Drug Interaction Report
10 potential interactions and/or warnings found for the following 2 drugs:
- felodipine
- emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Interactions between your drugs
felodipine ritonavir
Applies to: felodipine, emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Consumer information for this interaction is not currently available.
MONITOR: Coadministration with potent CYP450 3A4 inhibitors may significantly increase the plasma concentrations of felodipine. The proposed mechanism is decreased first-pass metabolism and hepatic clearance of felodipine due to inhibition of CYP450 3A4 activity. In 9 healthy volunteers, administration of a single 5 mg oral dose of felodipine following pretreatment with itraconazole 200 mg once daily for 4 days resulted in average increases of nearly 8-fold in felodipine peak plasma concentration (Cmax), 6-fold in systemic exposure (AUC), and 2-fold in elimination half-life compared to administration with placebo. The decreases in blood pressure and increases in heart rate were also significantly greater with itraconazole. There have also been case reports of leg and ankle edema in patients treated with various itraconazole-dihydropyridine calcium channel blocker (CCB) combinations. In a population-based retrospective cohort study of older adults (average age of 76 years), administration of clarithromycin during treatment with a CCB (amlodipine, felodipine, nifedipine, diltiazem, or verapamil), increased patients' odds of being hospitalized for acute kidney injury. Secondary outcomes indicated an increased risk of hospitalisation due to hypotension and an increased risk of all-cause mortality when compared to azithromycin.
MANAGEMENT: Caution is advised if potent CYP450 3A4 inhibitors must be used concomitantly with felodipine. If concomitant use is required, dosage adjustments as well as clinical and laboratory monitoring may be appropriate whenever a potent CYP450 3A4 inhibitor is added to or withdrawn from therapy. Some authorities recommend avoiding coadministration of potent CYP450 3A4 inhibitors with felodipine (CA, UK). Patients should be advised to seek medical attention if they experience edema or swelling of the lower extremities; sudden, unexplained weight gain; difficulty breathing; chest pain or tightness; or hypotension as indicated by dizziness, fainting, or orthostasis.
felodipine lopinavir
Applies to: felodipine, emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Using lopinavir together with felodipine can increase the risk of an irregular heart rhythm that may be serious. You may need a dose adjustment or special tests to safely use both medications. You should seek immediate medical attention if you develop sudden dizziness, lightheadedness, fainting, or irregular heartbeat during treatment with these drugs, whether together or alone. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
ritonavir tenofovir
Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil, emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Ritonavir may increase the blood levels and effects of tenofovir. This can increase the risk of side effects including serious ones like kidney or liver damage and a condition known as lactic acidosis, which is a buildup of lactic acid in the blood. You should seek immediate medical attention if you develop symptoms of these conditions. Symptoms of kidney damage may include swelling, weight gain, shortness of breath, drowsiness, confusion, mood changes, increased thirst, loss of appetite, nausea, vomiting, pain in your lower back, and urinating more or less than usual or not at all. Symptoms of liver damage may include fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, and/or yellowing of the skin or eyes. Symptoms of lactic acidosis may include fatigue, unusual muscle pain, difficulty breathing, stomach pain, nausea, vomiting, lightheadedness, dizziness, and a fast or irregular heartbeat. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
lopinavir tenofovir
Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil, emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Lopinavir may increase the blood levels and effects of tenofovir. This can increase the risk of side effects including serious ones like kidney or liver damage and a condition known as lactic acidosis, which is a buildup of lactic acid in the blood. You should seek immediate medical attention if you develop symptoms of these conditions. Symptoms of kidney damage may include swelling, weight gain, shortness of breath, drowsiness, confusion, mood changes, increased thirst, loss of appetite, nausea, vomiting, pain in your lower back, and urinating more or less than usual or not at all. Symptoms of liver damage may include fever, chills, joint pain or swelling, unusual bleeding or bruising, skin rash, itching, loss of appetite, fatigue, nausea, vomiting, dark colored urine, and/or yellowing of the skin or eyes. Symptoms of lactic acidosis may include fatigue, unusual muscle pain, difficulty breathing, stomach pain, nausea, vomiting, lightheadedness, dizziness, and a fast or irregular heartbeat. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Drug and food interactions
felodipine food
Applies to: felodipine
You should avoid or limit the consumption of grapefruit and grapefruit juice if you are receiving treatment with felodipine. Grapefruit juice can significantly increase the blood levels and effects of medications like felodipine. You may be more likely to experience side effects such as headache, low blood pressure, irregular heartbeat, swelling, and fluid retention. Talk to your doctor or pharmacist if you have any questions or concerns. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
ritonavir food
Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Ritonavir should be taken with food to lessen gastrointestinal side effects. It is important that you take this medication exactly as prescribed by your doctor. Do not change your treatment or stop treatment without first talking to your doctor.
lopinavir food
Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Food may affect the absorption of lopinavir-ritonavir (brand name Kaletra) depending on whether you are taking the oral solution or the tablet. The oral solution should be taken with food to enhance absorption and help it work better. The tablet formulation can be take with or without food. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
felodipine food
Applies to: felodipine
Felodipine and ethanol (alcohol) may have additive effects in lowering your blood pressure. You may experience headache, dizziness, lightheadedness, fainting, and/or changes in pulse or heart rate. These side effects are most likely to be seen at the beginning of treatment, following a dose increase, or when treatment is restarted after an interruption. Let your doctor know if you develop these symptoms and they do not go away after a few days or they become troublesome. Avoid driving or operating hazardous machinery until you know how the medications affect you, and use caution when getting up from a sitting or lying position. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
felodipine food
Applies to: felodipine
Using felodipine together with multivitamin with minerals can decrease the effects of felodipine. Talk with your doctor before using felodipine and multivitamin with minerals together. You may need a dose adjustment or need your blood pressure checked more often if you take both medications. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
tenofovir food
Applies to: emtricitabine / lopinavir / ritonavir / tenofovir disoproxil
Information for this minor interaction is available on the professional version.
Therapeutic duplication warnings
No duplication warnings were found for your selected drugs.
Therapeutic duplication warnings are only returned when drugs within the same group exceed the recommended therapeutic duplication maximum.
Drug Interaction Classification
| Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit. | |
| Moderately clinically significant. Usually avoid combinations; use it only under special circumstances. | |
| Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan. | |
| No interaction information available. |
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