| 1 |
Tranexamic acid |
Hormonal contraceptives (including: ethinyl estradiol, estradiol, estriol, dienogest, drospirenone, lynestrenol, levonorgestrel) |
The risk of thrombosis when using hormonal contraceptives increases when combined with tranexamic acid |
Increased risk of thrombotic events |
1. Contraindicated to use tranexamic acid for treating menorrhagia in patients taking contraceptives.
2. For other indications of tranexamic acid, it can be used in individuals taking contraceptives but requires special caution.
Note the risk factors: obesity, smoking, especially in individuals over 35 years old. |
| 2 |
Amiodarone |
Domperidone |
Synergistic effect |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated to combine |
| 3 |
Amiodarone |
Fluconazole |
Synergistic effect |
Increased risk of prolonged QT interval, Torsades de Pointes |
1. Contraindicated in patients with congenital or acquired long QT syndrome.
2. In other patient populations, it is best to avoid combining these medications. If combination is necessary, careful assessment of risk/benefit and evaluation of risk factors for each patient, especially electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia), bradycardia, and female gender, should be conducted before prescribing. |
| 4 |
Aspirin |
Ketorolac |
Synergistic effect on gastrointestinal irritation |
Increased risk of serious gastrointestinal bleeding (concurrent use of ketorolac with another NSAID increases the risk of gastrointestinal bleeding by 5 times compared to the combination of two other NSAIDs) |
Combination is contraindicated. Special attention should be paid to the risk of interaction in the case of postoperative pain relief. |
| 5 |
Azithromycin |
Domperidone |
Synergistic increase in effect |
Increased risk of prolonged QT interval, Torsades de Pointes |
Combination is contraindicated. |
| 6 |
Ceftriaxone |
Intravenous infusion solution containing calcium (including calcium chloride, Ringer’s lactate, intravenous nutrition solution containing calcium) |
Calcium – ceftriaxone precipitate formation in lung and kidney tissue when administered intravenously in neonates |
Precipitate formation in the lungs and kidneys, which can lead to death in neonates |
1. Contraindicated for simultaneous use in neonates (< 28 days old).
2. In other subjects, do not mix calcium and ceftriaxone in the same infusion line, administer the two drugs via two separate lines at two different sites, or use each drug sequentially after flushing the infusion line with a compatible solvent. |
| 7 |
Ciprofloxacin |
Domperidone |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated combination |
| 8 |
Clarithromycin |
Methylergometrine |
Clarithromycin strongly inhibits CYP3A4, affecting the metabolism of methylergometrine |
Increased serum concentration of methylergometrine, increased risk of toxicity (vomiting, nausea, limb necrosis, ischemia due to vasospasm…) |
Contraindicated combination |
| 9 |
Clarithromycin |
Domperidone |
Clarithromycin inhibits CYP3A4, affecting the metabolism of domperidone |
Increased serum concentration of domperidone, increased risk of QT prolongation |
Contraindicated combination |
| 10 |
Clarithromycin |
Fluconazole |
Synergistic effect |
Increased risk of QT prolongation, Torsades de Pointes |
1. Contraindicated combination in patients with congenital or acquired long QT syndrome.
2. In other patient populations, it is best to avoid combining these medications. If combination is necessary, careful assessment of risk/benefit and evaluation of risk factors for each patient, especially electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia), bradycardia, and females should be conducted before prescribing. |
| 11 |
Dextromethorphan |
Linezolid |
Serotonin interaction |
Increased risk of serotonin syndrome (high fever, cognitive disturbances, increased reflexes, loss of coordination, muscle twitching, muscle rigidity, seizures, rapid heartbeat, high blood pressure, hyperthermia, sweating, hallucinations, agitation or restlessness…) |
1. Try to avoid the simultaneous use of linezolid and dextromethorphan. It is best to use these medications with a 2-week interval. Consider switching to other drugs in the same class with the same indication and lower risk of interaction. In cases where opioid use is necessary, it may be switched to other opioids that do not have serotonin reuptake inhibition activity (codeine).
2. In cases where treatment cannot be delayed for 2 weeks, and long-term or emergency use of linezolid is mandatory with no alternative medications available, weigh the benefits against the risk of serotonin syndrome. If the benefits outweigh the risks, simultaneous use may still be considered, but the patient must be closely monitored, especially during the first month of concurrent use of both medications. |
| 12 |
Diclofenac |
Ketorolac |
Gastrointestinal irritation interaction |
Increased risk of severe gastrointestinal bleeding (concurrent use of ketorolac with another NSAID increases the risk of gastrointestinal bleeding by 5 times compared to the combination of 2 other NSAIDs) |
Contraindicated combination. Special attention is needed for the risk of interaction in the case of postoperative pain relief. |
| 13 |
Domperidone |
Propofol |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated combination. |
| 14 |
Domperidone |
Sevoflurane |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated combination. |
| 15 |
Domperidone |
Levofloxacin |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated combination |
| 16 |
Domperidone |
Ondansetron |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindicated combination |
| 17 |
Domperidone |
Itraconazole |
Itraconazole inhibits CYP3A4, reducing the metabolism of domperidone |
Increased serum levels of domperidone, increased risk of prolonged QT interval |
Contraindicated combination |
| 18 |
Doxycycline |
Isotretinoin |
Synergistic increase in toxicity |
Increased risk of benign intracranial hypertension (papilledema, headache, nausea and vomiting, and visual disturbances) |
Contraindicated combination |
| 19 |
Erythromycin |
Methylergometrine |
Erythromycin strongly inhibits CYP3A4, reducing the metabolism of methylergometrine |
Increased serum levels of methylergometrine, increased risk of toxicity (vomiting, nausea, peripheral necrosis, ischemic damage due to vasospasm…) |
Contraindicated combination |
| 20 |
Erythromycin |
Fluconazole |
Synergistic increase in effect |
Increased risk of prolonged QT interval, torsades de pointes |
1. Contraindications for combination in patients with congenital or acquired long QT syndrome.
2. In other patient populations, it is best to avoid combining these medications. If combination is necessary, careful assessment of risk/benefit and evaluation of risk factors for each patient, especially electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia), bradycardia, and female gender, should be conducted before prescribing. |
| 21 |
Fluconazole |
Domperidone |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
Contraindications for combination |
| 22 |
Fluconazole |
Ondansetron |
Synergistic effect enhancement |
Increased risk of QT prolongation, Torsades de Pointes |
1. Contraindications for combination in patients with congenital or acquired long QT syndrome.
2. In other patient populations, it is best to avoid combining these drugs. If combination is necessary, careful assessment of risk/benefit and evaluation of risk factors for each patient is required, especially electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia), bradycardia, and females before deciding to prescribe. |
| 23 |
Ibuprofen |
Ketorolac |
Synergistic effect on gastrointestinal irritation |
Increased risk of severe gastrointestinal bleeding (concurrent use of ketorolac with another NSAID increases the risk of gastrointestinal bleeding by 5 times compared to the combination of 2 other NSAIDs) |
Contraindicated combination. Special attention should be paid to the risk of interaction in the case of postoperative pain relief. |
| 24 |
Isotretinoin |
Tetracycline |
Synergistic increase in toxicity |
Increased risk of benign intracranial hypertension (papilledema, headache, nausea and vomiting, visual disturbances) |
Contraindicated combination |
| 25 |
Itraconazole |
Methylergometrine |
Itraconazole strongly inhibits CYP3A4, reducing the metabolism of methylergometrine |
Increased serum levels of methylergometrine, increasing the risk of toxicity (vomiting, nausea, peripheral necrosis, ischemia due to vasospasm) |
Contraindicated combination |
| 26 |
Linezolid |
Nefopam |
Nefopam inhibits the reuptake of noradrenaline and serotonin in the nervous system |
Increased risk of central nervous system stimulation (seizures, hallucinations, and agitation) |
Contraindicated combination |
| 27 |
Linezolid |
Fentanyl |
Synergistic serotonin effect |
Increased risk of serotonin syndrome (high fever, cognitive disturbances, increased reflexes, loss of coordination, muscle twitching, muscle rigidity, seizures, tachycardia, hypertension, hyperthermia, sweating, hallucinations, agitation or restlessness…) |
1. Try to avoid using linezolid and fentanyl simultaneously. It is best to use these medications at least 2 weeks apart. Consider switching to other medications in the same class with similar indications and a lower risk of interaction. In cases where opioid use is necessary, it may be possible to switch to other opioids that do not have serotonin reuptake inhibition activity (morphine, codeine, oxycodone, buprenorphine).
2. In cases where treatment cannot be delayed for 2 weeks, and long-term or emergency use of linezolid is mandatory with no alternative medications available, weigh the benefits against the risk of serotonin syndrome. If the benefits outweigh the risks, simultaneous use may still be possible but requires close monitoring of the patient, especially during the first month of concurrent use of both medications. |
| 28 |
Nitroglycerin |
Sildenafil |
Synergistic increase in cyclic guanosine monophosphate (cGMP) levels leading to vasodilation |
Significantly increased hypotensive effect |
Contraindicated to combine. If used, the two medications should be taken at least 24 hours apart |
| 29 |
Iohexol |
Metformin |
The risk of acute kidney injury related to both metformin and iodinated contrast agents. Acute kidney injury increases the risk of lactic acidosis. |
Increased risk of lactic acidosis and acute kidney injury |
1. Patients with eGFR > 30 ml/min/1.73m2 and no evidence of acute kidney injury are indicated for intravenous contrast injection or arterial contrast injection involving secondary kidney exposure (e.g., injecting into the right heart, pulmonary artery, carotid artery, subclavian artery, coronary artery, mesenteric artery, or below the renal artery): continue using metformin as usual.
2. Patients (1) with eGFR < 30 ml/min/1.73m2 receiving intravenous contrast, arterial contrast involving secondary kidney exposure, or (2) patients receiving arterial contrast involving primary kidney exposure (e.g., injecting into the left heart, thoracic aorta, abdominal aorta above the renal artery, or renal artery) or (3) with kidney injury: Stop metformin before or at the time of performing the imaging diagnostic procedure and do not resume until at least 48 hours later. After 48 hours, only resume metformin after kidney function has been reassessed and confirmed.stable.
* Note:
– Risk factors: renal failure, heart failure, inadequate or lack of fluid, high doses of contrast agents, or concurrent use of other nephrotoxic drugs.
– This interaction recommendation does not apply in the case of injecting iodinated contrast agents for hysterosalpingography. |
| 30 |
Linezolid |
Methyldopa |
Unclear |
Increased risk of hypertensive crisis (headache, palpitations, neck stiffness) |
Contraindicated combination |
