Skip to main content

Can you take Carbidopa / levodopa with Guanfacine?

1 drug interaction and 27 additional warnings found for the following 2 drugs:

Add/remove drugs

Drug interactions

Moderate drug interactions

Moderate:

levodopa guanFACINE

Applies to: carbidopa / levodopa and guanfacine

Using levodopa together with guanFACINE may have additive effects in lowering your blood pressure and/or may increase the risk of side effects such as dizziness, lightheadedness, fainting, changes in pulse or heart rate and/or sudden somnolence and impairment in thinking and judgment.

These side effects are most likely to be seen:

  • at the beginning of treatment
  • following a dose increase
  • when treatment is restarted after an interruption

Let your doctor know if you develop these symptoms or if they become troublesome.

You should avoid the use of alcohol while being treated with these medications.

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.

Food/lifestyle interactions

Major food/lifestyle interactions

Major:

guanFACINE Food/Lifestyle

Applies to: guanfacine

Avoid consuming grapefruit or grapefruit juice during treatment with guanFACINE, as it may increase blood levels and effects of the medication. This may cause blood pressure to fall excessively, especially when you rise from a sitting or lying position. The risk of other side effects such as drowsiness, dizziness, lightheadedness, fainting, headache, palpitations, and heart rate changes may also increase.

Additionally, you should avoid or limit the use of alcohol while being treated with guanFACINE. Combining the medication with alcohol can intensify sedative and blood pressure lowering effects, which may increase the risk of falls and injury.

Avoid driving or operating hazardous machinery until you know how the medication affects you, and use caution when getting up from a sitting or lying position.

If you are using a long-acting or extended-release formulation of the medication, make sure you do not take it with a high-fat meal. Doing so results in increased absorption and elevated blood levels of the medication.

Talk to your doctor or pharmacist if you have any questions or concerns.

Moderate food/lifestyle interactions

Moderate:

levodopa Food/Lifestyle

Applies to: carbidopa / levodopa

Alcohol can increase the nervous system side effects of levodopa such as:

  • dizziness
  • drowsiness
  • difficulty concentrating

Some people may also experience impairment in thinking and judgment.

You should avoid or limit the use of alcohol while being treated with levodopa.

You may experience reduced effectiveness of levodopa in the presence of foods or enteral (tube) feedings with a high protein content. This may make the symptoms of Parkinson's disease worse.

Talk with your doctor or nutrition counselor about the best foods to eat while you are taking this medication. Contact your doctor if your condition changes.

Moderate:

levodopa multivitamins with minerals

Applies to: carbidopa / levodopa

Levodopa and multivitamins with minerals should not be taken orally at the same time. Products that contain iron may interfere with the absorption of levodopa and reduce its effectiveness.

You should separate the dosing of these medications by as much as possible. Contact your doctor if your Parkinson symptoms worsen.

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.

Disease interactions

24 potential interactions Applies to: 19 conditions, including Depression, Asthma, COPD, Hypotension, and Peripheral Arterial Disease.

Asthma

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Asthma.

Because of the risk of bronchospasm, use of levodopa in patients with asthma, COPD, or other chronic underlying lung disease is not recommended.

Cardiovascular Conditions and Disorders

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Cardiovascular Conditions and Disorders.

Cardiac irregularities occur infrequently in patients on dopamine agonists. The initial administration and titration is recommended to occur under close cardiac monitoring in a facility equipped for intensive cardiac care. Adverse cardiac affects may include palpitation, sinus tachycardia, ventricular tachycardia, extrasystole, atrial flutter or fibrillation, or block of AV conduction.

Cerebrovascular Insufficiency

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Cerebrovascular Insufficiency.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system, resulting in decreases in heart rate, peripheral and renovascular resistance, and blood pressure. Therapy with these agents should be administered cautiously in patients with hypotension or conditions that may be exacerbated by decreased blood pressure and perfusion, such as coronary insufficiency, peripheral vascular disease (e.g., Raynaud's syndrome), cerebrovascular disease, or recent myocardial infarction.

COPD

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with COPD.

Because of the risk of bronchospasm, use of levodopa in patients with asthma, COPD, or other chronic underlying lung disease is not recommended.

Depression

Moderate:

carbidopa / levodopa

The carbidopa in carbidopa / levodopa has a moderate potential interaction with Depression.

Caution and observation is recommended when treating patients with carbidopa, as depression with concomitant suicidal tendencies may develop or be exacerbated.

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Depression.

Central alpha-2 adrenoreceptor agonists may occasionally cause mental depression and should be used cautiously in patients with a history of depression.

Gastrointestinal Hemorrhage

Moderate:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a moderate potential interaction with Gastrointestinal Hemorrhage.

The use of levodopa, especially in combinations with carbidopa, has been associated with an increase in the frequency of gastrointestinal hemorrhage. Therapy with levodopa should be administered cautiously in patients with a history of peptic ulcer disease or gastrointestinal hemorrhage.

Glaucoma, Narrow Angle

Major:

carbidopa / levodopa

The carbidopa in carbidopa / levodopa has a major potential interaction with Glaucoma, Narrow Angle.

Carbidopa-levodopa products are contraindicated in patients with narrow-angle glaucoma.

Glaucoma/Intraocular Hypertension

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Glaucoma/Intraocular Hypertension.

The use of levodopa is contraindicated in patients with acute closed-angle glaucoma. Levodopa (with or without carbidopa) may be used in patients with open-angle glaucoma who are receiving appropriate therapy.

Heart Block

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Heart Block.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system. Heart rate is decreased, which may lead to or exacerbate sinus bradycardia and atrioventricular block. Therapy with central alpha-2 adrenoreceptor agonists should be administered cautiously in patients with conduction disturbances such as sinus node dysfunction or AV nodal disease.

Hyperkinetic Syndrome of Childhood

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Hyperkinetic Syndrome of Childhood.

The safety and effectiveness of guanfacine in children under 12 years of age has not been demonstrated and its use in this age group is not recommended. However, there have been some spontaneous postmarketing reports of mania and aggressive behavioral changes in pediatric patients with attention- deficit hyperactivity disorder (ADHD) that received this drug. All patients had medical or family risks of bipolar disorder, and all of them recovered after treatment discontinuation. Hallucinations have also been reported in pediatric patients receiving guanfacine for the treatment of ADHD.

Hypotension

Moderate:

carbidopa / levodopa

The carbidopa and levodopa in carbidopa / levodopa both have a moderate potential interaction with Hypotension.

Dopamine agonists may impair the systemic regulation of blood pressure, with resultant orthostatic hypotension at any time, but especially during dose escalation. Additionally, patients with Parkinson's disease may have an impaired capacity to respond to an orthostatic challenge. For these reasons, patients with Parkinson's disease (or restless legs syndrome) who are being treated with dopaminergic agonists typically require careful monitoring for signs/symptoms of orthostatic hypotension, especially during dose escalation, and should be advised of this risk.

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Hypotension.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system, resulting in decreases in heart rate, peripheral and renovascular resistance, and blood pressure. Therapy with these agents should be administered cautiously in patients with hypotension or conditions that may be exacerbated by decreased blood pressure and perfusion, such as coronary insufficiency, peripheral vascular disease (e.g., Raynaud's syndrome), cerebrovascular disease, or recent myocardial infarction.

Ischemic Heart Disease

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Ischemic Heart Disease.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system, resulting in decreases in heart rate, peripheral and renovascular resistance, and blood pressure. Therapy with these agents should be administered cautiously in patients with hypotension or conditions that may be exacerbated by decreased blood pressure and perfusion, such as coronary insufficiency, peripheral vascular disease (e.g., Raynaud's syndrome), cerebrovascular disease, or recent myocardial infarction.

Liver Disease

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Liver Disease.

The pharmacokinetics of levodopa have not been studied in patients with hepatic or renal impairment. Therapy with levodopa should be administered cautiously in patients with liver or disease. Periodic monitoring of hepatic and renal function is recommended during extended therapy.

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Liver Disease.

Normally, approximately 50% of a guanfacine dose is eliminated unchanged by the kidney and the rest metabolized by the liver. However, neither the parent drug nor its metabolites accumulate significantly during chronic dosing in patients with severe renal impairment due to increased hepatic metabolism of the drug in these patients. Thus, initial dosage adjustments are generally not necessary in renal impairment. Dosage titration, however, should be made cautiously if hepatic function is also compromised. The pharmacokinetics of guanfacine has not been studied in patients with liver disease. The manufacturer recommends caution when the drug is used in such patients.

Peripheral Arterial Disease

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Peripheral Arterial Disease.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system, resulting in decreases in heart rate, peripheral and renovascular resistance, and blood pressure. Therapy with these agents should be administered cautiously in patients with hypotension or conditions that may be exacerbated by decreased blood pressure and perfusion, such as coronary insufficiency, peripheral vascular disease (e.g., Raynaud's syndrome), cerebrovascular disease, or recent myocardial infarction.

Psychosis

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Psychosis.

The use of dopamine agonists has been associated with psychiatric effects such as hallucinations, psychosis, confusion, anxiety, mania, hypomania, depression, rapid mood cycling, nightmares, and hypersexuality. Therapy with dopamine agonists should be administered cautiously in psychotic patients and all patients should be carefully observed for development of depression and suicidal tendencies.

Moderate:

carbidopa / levodopa

The carbidopa and levodopa in carbidopa / levodopa both have a moderate potential interaction with Psychosis.

Ordinarily, patients with major psychotic disorder should not be treated with dopaminergic antiparkinsonian agents, because of the risk of exacerbating psychosis. Hallucinations and psychotic-like behavior have been reported with dopaminergic medications. In addition, certain medications used to treat psychosis may exacerbate the symptoms of Parkinson's disease and may decrease the effectiveness of these drugs. The use of bromocriptine in patients with severe psychotic disorders is not recommended.

Renal Dysfunction

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Renal Dysfunction.

The pharmacokinetics of levodopa have not been studied in patients with hepatic or renal impairment. Therapy with levodopa should be administered cautiously in patients with liver or disease. Periodic monitoring of hepatic and renal function is recommended during extended therapy.

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Renal Dysfunction.

Normally, approximately 50% of a guanfacine dose is eliminated unchanged by the kidney and the rest metabolized by the liver. However, neither the parent drug nor its metabolites accumulate significantly during chronic dosing in patients with severe renal impairment due to increased hepatic metabolism of the drug in these patients. Thus, initial dosage adjustments are generally not necessary in renal impairment. Dosage titration, however, should be made cautiously if hepatic function is also compromised. The pharmacokinetics of guanfacine has not been studied in patients with liver disease. The manufacturer recommends caution when the drug is used in such patients.

Sinus Node Dysfunction

Moderate:

guanfacine

guanFACINE has a moderate potential interaction with Sinus Node Dysfunction.

Central alpha-2 adrenoreceptor agonists reduce sympathetic outflow from the central nervous system. Heart rate is decreased, which may lead to or exacerbate sinus bradycardia and atrioventricular block. Therapy with central alpha-2 adrenoreceptor agonists should be administered cautiously in patients with conduction disturbances such as sinus node dysfunction or AV nodal disease.

Skin Cancer

Major:

carbidopa / levodopa

The levodopa in carbidopa / levodopa has a major potential interaction with Skin Cancer.

The use of levodopa is considered by manufacturers to be contraindicated in patients with a history of melanoma or in patients with suspicious, undiagnosed skin lesions. Levodopa reportedly may activate malignant melanoma, although some investigators have found a causal relationship to be tenuous.

Sleep Disorders

Moderate:

carbidopa / levodopa

The carbidopa and levodopa in carbidopa / levodopa both have a moderate potential interaction with Sleep Disorders.

Patients treated with products containing carbidopa and levodopa report excessive somnolence and falling asleep while engaged in daily activities, sometimes with no warning sign of drowsiness. Advise patients about the risks, especially those suffering from sleep disorders or using concomitant sedating medications.

More resources

carbidopa / levodopa

A total of 535 drugs are known to interact with carbidopa / levodopa.

guanfacine

A total of 535 drugs are known to interact with guanfacine.

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor 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.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.