Domegan

Domegan is a trade name for a drug whose main active ingredient is ondansetron. Ondansetron belongs to a class of drugs called serotonin 5-HT3 receptor antagonists. It is used to prevent nausea and vomiting caused by various factors.

Ondansetron is often used in the following situations:

1. Chemotherapy: The drug is used to prevent nausea and vomiting that may occur as a result of chemotherapy treatment.
2. Radiotherapy: It can also be used to reduce nausea and vomiting caused by radiotherapy.
3. After surgery: Ondansetron can be used to prevent nausea and vomiting after surgery.
4. Medication: Ondansetron is sometimes used to treat nausea and vomiting caused by medications or other drugs.

Ondansetron is available in  injection solution form.

Before use, it is important to consult with your doctor to determine the best dosage and form of the drug for your individual needs and taking into account the specifics of your disease or treatment.

Indications Domegan

1. Chemotherapy: Domegan is used to prevent nausea and vomiting, which patients often experience during chemotherapy treatment.
2. Radiotherapy: It can also be used to reduce nausea and vomiting caused by radiotherapy.
3. Postoperative nausea and vomiting: Domegan can be used to prevent and treat nausea and vomiting after surgery.
4. Drug therapy: It is sometimes used to treat nausea and vomiting caused by other medications.
5. Gastroenterological disorders: Domegan can be used for various gastroenterological disorders, such as gastritis, gastroesophageal reflux (GERD), gastroenteritis, etc., if accompanied by nausea and vomiting.

Release form

Injection solution: Ondansetron solution is used for intravenous and sometimes intramuscular administration. This form is preferred in conditions where a quick effect is needed, for example, to prevent nausea and vomiting after surgery or during chemotherapy.

Pharmacodynamics

Its pharmacodynamics involve interaction with certain receptors in the body, which helps reduce stimulation of the vomiting centers in the brain.

Domegan belongs to a class of drugs known as selective 5-hydroxytryptamine (5-HT3) antagonists. These drugs act on serotonin receptors (5-HT3), unlike other serotonin antagonists. Ondansetron blocks the action of serotonin at peripheral and central 5-HT3 receptors.

Ondansetron acts primarily in the small intestine and at the brain level, where it reduces activation of vomiting centers in the brain, such as the vomit center nuclei. This results in a reduction in nausea and vomiting associated with chemotherapy or postoperative conditions.

This mechanism of action makes Domperidone an effective treatment for nausea and vomiting in a variety of clinical situations.

Pharmacokinetics

1. Absorption: Ondansetron is usually well absorbed after oral administration. Maximum plasma concentration is usually achieved 1-2 hours after administration.
2. Distribution: Ondansetron has a large volume of distribution, indicating its distribution into many tissues of the body. It can cross the placental barrier and is found in breast milk.
3. Plasma protein binding: Ondansetron binds to plasma proteins in a small amount, approximately 70-76%.
4. Metabolism: Ondansetron is metabolized in the liver to form several metabolites, including hydroxy-ondansetron and glucuronides. The main route of metabolism is oxidation through cytochrome P450 enzymes, predominantly CYP3A4 and CYP1A2.
5. Elimination: Ondansetron is eliminated from the body primarily through the kidneys. The elimination half-life is approximately 4-6 hours in adults and may be prolonged in elderly patients or those with impaired renal function.

Dosing and administration

For Adults:

For chemotherapy with a high risk of causing vomiting:

• Oral: The usual starting dose is 24 mg 30 minutes before chemotherapy.
• Intravenous: 0.15 mg/kg, usually three doses, the first given 30 minutes before chemotherapy, with subsequent doses given 4 and 8 hours after the first dose.

For chemotherapy with a low or moderate risk of causing vomiting:

• Oral: 8 mg 30 minutes before chemotherapy, then 8 mg every 12 hours for 1 to 2 days after chemotherapy.
• Intravenous: 0.15 mg/kg up to three times daily.

Postoperative nausea and vomiting:

• Oral: 16 mg 1 hour before anesthesia.
• Intravenous: 4 mg immediately before anesthesia.

For children:

With chemotherapy:

• Intravenous: 0.15 mg/kg, maximum three doses, the first administered 30 minutes before chemotherapy, the next - 4 and 8 hours after the first.
• Oral: Dosage may vary, but is usually 4 mg 30 minutes before chemotherapy, then doses 4 and 8 hours after the first dose.

Postoperative nausea and vomiting:

• Intravenous or oral: Doses and method of administration are similar to adults, but take into account the child's weight and clinical needs.

General recommendations:

• Ondansetron can be taken with or without food.
• It is necessary to monitor the patient's hydration, especially if there is severe vomiting.
• The dosage can be adjusted depending on the individual response of the patient and on the recommendation of the doctor.

Use Domegan during pregnancy

The use of Domegan during pregnancy may be associated with some risks, so its use requires caution. Key findings from scientific research:

1. Ondansetron and the Risk of Adverse Fetal Outcomes: A Danish study found that taking ondansetron during pregnancy is not associated with an increased risk of spontaneous abortion, stillbirth, major birth defects, preterm birth, or low birth weight or small for gestational age babies. This study provides encouraging data that ondansetron may be safe for use during pregnancy (Pasternak et al., 2013).
2. Western Australia Study: The study found that ondansetron was prescribed to pregnant women to treat morning sickness and vomiting, and although there was no significant increase in the risk of major birth defects with exposure in the first trimester, the study could not definitively conclude that ondansetron is safe for use during pregnancy (Colvin et al., 2013).

Overall, these studies suggest that ondansetron can be used during pregnancy if clinically appropriate and the potential benefits outweigh the potential risks.

Contraindications

1. Allergy to ondansetron or any other component of the drug. Patients with known hypersensitivity to ondansetron or related substances (eg, granisetron) should avoid using this drug.
2. Concomitant use with apomorphine. Ondansetron should not be used together with apomorphine, as this combination may cause a significant decrease in blood pressure and loss of consciousness.
3. Patients with cardiac conduction disorders, such as congenital or acquired long QT interval. Ondansetron may prolong the QT interval, which increases the risk of serious arrhythmias.
4. Severe forms of liver failure. Ondansetron is metabolized by the liver, and its use in patients with severe hepatic impairment may result in drug accumulation and an increased risk of side effects.

Ondansetron should be used with caution in patients with:

• Chronic heart disease, especially if there are risk factors for prolongation of the QT interval.
• Electrolyte imbalance, as this may affect the risk of QT interval prolongation.

Side effects Domegan

1. Headache: This is one of the most common side effects associated with ondansetron.
2. Drowsiness: Some people may feel drowsy or tired while taking this drug.
3. Constipation or diarrhea: Some patients may experience gastrointestinal problems such as constipation or diarrhea.
4. Dizziness: This side effect may occur in some patients when taking Domegan.
5. Muscle weakness: Rare, but some people may experience muscle weakness while using the drug.
6. Depression or mood changes: Some people may experience depression, anxiety, or other mood changes.
7. Allergic reactions: In rare cases, an allergic reaction may occur, which may include skin rash, itching, swelling of the face, or difficulty breathing.
8. Extrapyramidal symptoms: These symptoms include shaking, stomach cramps, or unusual body movements that may occur with ondansetron, especially in children.

Overdose

An overdose of Dogansetron (ondansetron) can cause a variety of symptoms and complications, including increased side effects such as dizziness, headache, drowsiness, increased heart rate (tachycardia), changes in the electrocardiogram (ECG), possibly even cardiac arrhythmias.

Interactions with other drugs

1. Drugs that prolong the QT interval: Ondansetron may potentiate a prolonged QT interval on the ECG. Concomitant use with other drugs, such as antiarrhythmic drugs (eg, amidarone, sotalol) or antiarrhythmic antibiotics (eg, erythromycin, clarithromycin), may increase the risk of cardiac arrhythmias.
2. Serotonergic drugs: Concomitant use of ondansetron with other serotonergic drugs, such as selective serotonin reuptake inhibitors (SSRIs) or triptans, may increase the risk of developing serotonin syndrome.
3. Drugs that enhance anticholinergic effects: Concomitant use with drugs that have anticholinergic properties, such as antihistamines, some antispasmodics and antidepressants, may enhance the anticholinergic effects of ondansetron.
4. Drugs that increase the risk of hypertension: Ondansetron may increase the risk of hypertensive crisis when used together with monoamine oxidase inhibitors (MAOIs), certain antidepressants, or serotonin synthesizers.
5. Drugs that increase the effects of sedation or decreased reflexes: Concomitant use of ondansetron with drugs such as benzodiazepines, hypnotics or alcohol may increase their sedative effect.