Domperidone

Domperidone is a drug used to treat various gastrointestinal disorders. It belongs to a group of drugs called dopamine antagonists. Domperidone is commonly used to reduce nausea and vomiting and to improve digestion.

Domperidone is available in a variety of forms, including tablets and oral suspensions.

It is important to consult with your doctor before starting domperidone to obtain individualized recommendations on dosage and administration, as well as to assess the risk of possible side effects.

Indications Domperidone

1. Nausea and vomiting: Domperidone is used to treat nausea and vomiting, which can be caused by a variety of reasons, including infections, food poisoning, medications, radiation therapy, and chemotherapy.
2. Gastroparesis: This is a condition in which the muscles in the stomach do not work properly, which slows down the passage of food through the gastrointestinal tract and can cause nausea, vomiting, and other symptoms. Domperidone can be used to treat gastroparesis.
3. Reflux oesophagitis: Domperidone may be used to treat reflux oesophagitis, a condition in which acid from the stomach rises up into the oesophagus, causing irritation and inflammation.
4. Other gastrointestinal disorders: Domperidone may be used to treat other gastrointestinal disorders such as functional gastrointestinal disorders, constipation and diarrhea.

Release form

1. Oral tablets: This is the most common form of domperidone, available in both regular and disintegrating tablets. Tablets can contain different amounts of the active ingredient, usually between 10 mg and 20 mg.
2. Oral suspension: A liquid form of domperidone that is convenient for children and adults who have difficulty swallowing tablets. The suspension allows for easy dosage adjustment.

Pharmacodynamics

Its pharmacodynamics are related to its ability to block dopamine receptors in the body.

Domperidone is a dopamine D2 receptor antagonist. It acts primarily in the small intestine and results in increased peristalsis and faster gastric emptying. This explains its effectiveness in treating nausea and vomiting.

Blocking dopamine receptors also results in a decrease in the inhibition of dopamine antagonist on prolactin, which may increase its blood levels. In this regard, domperidone may also be used to stimulate lactation in women.

In general, the pharmacodynamics of domperidone are related to its ability to increase gastrointestinal motility and reduce nausea and vomiting by blocking dopamine receptors.

Pharmacokinetics

1. Absorption: Domperidone is generally well absorbed from the gastrointestinal tract when administered orally. It has high bioavailability.
2. Distribution: Domperidone has a relatively low volume of distribution, meaning that it is distributed primarily into body fluids rather than tissues.
3. Plasma protein binding: Approximately 90% of domperidone is bound to plasma proteins.
4. Metabolism: Domperidone is metabolized in the liver, primarily by the enzyme CYP3A4. Its metabolites do not have pharmacological activity.
5. Elimination: About 30-40% of domperidone is excreted unchanged via the kidneys, and the remainder via the intestines. The half-life is about 7-9 hours.
6. Effect on other drugs: Domperidone may interact with drugs that are also metabolized by the CYP3A4 enzyme, which may lead to an increase or decrease in their blood levels.
7. Food and Antacids: Food and antacids containing aluminum or magnesium may delay the absorption of domperidone from the gastrointestinal tract.
8. Pharmacokinetics in different populations: In elderly patients and in patients with impaired renal function, the pharmacokinetic parameters of domperidone may be altered.

Dosing and administration

For adults and children over 12 years old (or weighing more than 35 kg):

• Oral administration: The usual dose is 10 mg 15-30 minutes before meals and, if necessary, at bedtime. Domperidone can be taken up to 3-4 times a day, the maximum daily dose should not exceed 80 mg.

For children under 12 years old:

• The use of domperidone in children under 12 years of age (or weighing less than 35 kg) should be limited and closely monitored by a physician because of potential risks and side effects.
• Rectal suppositories can be used for children, but the dosage and frequency of use should be carefully determined by the doctor.

For patients with renal insufficiency:

• Patients with impaired renal function may require dosage adjustments and longer intervals between doses. It is important to consult a physician to determine a safe dosage.

Special instructions:

• Domperidone should be taken 15-30 minutes before meals for maximum effectiveness, as food may slow its absorption and reduce its effectiveness.
• If you miss a dose, take the missed dose as soon as possible, but if it is almost time for your next dose, skip it and continue your dosing schedule. Do not double the next dose to make up for the missed one.

Use Domperidone during pregnancy

Use of Domperidone during pregnancy requires caution as there is limited data on its safety during pregnancy. The following are the main findings from the available studies:

1. A study of pregnancy outcomes with domperidone showed that use of the drug in the first trimester of pregnancy was not associated with an increased risk of spontaneous abortion, stillbirth, major birth defects, preterm birth, or low birth weight. However, additional studies are needed to confirm these findings in a larger sample (Pasternak et al., 2013).
2. EFEMERIS database: Another study conducted within the EFEMERIS database compared pregnancy outcomes in women exposed to domperidone and those not exposed to the drug. The findings indicated no significant difference in the incidence of birth defects between the groups, further highlighting the potential safety of the drug during pregnancy (Araujo et al., 2021).

Before using domperidone or other medications during pregnancy, you should consult your doctor to evaluate all possible risks and benefits.

Contraindications

1. Allergic reaction: People with a known allergy to domperidone or any other ingredient in the drug should avoid using it.
2. Heart problems: Domperidone may worsen heart problems or arrhythmia, so it is generally not recommended for patients with heart failure or other heart conditions.
3. Intestinal problems: People with intestinal bleeding, perforation, or mechanical obstruction in the stomach or intestines should avoid using domperidone.
4. Liver problems: Domperidone should be used with caution in patients with severe liver dysfunction or liver failure, as it may increase adverse effects.
5. Kidney problems: People with severe kidney problems or kidney failure may have limited use of domperidone.
6. Electrolyte problems: Because of its effects on the gastrointestinal tract, domperidone may affect electrolyte levels in the body. People with electrolyte imbalances should be careful when using the drug.

Side effects Domperidone

1. Drowsiness: Some patients may experience drowsiness or tiredness while taking domperidone.
2. Dizziness: This can also be a common side effect of domperidone.
3. Dry mouth: Some people may experience a feeling of dry mouth after taking domperidone.
4. Abdominal pain: Some patients may experience pain or discomfort in the abdominal area.
5. Constipation: Some patients may experience constipation after taking domperidone.
6. Menstrual Cycle Problems: Women may experience irregularities in their menstrual cycle.
7. Milky discharge from the breasts: Some women, especially after childbirth, may experience milky discharge from the breasts.
8. Extrapyramidal symptoms: In rare cases, extrapyramidal symptoms such as tremors, unusual body movements, or muscle cramps may occur with the use of domperidone.

Overdose

1. Dizziness and drowsiness.
2. Insomnia or other sleep disorders.
3. Restlessness or irritability.
4. Involuntary movements, such as shaking or unusual body movements (dyskenesia).
5. Tachycardia (rapid heart rate).
6. Cramps.
7. Unusual changes on the electrocardiogram (ECG).

Interactions with other drugs

1. Drugs that prolong the QT interval: Domperidone may increase the prolongation of the QT interval on the ECG. Concomitant use with other drugs such as antiarrhythmic drugs (eg, amidaron, sotalol) or antiarrhythmic antibiotics (eg, erythromycin, clarithromycin) may increase the risk of cardiac arrhythmias.
2. Central nervous system depressants: Concomitant use with other drugs such as benzodiazepines, narcotic analgesics or hypnotics may enhance their sedative effect.
3. Drugs that enhance the effect of anticholinergic drugs: Concomitant use with anticholinergic drugs such as antihistamines or antispasmodics may enhance the anticholinergic effects of domperidone.
4. Drugs that enhance the antidopaminergic effect: Concomitant use with other antidopaminergic drugs, such as some antipsychotics or antiparkinsonian drugs, may enhance their effect and lead to increased side effects.
5. Drugs that alter gastric acidity: Drugs that reduce gastric acidity, such as antacids or proton pump inhibitors, may slow the absorption of domperidone from the gastrointestinal tract.
6. Drugs that increase the risk of extrapyramidal symptoms: Concomitant use with certain drugs, such as neuroleptics, may increase the risk of developing extrapyramidal symptoms.