Kava and Metoclopramide Injection: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Kava
No brand names on recordMetoclopramide Injection
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
Additive DOPamine antagonist effects
Interaction Deep Dive
Theoretically, kava may add to the effect of DOPamine antagonists, increasing the risk for adverse effects. Case reports describe what appears to be DOPamine-blocking activity of kava manifested in patients as dystonia, dyskinesias, and Parkinsonism12. Kava extracts antagonized apomorphine-induced hyperreactivity to external stimuli in mice, suggesting DOPamine blockade activity 3.
Why it happens (mechanism)
DOPamine antagonist effect of kava
Literature reports
5 reports — tap to read
a) A 27-year-old Aboriginal Australian male presented three times following heavy kava use with symptoms of severe choreoathetosis of the limbs, trunk, neck, and facial musculature, and athetosis of the tongue. Level of consciousness was not impaired. Symptoms resolved within 12 hours of intravenous diazepam on each occasion. Acute rheumatic fever was excluded, cerebrospinal fluid and computed tomography of the brain was normal, and urinary drug screen was negative. The only abnormalities found in hematological and biochemical tests were a serum alkaline phosphatase of 162 international units/L (normal: 35 to 135 international units/L) and serum gamma-glutamyltransferase of 426 international units/L (normal less than 60 international units/L). These were attributed to kava use. The patient did not drink alcohol 1.
b) A 76-year-old female with idiopathic Parkinson's disease of 17 years' duration treated for 8 years with levodopa 500 mg and benserazide 125 mg was prescribed kava extract (Kavasporal Forte(R)) 150 mg twice daily for complaints of inner tension. Within 10 days, she noted a pronounced increase in her daily "off" periods both in terms of duration and number. Within 2 days of discontinuing the kava product, symptoms had returned to her normal baseline 2.
c) A 63-year-old female experienced sudden and acute forceful involuntary oral and lingual dyskinesias on the fourth day of self-initiated therapy with kava extract (Kavasporal Forte(R)) 150 mg three times daily. She was treated successfully in the emergency room with biperiden 5 mg intravenously. She denied taking any other medications in the months preceding this event 2.
d) A 22-year-old female took kava extract (Laitan(R)) 100 mg once for anxiety and nervousness. Within four hours she experienced oral and lingual dyskinesias, tonic rotation of the head, and painful twisting trunk movements. She was treated successfully with biperiden 2.5 mg intravenously. She denied taking any other medications in the months preceding this event 2.
e) A 28-year-old male experienced acute involuntary neck extension with forceful upward deviation of the eyes within 90 minutes of taking kava extract (Laitan(R)) 100 mg. Symptoms resolved spontaneously within 40 minutes. This man had a history of acute dystonic reactions following exposure to promethacin (50 mg) and fluspirilene (1.5 mg), which had responded biperiden 5 mg intravenously 9 and 12 years previously 2.
Common questions
Can I take Kava and Metoclopramide Injection together?
Additive DOPamine antagonist effects Always confirm with your pharmacist or prescriber before making any change.
How serious is the Kava and Metoclopramide Injection interaction?
It is rated moderate. Can be significant — usually manageable with monitoring.
How quickly could this interaction happen?
The documented onset is "rapid". Effects can appear quickly, often within about 24 hours of combining the drugs.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Kava or Metoclopramide Injection need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there anything you'd monitor while I'm on both?
References (3)
- Spillane PK, Fisher DA, & Currie BJ: Neurological manifestations of kava intoxication. Med J Australia 1997; 167(3):172-173. DOI
- Schelosky L, Raffauf C, Jendroska K, et al: Kava and dopamine antagonism. J Neurol Neurosurg Psych 1995; 58(5):639-640. PubMed
- Jamieson DD, Duffield PH, Cheng D, et al: Comparison of the central nervous system activity of the aqueous and lipid extract of kava (Piper methysticum). Arch Int Pharmacodyn Ther 1989; 301:66-80.
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