.6 )

7.1 Rifampin Oral administration of rifampin, a strong CYP3A4 inducer, with Coartem Tablets resulted in significant decreases in exposure to artemether, DHA (metabolite of artemether), and lumefantrine by 89%, 85%, and 68%, respectively, when compared to exposure values after Coartem Tablets alone. Concomitant use of strong inducers of CYP3A4 such as rifampin, carbamazepine, phenytoin, and St. John’s wort is contraindicated with Coartem Tablets <span class="opacity-50 text-xs">[see Contraindications (4) and Clinical Pharmacology (12.3)]</span> .

7.2 Ketoconazole Concurrent oral administration of ketoconazole, a potent CYP3A4 inhibitor, with a single dose of Coartem Tablets resulted in a moderate increase in exposure to artemether, DHA, and lumefantrine in a study of 15 healthy subjects. No dose adjustment of Coartem Tablets is necessary when administered with ketoconazole or other potent CYP3A4 inhibitors. However, due to the potential for increased concentrations of lumefantrine which could lead to QT prolongation, Coartem Tablets should be used cautiously with drugs that inhibit CYP3A4 <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1, 5.3) and Clinical Pharmacology (12.3)]</span> .

7.3 Antiretroviral Drugs Both artemether and lumefantrine are metabolized by CYP3A4. Antiretroviral drugs, such as protease inhibitors and non-nucleoside reverse transcriptase inhibitors, are known to have variable patterns of inhibition, induction or competition for CYP3A4. Therefore, the effects of antiretroviral drugs on the exposure to artemether, DHA, and lumefantrine are also variable <span class="opacity-50 text-xs">[see Clinical Pharmacology (12.3)]</span> .

Coartem

Tablets should be used cautiously in patients on antiretroviral drugs because decreased artemether, DHA, and/or lumefantrine concentrations may result in a decrease of antimalarial efficacy of Coartem Tablets, and increased lumefantrine concentrations may cause QT prolongation [see Warnings and Precautions (5.3)] .

7.4 Prior Use of Mefloquine Administration of 3 doses of mefloquine followed 12 hours later by a 6-dose regimen of Coartem Tablets in 14 healthy volunteers demonstrated no effect of mefloquine on plasma concentrations of artemether or the artemether/DHA ratio. However, exposure to lumefantrine was reduced, possibly due to lower absorption secondary to a mefloquine-induced decrease in bile production. Patients should be monitored for decreased efficacy and food consumption should be encouraged with administration of Coartem Tablets <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]</span> .

7.5 Hormonal Contraceptives In vitro , the metabolism of ethinyl estradiol and levonorgestrel was not induced by artemether, DHA, or lumefantrine. However, artemether has been reported to weakly induce, in humans, the activity of CYP2C19, CYP2B6, and CYP3A4. Therefore, Coartem Tablets may potentially reduce the effectiveness of hormonal contraceptives. Patients using hormonal contraception should be advised to use an alternative non-hormonal contraceptive method or add a barrier method of contraception during treatment with Coartem <span class="opacity-50 text-xs">[see Warnings and Precautions (5.3), Use in Specific Populations (8.3) and Clinical Pharmacology (12.3)]</span> .

7.6 CYP2D6 Substrates Lumefantrine inhibits CYP2D6 in vitro . Administration of Coartem Tablets with drugs that are metabolized by CYP2D6 may significantly increase plasma concentrations of the coadministered drug and increase the risk of adverse effects. Many of the drugs metabolized by CYP2D6 can prolong the QT interval and should not be administered with Coartem Tablets due to the potential additive effect on the QT interval (e.g., flecainide, imipramine, amitriptyline, clomipramine) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1, 5.4) and Clinical Pharmacology (12.3)]</span> .

7.7 Sequential Use of Quinine A single dose of intravenous quinine (10 mg/kg bodyweight) concurrent with the final dose of a 6-dose regimen of Coartem Tablets demonstrated no effect of intravenous quinine on the systemic exposure of DHA or lumefantrine. Quinine exposure was also not altered. Exposure to artemether was decreased. This decrease in artemether exposure is not thought to be clinically significant. However, quinine and other drugs that prolong the QT interval should be used cautiously following treatment with Coartem Tablets due to the long elimination half-life of lumefantrine and the potential for additive QT effects; ECG monitoring is advised if use of drugs that prolong the QT interval is medically required <span class="opacity-50 text-xs">[see Warnings and Precautions (5.2) and Clinical Pharmacology (12.3)]</span> .

7.8 Interaction With Drugs That are Known to Prolong the QT Interval Coartem Tablets are to be used with caution when coadministered with drugs that may cause prolonged QT interval such as antiarrhythmics of Classes IA and III, neuroleptics and antidepressant agents, certain antibiotics including some agents of the following classes: macrolides, fluoroquinolones, imidazole, and triazole antifungal agents <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1, 5.2)]</span> .

Hypersensitivity Known hypersensitivity to artemether, lumefantrine, or to any of the excipients of Coartem Tablets [see Adverse Reactions (6.2)] . Strong CYP3A4 Inducers Coadministration of strong inducers of CYP3A4 such as rifampin, carbamazepine, phenytoin, and St. John’s wort with Coartem Tablets can result in decreased concentrations of artemether and/or lumefantrine and loss of antimalarial efficacy [see Warnings and Precautions (5.3), Drug Interactions (7.1), and Clinical Pharmacology (12.3)] . Known hypersensitivity to artemether, lumefantrine, or to any of the excipients. ( 4 ) Coadministration of strong inducers of CYP3A4 such as rifampin, carbamazepine, phenytoin, and St. John’s wort with Coartem Tablets. ( 4 , 7.1 , 12.3 )

AND PRECAUTIONS Avoid use in patients with known QT prolongation, those with hypokalemia or hypomagnesemia, and those taking other drugs that prolong the QT interval. ( 5.1 , 12.6 ) Halofantrine and Coartem Tablets should not be administered within one month of each other due to potential additive effects on the QT interval. ( 5.1 , 5.2 , 12.3 ) Antimalarials should not be given concomitantly, unless there is no other treatment option, due to limited safety data. ( 5.2 ) QT prolonging drugs, including quinine and quinidine, should be used cautiously following Coartem Tablets. ( 5.1 , 5.2 , 7.7 , 12.3 ) Substrates, inhibitors, or inducers of CYP3A4, including antiretroviral medications, should be used cautiously with Coartem Tablets, due to a potential loss of efficacy of the concomitant drug or additive QT prolongation. ( 5.3 , 7.2 , 7.3 )

5.1 Prolongation of the QT Interval Some antimalarials (e.g., halofantrine, quinine, quinidine) including Coartem Tablets have been associated with prolongation of the QT interval on the electrocardiogram (ECG).

Coartem

Tablets should be avoided in patients: With congenital prolongation of the QT interval (e.g., long QT syndrome) or any other clinical condition known to prolong the QTc interval such as patients with a history of symptomatic cardiac arrhythmias, with clinically relevant bradycardia or with severe cardiac disease. With a family history of congenital prolongation of the QT interval or sudden death. With known disturbances of electrolyte balance, e.g., hypokalemia or hypomagnesemia. Receiving other medications that prolong the QT interval, such as Class IA (quinidine, procainamide, disopyramide), or Class III (amiodarone, sotalol) antiarrhythmic agents; antipsychotics (pimozide, ziprasidone); antidepressants; certain antibiotics (macrolide antibiotics, fluoroquinolone antibiotics, imidazole, and triazole antifungal agents) [see Clinical Pharmacology (12.6)] . Receiving medications that are metabolized by the cytochrome enzyme CYP2D6, which also have cardiac effects (e.g., flecainide, imipramine, amitriptyline, clomipramine) [see Warnings and Precautions (5.4), Drug Interactions (7.6), and Clinical Pharmacology (12.3)] .

5.2 Use of QT Prolonging Drugs and Other Antimalarials Halofantrine and Coartem Tablets should not be administered within 1 month of each other due to the long elimination half-life of lumefantrine (3 to 6 days) and potential additive effects on the QT interval <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1) and Clinical Pharmacology (12.3)]</span> . Antimalarials should not be given concomitantly with Coartem Tablets, unless there is no other treatment option, due to limited safety data. Drugs that prolong the QT interval, including antimalarials such as quinine and quinidine, should be used cautiously following Coartem Tablets, due to the long elimination half-life of lumefantrine (3 to 6 days) and the potential for additive effects on the QT interval; ECG monitoring is advised if use of drugs that prolong the QT interval is medically required <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1), Drug Interactions (7.7), and Clinical Pharmacology (12.3)]</span> . If mefloquine is administered immediately prior to Coartem Tablets, there may be a decreased exposure to lumefantrine, possibly due to a mefloquine-induced decrease in bile production. Therefore, patients should be monitored for decreased efficacy and food consumption should be encouraged while taking Coartem Tablets <span class="opacity-50 text-xs">[see Dosage and Administration (2.1), Drug Interactions (7.4), and Clinical Pharmacology (12.3)]</span> .

5.3 Drug Interactions With CYP3A4 When Coartem Tablets are coadministered with substrates of CYP3A4, it may result in decreased concentrations of the substrate and potential loss of substrate efficacy.

When Coartem

Tablets are coadministered with an inhibitor of CYP3A4, including grapefruit juice, it may result in increased concentrations of artemether and/or lumefantrine and potentiate QT prolongation.

When Coartem

Tablets are coadministered with inducers of CYP3A4, it may result in decreased concentrations of artemether and/or lumefantrine and loss of antimalarial efficacy [see Contraindications (4) and Drug Interactions (7)] . Drugs that have a mixed effect on CYP3A4, especially antiretroviral drugs such as HIV protease inhibitors and non-nucleoside reverse transcriptase inhibitors, and those that have an effect on the QT interval should be used with caution in patients taking Coartem Tablets [see Drug Interactions (7.3, 7.7)] .

Coartem

Tablets may reduce the effectiveness of hormonal contraceptives. Therefore, patients using hormonal contraceptives should be advised to use an alternative non-hormonal contraceptive method or add a barrier method of contraception during treatment with Coartem [see Drug Interactions (7.5)] .

5.4 Drug Interactions With CYP2D6 Administration of Coartem Tablets with drugs that are metabolized by CYP2D6 may significantly increase plasma concentrations of the coadministered drug and increase the risk of adverse effects. Many of the drugs metabolized by CYP2D6 can prolong the QT interval and should not be administered with Coartem Tablets due to the potential additive effect on the QT interval (e.g., flecainide, imipramine, amitriptyline, clomipramine) <span class="opacity-50 text-xs">[see Warnings and Precautions (5.1), Drug Interactions (7.6), and Clinical Pharmacology (12.3)]</span> .

5.5 Recrudescence Food enhances absorption of artemether and lumefantrine following administration of Coartem Tablets. Patients who remain averse to food during treatment should be closely monitored as the risk of recrudescence may be greater <span class="opacity-50 text-xs">[see Dosage and Administration (2.1)]</span> . In the event of recrudescent P. falciparum infection after treatment with Coartem Tablets, patients should be treated with a different antimalarial drug.

5.6 Hepatic and Renal Impairment Coartem Tablets have not been studied for efficacy and safety in patients with severe hepatic and/or renal impairment <span class="opacity-50 text-xs">[see Dosage and Administration (2.4)]</span> .

5.7 Plasmodium vivax Infection Coartem Tablets have been shown in limited data (43 patients) to be effective in treating the erythrocytic stage of P. vivax infection. However, relapsing malaria caused by P. vivax requires additional treatment with other antimalarial agents to achieve radical cure i.e., eradicate any hypnozoites forms that may remain dormant in the liver.