Meta Information
ID:levodopa
Name:
Schema Version:AIM-2.0
Interactions
Target id:
/dietary/high-protein-meal
Target name:
High-Protein Meal
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
2
Description:
Large neutral amino acids from dietary protein compete with levodopa for absorption from the intestine and for transport across the blood-brain barrier, significantly reducing its effectiveness.
Actionable advice:
Take levodopa at least 1 hour before or 2 hours after a high-protein meal (e.g., meat, fish, dairy, protein shakes).
Target id:
/class/iron-supplements
Target name:
Iron Supplements
Severity:
major
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
2
Hours after target:
2
Description:
Iron salts can form a chelate complex with levodopa in the gastrointestinal tract, which prevents its absorption and reduces the amount of medication reaching the brain.
Actionable advice:
Separate levodopa and iron supplement doses by at least 2 hours.
Target id:
/class/maois
Target name:
Non-selective MAO Inhibitors
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Combining levodopa with non-selective MAOIs (e.g., phenelzine, tranylcypromine) can block dopamine metabolism, leading to a massive buildup and a potentially fatal hypertensive crisis.
Actionable advice:
Avoid this combination completely; stop non-selective MAOIs at least 14 days before starting levodopa.
Target id:
/class/antipsychotics
Target name:
Antipsychotic Medications
Severity:
major
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
null
Description:
Most antipsychotic drugs work by blocking dopamine D2 receptors in the brain, directly opposing the therapeutic action of levodopa, which aims to increase dopamine levels.
Actionable advice:
Avoid using antipsychotics, especially typical ones like haloperidol; if necessary, use with extreme caution under specialist supervision.
Target id:
/condition/glaucoma
Target name:
Narrow-Angle Glaucoma
Severity:
major
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa can cause pupil dilation (mydriasis), which may trigger a sudden and dangerous increase in eye pressure (acute attack) in individuals with narrow-angle glaucoma.
Actionable advice:
Do not use if you have narrow-angle glaucoma; use with caution and monitoring in open-angle glaucoma.
Target id:
/intervention/metoclopramide
Target name:
Metoclopramide
Severity:
major
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
null
Description:
Metoclopramide is a dopamine receptor antagonist, which directly counteracts the effects of levodopa in the brain and can worsen Parkinson's symptoms.
Actionable advice:
Avoid this combination completely.
Target id:
/class/antihypertensives
Target name:
Antihypertensive Medications
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa can cause postural hypotension (a drop in blood pressure upon standing). This effect can be amplified when taken with other medications designed to lower blood pressure.
Actionable advice:
Monitor blood pressure closely, especially when starting or adjusting doses, and rise slowly from a seated or lying position.
Target id:
/intervention/vitamin-b6
Target name:
Vitamin B6 (Pyridoxine)
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
null
Description:
High doses of Vitamin B6 can increase the conversion of levodopa to dopamine in the body before it reaches the brain, reducing its effectiveness and increasing side effects. This interaction is mostly negated by co-administered carbidopa or benserazide.
Actionable advice:
Avoid high-dose Vitamin B6 supplements unless they are part of a standard multivitamin and you are taking a levodopa/carbidopa combination.
Target id:
/class/tricyclic-antidepressants
Target name:
Tricyclic Antidepressants
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
This combination can rarely lead to hypertension and dyskinesia (involuntary movements), and may also increase the risk of postural hypotension.
Actionable advice:
Use this combination with caution and monitor blood pressure and for any new involuntary movements.
Target id:
/class/cns-depressants
Target name:
CNS Depressants
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa can cause drowsiness and sudden sleep onset. Combining it with other central nervous system depressants like benzodiazepines, opioids, or alcohol can greatly enhance this sedative effect.
Actionable advice:
Exercise extreme caution when using with other sedating substances, and avoid activities requiring mental alertness like driving.
Target id:
/condition/history-of-melanoma
Target name:
History of Melanoma
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa is a precursor for melanin, the pigment in skin. There is a theoretical concern that it could activate or promote the growth of malignant melanoma.
Actionable advice:
Avoid use if you have a history of suspicious, undiagnosed skin lesions or melanoma.
Target id:
/condition/peptic-ulcer-disease
Target name:
Peptic Ulcer Disease
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa may increase the risk of gastrointestinal hemorrhage in patients with a history of peptic ulcers.
Actionable advice:
Use with caution if you have a history of peptic ulcer disease and monitor for signs of GI bleeding.
Target id:
/class/inhalational-anesthetics
Target name:
Inhalational Anesthetics
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
null
Description:
General anesthesia, particularly with agents like halothane, may sensitize the heart to the effects of dopamine, increasing the risk of cardiac arrhythmias when combined with levodopa.
Actionable advice:
Inform your anesthesiologist that you are taking levodopa well before any scheduled surgery.
Target id:
/intervention/phenytoin
Target name:
Phenytoin
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
null
Description:
The anticonvulsant drug phenytoin may reduce the therapeutic effects of levodopa, potentially by interfering with dopamine activity in the brain.
Actionable advice:
Avoid this combination if possible; monitor for reduced effectiveness of levodopa if co-administration is necessary.
Target id:
/intervention/papaverine
Target name:
Papaverine
Severity:
moderate
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
null
Description:
Papaverine, a vasodilator, may block dopamine receptors and antagonize the beneficial effects of levodopa.
Actionable advice:
Avoid this combination due to the potential for reduced levodopa efficacy.
Target id:
/dietary/meal
Target name:
Any Caloric Meal
Severity:
moderate
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
0.5
Hours after target:
1.5
Description:
Food in the stomach can delay gastric emptying and interfere with the absorption of levodopa, leading to a delayed or reduced effect. This is especially true for high-protein, high-fat, or high-fiber meals.
Actionable advice:
For best absorption, take levodopa on an empty stomach, 30 minutes before or 90 minutes after a meal.
Target id:
/class/antacids
Target name:
Antacids
Severity:
minor
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
1
Description:
Antacids can alter stomach pH and gastric emptying time, which may change the rate of levodopa absorption. This can lead to more rapid 'peak' effects and potentially worsen motor fluctuations.
Actionable advice:
Separate doses of levodopa and antacids by at least 1 hour.
Target id:
/biomarker/urine-ketones
Target name:
Urine Ketone Test
Severity:
minor
Interaction type:
assay_interference
Nature:
absolute
Temporal spacing:
null
Description:
Metabolites of levodopa can react with the reagents on urine test strips, potentially causing a false-positive result for ketones.
Actionable advice:
Inform the laboratory or your doctor that you are taking levodopa if you are having your urine tested for ketones.
Target id:
/biomarker/comprehensive-metabolic-panel
Target name:
Comprehensive Metabolic Panel
Severity:
minor
Interaction type:
assay_interference
Nature:
absolute
Temporal spacing:
null
Description:
Levodopa can interfere with colorimetric laboratory tests, potentially causing falsely elevated or decreased values for creatinine, uric acid, and glucose.
Actionable advice:
Inform the laboratory that you are taking levodopa when providing samples for metabolic panels.