From the Guidelines
Side Effects of Domperidone
Domperidone is associated with cardiac side effects, including QT prolongation and ventricular tachycardia, as its most significant risks 1.
- The medication does not readily cross the blood-brain barrier, which results in fewer central side effects compared to metoclopramide, such as somnolence, depression, hallucinations, and extrapyramidal symptoms 1.
- However, cardiac monitoring is recommended for patients on long-term domperidone due to the risk of QTc prolongation 1.
- A study of 115 gastroparesis patients found that 7% had cardiac side effects requiring drug cessation 1.
- The risk of torsade de pointes tachycardia is also a concern, particularly with intravenous bolus doses, but the risk with oral therapeutic doses appears to be low 1.
- Other side effects may include diarrhea and gastrointestinal disturbances, but these are less commonly reported compared to cardiac effects.
- It is essential to weigh the benefits of domperidone against its potential risks, especially in patients with pre-existing cardiac conditions or those taking other medications that may interact with domperidone 1.
From the FDA Drug Label
The safety of EQUIDONE Gel has not been evaluated in breeding, pregnant and lactating mares other than in the last 45 days of pregnancy and the first 15 days of lactation Do not use in horses with suspected or confirmed gastrointestinal blockage, as domperidone is a prokinetic drug (it stimulates gut motility). Use of EQUIDONE Gel may cause a false positive on the milk calcium test used to predict foaling. Significant inhibition of domperidone metabolism may occur when co-administered with drugs such as erythromycin and ketoconazole. The side effects of Domperidone include:
- Gastrointestinal blockage (contraindication)
- False positive on the milk calcium test used to predict foaling
- Potential increased drug exposure when co-administered with certain drugs, such as erythromycin and ketoconazole, due to CYP3A4 inhibition 2
From the Research
Side Effects of Domperidone
The side effects of domperidone have been reported in several studies, including:
- Headache, tachycardia/palpitations, and diarrhea were the most common side effects reported by 44 patients in a study of 115 patients treated with domperidone for gastroparesis 3
- Genetic polymorphism in the KCNH2 gene was associated with effectiveness of domperidone, while polymorphism in the ABCB1 gene was associated with the efficacious dose 4
- Side effects were seldom reported with therapeutic doses of domperidone, and the drug did not aggravate extrapyramidal side effects of neuroleptic drugs 5
- Domperidone may cause QT prolongation and is associated with increased risk of ventricular tachyarrhythmia and sudden cardiac death, particularly when co-administered with QT-interacting medications 6, 7
- Other reported side effects of domperidone include nausea, vomiting, and stomach fullness, although these symptoms were also improved in many patients treated with the drug 3, 5
Factors Influencing Side Effects
Several factors may influence the occurrence of side effects with domperidone, including:
- Age: older patients may be more likely to experience benefits from domperidone, but may also be at increased risk of side effects 4
- Genetic polymorphisms: certain genetic variations may affect the response to domperidone and the risk of side effects 4
- Co-administration of other medications: QT-interacting medications may increase the risk of cardiac side effects with domperidone 6, 7
- Underlying medical conditions: patients with pre-existing cardiac disease may be at increased risk of side effects with domperidone 7