Drug Interaction Report
No drug interactions found, but 35 warnings to review for the following 2 drugs:
- Headache Relief (acetaminophen / caffeine)
- levothyroxine
Drug interactions
No drug interactions were found between the drugs in your list. However, this does not necessarily mean no drug interactions exist. Always consult your healthcare provider.
Food/lifestyle interactions
Major food/lifestyle interactions
Major:Food/Lifestyle acetaminophen
Applies to: Headache Relief (acetaminophen / caffeine)
Acetaminophen may cause liver damage and taking it with alcohol may increase that risk.
You should avoid or limit the use of alcohol while being treated with acetaminophen.
Call your doctor immediately if you have:
- fever
- chills
- joint pain or swelling
- excessive tiredness or weakness
- unusual bleeding or bruising
- skin rash or itching
- loss of appetite
- nausea
- vomiting
- dark colored urine
- yellowing of the skin or the whites of your eyes
These may be symptoms of liver damage.
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.
Moderate food/lifestyle interactions
Moderate:Food/Lifestyle levothyroxine
Applies to: levothyroxine
The timing of meals relative to your oral levothyroxine dose can affect the absorption of the medication.
Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects.
In addition, absorption of levothyroxine may be decreased and/or delayed by foods such as:
- soybean flour
- cotton seed meal
- walnuts
- dietary fiber
- calcium
- calcium fortified juices
- grapefruit or grapefruit juice
These foods should be avoided within several hours of dosing if possible.
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.
Moderate:multivitamins with minerals levothyroxine
Applies to: levothyroxine
Using multivitamins with minerals together with levothyroxine may decrease the effects of levothyroxine.
You should separate the administration of levothyroxine and multivitamins with minerals by at least 4 hours.
If your doctor does prescribe these medications together, you may need a dose adjustment or special test 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.
Minor food/lifestyle interactions
Minor:Food/Lifestyle caffeine
Applies to: Headache Relief (acetaminophen / caffeine)
The effect of grapefruit juice on the pharmacologic activity of caffeine is controversial. One report suggests that grapefruit juice increases the effect of caffeine. The proposed mechanism is inhibition of cytochrome P-450 metabolism of caffeine. However, a well-conducted pharmacokinetic/pharmacodynamic study did not demonstrate this effect. The clinical significance of this potential interaction is unknown.
The information above is from our professional interaction data. Consumer information is not available for this interaction.
Disease interactions
31 potential interactionsApplies to: 23 conditions, including High Blood Pressure, Depression, GERD, Heart Attack, and Angina.
Adrenal Insufficiency
Major:levothyroxine
Levothyroxine has a major potential interaction with Adrenal Insufficiency.
The use of thyroid hormones is contraindicated in patients with uncorrected adrenal insufficiency. Thyroid hormones increase tissue demand for adrenocortical hormones and may precipitate acute adrenal crisis. In patients with controlled adrenal insufficiency or other endocrine disorders, therapy for these concomitant disorders may need to be adjusted following thyroid replacement, since hypothyroidism often obscure or diminish the signs and symptoms of these conditions. Clinical monitoring of thyroid and adrenal function as well as any other appropriate endocrine function is recommended during thyroid hormone therapy.
Alcoholism
Major:Headache Relief
The acetaminophen in Headache Relief has a major potential interaction with Alcoholism.
Chronic alcohol abusers may be at increased risk of hepatotoxicity during treatment with acetaminophen (APAP). Severe liver injury, including cases of acute liver failure resulting in liver transplant and death, has been reported in patients using acetaminophen. Therapy with acetaminophen should be administered cautiously, if at all, in patients who consume three or more alcoholic drinks a day. In general, patients should avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure. They should also be advised to seek medical attention if they experience signs and symptoms of liver injury such as fever, rash, anorexia, nausea, vomiting, fatigue, right upper quadrant pain, dark urine, and jaundice.
Angina
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Angina.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
Dehydration
Major:Headache Relief
The acetaminophen in Headache Relief has a major potential interaction with Dehydration.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Depression
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Depression.
The use of CNS stimulants can cause psychotic symptoms, suicidal ideation, and aggression, and can exacerbate symptoms of behavior disturbance and thought disorder; CNS stimulants may induce a manic or mixed episode in patients with bipolar disorder. Psychiatric symptoms have been reported in patients with and without history of psychiatric disorders. All patients (particularly those with psychotic or bipolar disorders) should be monitored closely, especially during treatment initiation and at times of dose changes. Extreme caution should be exercised when CNS stimulants are given to patients with a history of psychosis, depression, mania, or bipolar disorder. Prior to initiating therapy, all patients should be screened for risk factors for developing a manic episode (e.g., comorbid or history of depressive symptoms or family history of suicide, bipolar disease, or depression). If any psychiatric symptoms emerge or are exacerbated, treatment suspension should be considered. Some CNS stimulants are contraindicated in patients with marked agitation or anxiety.
Diabetes Insipidus
Moderate:levothyroxine
Levothyroxine has a moderate potential interaction with Diabetes Insipidus.
Since hypothyroidism often obscure or diminish the signs and symptoms of endocrine disorders such as diabetes mellitus or diabetes insipidus, thyroid replacement therapy may aggravate the intensity of symptoms associated with these conditions. Patients with endocrine disorders should be monitored more closely during thyroid hormone therapy, and their medication regimen adjusted accordingly. If thyroid medication is later discontinued, a downward readjustment of insulin or oral hypoglycemic agent may be necessary in patients with diabetes mellitus to avoid hypoglycemia.
Diabetes Mellitus
Moderate:levothyroxine
Levothyroxine has a moderate potential interaction with Diabetes Mellitus.
Since hypothyroidism often obscure or diminish the signs and symptoms of endocrine disorders such as diabetes mellitus or diabetes insipidus, thyroid replacement therapy may aggravate the intensity of symptoms associated with these conditions. Patients with endocrine disorders should be monitored more closely during thyroid hormone therapy, and their medication regimen adjusted accordingly. If thyroid medication is later discontinued, a downward readjustment of insulin or oral hypoglycemic agent may be necessary in patients with diabetes mellitus to avoid hypoglycemia.
GERD
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with GERD.
Methylxanthines increase gastric acidity and may also relax lower esophageal sphincter, which can lead to gastric reflux into the esophagus. Therapy with products containing methylxanthines should be administered cautiously in patients with significant gastroesophageal reflux.
Heart Attack
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Heart Attack.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
Heart Disease
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Heart Disease.
Many CNS stimulants are contraindicated in patients with significant cardiovascular impairment such as uncompensated heart failure, severe coronary disease, severe hypertension (including that associated with hyperthyroidism or pheochromocytoma), cardiac structural abnormalities, serious arrhythmias, etc. Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended dosages for attention deficit hyperactivity disorder; use of these agents should be avoided in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease. Additionally, stroke, myocardial infarction, chest pain, syncope, arrhythmias, and other symptoms have been reported in adults under treatment. A careful assessment of the cardiovascular status should be done in patients being considered for treatment. This includes family history, physical exam, and further cardiac evaluation (EKG and echocardiogram). Patients who develop symptoms should have a detailed cardiac evaluation and if needed, treatment should be suspended.
Major:levothyroxine
Levothyroxine has a major potential interaction with Heart Disease.
Thyroid hormones cause increases in myocardial contractility and heart rate as a result of increased metabolic demands and oxygen consumption. Therapy with thyroid hormones should be administered cautiously and initiated at reduced dosages in patients with cardiovascular disorders such as angina, coronary artery disease, and hypertension. Clinical monitoring of cardiovascular function is recommended. If chest pain or exacerbation of cardiovascular disease occurs, the dosage of thyroid hormone should be reduced, even at the expense of achieving euthyroid state. Thyroid hormones should not be administered to patients with an acute myocardial infarction that is not complicated by hypothyroidism.
High Blood Pressure
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with High Blood Pressure.
CNS stimulants increase blood pressure and heart rate; the use of some agents may be contraindicated in patients with severe/uncontrolled hypertension. Caution should be used when administering to patients with preexisting high blood pressure (even mild hypertension) and other cardiovascular conditions. All patients under treatment should be regularly monitored for potential tachycardia and hypertension.
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with High Blood Pressure.
Many CNS stimulants are contraindicated in patients with significant cardiovascular impairment such as uncompensated heart failure, severe coronary disease, severe hypertension (including that associated with hyperthyroidism or pheochromocytoma), cardiac structural abnormalities, serious arrhythmias, etc. Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended dosages for attention deficit hyperactivity disorder; use of these agents should be avoided in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease. Additionally, stroke, myocardial infarction, chest pain, syncope, arrhythmias, and other symptoms have been reported in adults under treatment. A careful assessment of the cardiovascular status should be done in patients being considered for treatment. This includes family history, physical exam, and further cardiac evaluation (EKG and echocardiogram). Patients who develop symptoms should have a detailed cardiac evaluation and if needed, treatment should be suspended.
Major:levothyroxine
Levothyroxine has a major potential interaction with High Blood Pressure.
Thyroid hormones cause increases in myocardial contractility and heart rate as a result of increased metabolic demands and oxygen consumption. Therapy with thyroid hormones should be administered cautiously and initiated at reduced dosages in patients with cardiovascular disorders such as angina, coronary artery disease, and hypertension. Clinical monitoring of cardiovascular function is recommended. If chest pain or exacerbation of cardiovascular disease occurs, the dosage of thyroid hormone should be reduced, even at the expense of achieving euthyroid state. Thyroid hormones should not be administered to patients with an acute myocardial infarction that is not complicated by hypothyroidism.
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with High Blood Pressure.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
Hyperthyroidism
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Hyperthyroidism.
Many CNS stimulants are contraindicated in patients with significant cardiovascular impairment such as uncompensated heart failure, severe coronary disease, severe hypertension (including that associated with hyperthyroidism or pheochromocytoma), cardiac structural abnormalities, serious arrhythmias, etc. Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended dosages for attention deficit hyperactivity disorder; use of these agents should be avoided in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease. Additionally, stroke, myocardial infarction, chest pain, syncope, arrhythmias, and other symptoms have been reported in adults under treatment. A careful assessment of the cardiovascular status should be done in patients being considered for treatment. This includes family history, physical exam, and further cardiac evaluation (EKG and echocardiogram). Patients who develop symptoms should have a detailed cardiac evaluation and if needed, treatment should be suspended.
Major:levothyroxine
Levothyroxine has a major potential interaction with Hyperthyroidism.
The use of thyroid hormones is contraindicated in patients with untreated thyrotoxicosis of any etiology, since thyroid hormones may exacerbate the condition.
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Hyperthyroidism.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
Liver Disease
Major:Headache Relief
The acetaminophen in Headache Relief has a major potential interaction with Liver Disease.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Liver Disease.
In general, CNS stimulants are extensively metabolized by the liver. Their plasma clearance may be decreased and their half-life prolonged in patients with impaired hepatic function. Therapy with CNS stimulants should be administered cautiously in patients with moderate to severe liver disease, and the dosage should be adjusted accordingly in certain agents. Additionally, postmarketing reports have shown that atomoxetine can cause severe liver injury; laboratory testing should be done at the first sign/symptom of liver dysfunction (jaundice, dark urine, upper quadrant tenderness) and treatment should be discontinued in patients with evidence of liver injury.
Malnourishment
Major:Headache Relief
The acetaminophen in Headache Relief has a major potential interaction with Malnourishment.
Acetaminophen is contraindicated in patients with severe hepatic impairment or severe active liver disease. Patients with hepatic impairment may be at increased risk of toxicity. Severe liver injury, including cases of acute liver failure and death, have been reported in patients using this drug. Clinical monitoring of hepatic function is recommended. Caution is advised if using acetaminophen in patients with chronic malnutrition or severe hypovolemia. Instruct patients to avoid drinking alcohol while taking acetaminophen-containing medications. Patients should be warned not to exceed the maximum recommended total daily dosage of acetaminophen (4 g/day in adults and children 12 years of age or older), and to read all prescription and over-the-counter medication labels to ensure they are not taking multiple acetaminophen-containing products, or check with a healthcare professional if they are unsure.
Peptic Ulcer
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Peptic Ulcer.
Methylxanthines are known to stimulate peptic acid secretion. Therapy with products containing methylxanthines should be administered with extreme caution in patients with active peptic ulcer disease. Some manufacturers consider their use to be contraindicated under such circumstance.
Peripheral Arterial Disease
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Peripheral Arterial Disease.
Many CNS stimulants are contraindicated in patients with significant cardiovascular impairment such as uncompensated heart failure, severe coronary disease, severe hypertension (including that associated with hyperthyroidism or pheochromocytoma), cardiac structural abnormalities, serious arrhythmias, etc. Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended dosages for attention deficit hyperactivity disorder; use of these agents should be avoided in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease. Additionally, stroke, myocardial infarction, chest pain, syncope, arrhythmias, and other symptoms have been reported in adults under treatment. A careful assessment of the cardiovascular status should be done in patients being considered for treatment. This includes family history, physical exam, and further cardiac evaluation (EKG and echocardiogram). Patients who develop symptoms should have a detailed cardiac evaluation and if needed, treatment should be suspended.
Phenylketonuria
Moderate:Headache Relief
The acetaminophen in Headache Relief has a moderate potential interaction with Phenylketonuria.
Several oral acetaminophen and acetaminophen-combination products, particularly flavored chewable tablets, contain the artificial sweetener, aspartame (NutraSweet). Aspartame is converted to phenylalanine in the gastrointestinal tract following ingestion. Chewable and effervescent formulations of acetaminophen products may also contain phenylalanine. The aspartame/phenylalanine content should be considered when these products are used in patients who must restrict their intake of phenylalanine (i.e. phenylketonurics).
Pheochromocytoma
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Pheochromocytoma.
Many CNS stimulants are contraindicated in patients with significant cardiovascular impairment such as uncompensated heart failure, severe coronary disease, severe hypertension (including that associated with hyperthyroidism or pheochromocytoma), cardiac structural abnormalities, serious arrhythmias, etc. Sudden death has been reported in patients with structural cardiac abnormalities or other serious cardiac disease who are treated with CNS stimulants at the recommended dosages for attention deficit hyperactivity disorder; use of these agents should be avoided in patients with known structural cardiac abnormalities, cardiomyopathy, serious cardiac arrhythmia, coronary artery disease, or other serious cardiac disease. Additionally, stroke, myocardial infarction, chest pain, syncope, arrhythmias, and other symptoms have been reported in adults under treatment. A careful assessment of the cardiovascular status should be done in patients being considered for treatment. This includes family history, physical exam, and further cardiac evaluation (EKG and echocardiogram). Patients who develop symptoms should have a detailed cardiac evaluation and if needed, treatment should be suspended.
Post MI Syndrome
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Post MI Syndrome.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
Psychosis
Major:Headache Relief
The caffeine in Headache Relief has a major potential interaction with Psychosis.
The use of CNS stimulants can cause psychotic symptoms, suicidal ideation, and aggression, and can exacerbate symptoms of behavior disturbance and thought disorder; CNS stimulants may induce a manic or mixed episode in patients with bipolar disorder. Psychiatric symptoms have been reported in patients with and without history of psychiatric disorders. All patients (particularly those with psychotic or bipolar disorders) should be monitored closely, especially during treatment initiation and at times of dose changes. Extreme caution should be exercised when CNS stimulants are given to patients with a history of psychosis, depression, mania, or bipolar disorder. Prior to initiating therapy, all patients should be screened for risk factors for developing a manic episode (e.g., comorbid or history of depressive symptoms or family history of suicide, bipolar disease, or depression). If any psychiatric symptoms emerge or are exacerbated, treatment suspension should be considered. Some CNS stimulants are contraindicated in patients with marked agitation or anxiety.
Renal Dysfunction
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Renal Dysfunction.
Overall CNS stimulants should be administered with caution in patients with significantly impaired renal function as the reduction in the rate of elimination may alter the therapeutic response. The dosage should be adjusted accordingly in certain agents.
Seizures
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Seizures.
Due to general central nervous system stimulation, therapy with CNS stimulant drugs may cause seizures. These drugs may lower the convulsive threshold in patients with history of seizures, with prior electroencephalogram (EEG) abnormalities without seizures, and very rarely, without history of seizures and no prior EEG evidence of seizures. Therapy with CNS stimulants should be used with caution in patients with or predisposed to seizures. If seizures occur, therapy should be discontinued.
Moderate:levothyroxine
Levothyroxine has a moderate potential interaction with Seizures.
Thyroid hormones may alter the seizure threshold. Seizures have been reported rarely following the initiation of levothyroxine therapy. Therapy with thyroid hormones should be administered cautiously in patients predisposed to seizures.
Tachyarrhythmia
Moderate:Headache Relief
The caffeine in Headache Relief has a moderate potential interaction with Tachyarrhythmia.
Like other methylxanthines, caffeine at high dosages may be associated with positive inotropic and chronotropic effects on the heart. Caffeine may also produce an increase in systemic vascular resistance, resulting in elevation of blood pressure. Therapy with products containing caffeine should be administered cautiously in patients with severe cardiac disease, hypertension, hyperthyroidism, or acute myocardial injury. Some clinicians recommend avoiding caffeine in patients with symptomatic cardiac arrhythmias and/or palpitations and during the first several days to weeks after an acute myocardial infarction.
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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Further information
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.