Domperidone is consider as a potent dopamine D2 antagonist, chemically related to haloperidol, but pharmacologically related to metoclopramide. Domperidone does not cross blood brain barrier. Accordingly, extra pyramidal side effects are rare, antiemetic efficacy is lower than Metoclopramide. Cholinergic action in GIT promotes gastric emptying.
Domperidone helps to move food faster through the oesophagus, stomach and intestines so that it does not stay for too long in the same place or flow backwards.
Domperidone is well absorbed orally, with bioavailability of only 15%, this low value is due to an extensive first-pass metabolism in the gut wall and liver. The peak plasma concentration is achieved at 30 to 60 minutes.
After rectal administration, peak plasma levels are only about one third of that of an oral dose, the mean rectal bioavailability of 12.4% is quite similar to that after oral administration.
The percentage bound of Domperidone to plasma proteins is 91-93%. Distribution studies have shown wide tissue distribution, but low brain concentration. Domperidone undergoes rapid and extensive hepatic metabolism by and N-dealkylation by CYP3A4 the major form of cytochrome P-450 and by hydroxylation by CYP3A4, CYP1A2 and CYP2E1.
Domperidone is excreted urinary and faecal amount to 31% and 66% of the oral dose, respectively. The proportion of the drug excreted unchanged is small. The plasma half-life is 7-9 hours in healthy subjects but is prolonged in patients with severe renal insufficiency.
Motabar are used to the short-term symptoms of nausea, vomiting.
Treating the feeling of fullness during or shortly after a meal, and backflow of the stomach contents to the oesophagus.
- Hypersensitivity to domperidone or any of the other ingredients.
- Prolactin-releasing pituitary tumour (prolactinoma).
- Patients with gastrointestinal hemorrhage, mechanical obstruction or perforation.
Like all medicament Motabar can have side-effects. Tell your doctor or pharmacist, immediately, if you notice any of the following:
- Galactorrhoea or gynaecomastia.
- Disorders of the nervous system: abnormal muscle movements or tremor (shaking) can occur. The risk of abnormal muscle movements is greatest in the newborn babies, infants and young children.
- Disorders of the immune system: allergic reactions (e.g. skin rash, itching, shortness of breath, wheezing and/or swollen face).
- Disorders of the cardiovascular system: very rare heart rhythm disorders have been reported.
- Reducing libido.
Warnings and Precautions:
Since Domperidone is highly metabolised in the liver, Motabar should not be used in patients with hepatic impairment.
Caution in patients with severe renal impairment (serum creatinine > 6 mg/100 ml) the elimination half-life of domperidone was increased from 7.4 to 20.8 hours, but plasma drug levels were lower than in healthy volunteers. It is unlikely that the dose of a single administration needs to be adjusted in patients with renal insufficiency. However, on repeated administration, the dosing frequency should be reduced to once or twice daily depending on the severity of the impairment, and the dose may need to be reduced.
Domperidone is not recommended for chronic use or for the routine prophylaxis of postoperative nausea and vomiting.
Should be given with caution to children due to the risk of extrapyramidal effects.
Domperidone is mainly metabolized by cytochrome CYP3A4, and concomitant administration of domperidone with the inhibitors of this enzyme (ketoconazole or oral erythromycin) can lead to increases its plasma concentrations. Both the Cmax and AUC of domperidone were increased approximately three-fold in these interaction studies.
There is a theoretical potential that domperidone may antagonize the hypoprolactinaemic effect of drugs such as Bromocriptine. In addition, prokinetic effects of domperidone may alter the absorption of some drugs. Opioid analgesics and antimuscarinics may antagonize the prokinetic effects of domperidone.
Pregnancy and lactation:
There is some data after marketing about the use of domperidone in pregnant women. A study in rats have shown a reproductive toxic effect with high doses, it is toxic for the mother. MOTABAR should not be used during pregnancy; except if the therapeutic benefit to the mother outweighs the possible effect on the fetus.
Small amount of domperidone are distributed into breast milk, reaching concentrations about one-quarter of those in maternal serum, and the toxicity for the neonates is not known, so MOTABAR should not be used during lactation.
Symptoms of overdose may include drowsiness, disorientation and extrapyramidal reactions, especially in children. There is no specific antidote to domperidone, but in the event of overdose, gastric lavage, as well as the administration of activated charcoal, may be useful. Close medical supervision and supportive therapy is recommended. Anticholinergic, anti-parkinson drugs may be helpful in controlling the extrapyramidal reactions.
Dosage and Administration:
Motabar should be taken before meal 15-30 minutes.
The initial duration of treatment is four weeks, Patients should be re-evaluated after four weeks and the need for continued treatment re-assessed.
Adults: (weighing 35 kg or more)
1-2 tablets (10 mg), 3-4 times daily (the maximum daily dose is 80 mg).
0.2- 0.4 mg/Kg (0.2 – 0.4 mL of the oral drop for 1 kg) of body weight, repeated every 4-8 hours.
Store at room temperature below 25°C. Keep container in the outer carton to protect from light. Do not refrigerate or freeze.
Motabar F.C. Tablets: Box of 20 Tablets, each F.C. Tablet contains 10 mg Domperidone.
Motabar Oral Suspension: A glass bottle of 100 ml, each 5ml contains 5 mg Domperidone.
Motabar Drops Suspension: A glass bottle of 15 ml, or 30 ml, each 1ml contains 1mg Domperidone.
Do not use the drug after the expiry date printed on the carton package.