From the Guidelines
Metoclopramide use is associated with serious adverse effects, including extrapyramidal signs such as acute dystonic reactions, drug-induced parkinsonism, akathisia, and tardive dyskinesia, and its use should be limited to severe cases of gastroparesis that are unresponsive to other therapies and for no more than 12 weeks. The side effects of metoclopramide are a major concern, particularly the risk of movement disorders, which can be irreversible in some cases 1. These extrapyramidal symptoms occur because metoclopramide blocks dopamine receptors in the brain. Other common side effects include:
- Drowsiness
- Fatigue
- Restlessness
- Diarrhea
- Headache Some patients may also experience:
- Depression
- Anxiety
- Insomnia
- Hyperprolactinemia, which may lead to galactorrhea, gynecomastia, or menstrual irregularities. The risk of side effects increases with higher doses and longer duration of treatment, which is why the FDA recommends limiting metoclopramide use to no more than 12 weeks 1. Elderly patients, children, and those with renal impairment are at higher risk for adverse effects and should receive lower doses. If extrapyramidal symptoms occur, treatment should be discontinued immediately, and diphenhydramine 25-50mg can be administered for acute dystonic reactions. Given the potential risks, metoclopramide should be reserved for severe cases of gastroparesis that are unresponsive to other therapies, such as domperidone or erythromycin 1.
From the FDA Drug Label
Metoclopramide can cause serious side effects, including:
- Abnormal muscle movements.
- Uncontrolled spasms of your face and neck muscles, or muscles of your body, arms, and legs (dystonia).
- Depression, thoughts about suicide, and suicide
- Neuroleptic Malignant Syndrome (NMS).
- Parkinsonism. Common side effects of metoclopramide include:
- feeling restless, sleepy, tired, dizzy, or exhausted
- headache
- confusion
- trouble sleeping
The possible side effects of Metoclopramide include:
- Serious side effects:
- Abnormal muscle movements
- Dystonia
- Depression, thoughts about suicide, and suicide
- Neuroleptic Malignant Syndrome (NMS)
- Parkinsonism
- Common side effects:
From the Research
Metoclopramide Side Effects
- Metoclopramide is a dopamine receptor antagonist used to treat gastroparesis, and its side effects have been studied in various research papers 4, 5, 6, 7, 8.
- The risk of tardive dyskinesia, a serious side effect of metoclopramide, has been estimated to be low, around 0.1% per 1000 patient years 5.
- High-risk groups for tardive dyskinesia include elderly females, diabetics, patients with liver or kidney failure, and patients with concomitant antipsychotic drug therapy 5.
- Other side effects of metoclopramide include extrapyramidal side effects, which can be reduced by administering the drug as a continuous intravenous infusion rather than a bolus infusion 8.
- The incidence of side effects to metoclopramide has been associated with polymorphisms in certain genes, such as CYP2D6, KCNH2, and HTR4 6.
- Clinical parameters, such as age, sex, weight, and diabetic status, can also influence the response to metoclopramide and the occurrence of side effects 6.
Factors Influencing Side Effects
- Pharmacogenetic parameters, such as polymorphisms in the CYP2D6 gene, can affect the metabolism of metoclopramide and increase the risk of side effects 6, 7.
- The dose and duration of metoclopramide treatment can also influence the risk of side effects, with higher doses and longer treatment durations increasing the risk of tardive dyskinesia 5, 7.
- Concomitant use of other medications, such as antipsychotics, can also increase the risk of side effects when taking metoclopramide 5, 8.
Administration and Side Effects
- The method of administration of metoclopramide, such as continuous intravenous infusion versus bolus infusion, can affect the incidence of extrapyramidal side effects 8.
- Continuous intravenous infusion of metoclopramide has been shown to reduce the appearance of extrapyramidal side effects compared to bolus administration 8.