Costi still works, but often less dramatically when:
- The mother is pumping for a sick or premature baby but has not managed to develop a full milk supply.
- The mother is trying to develop a full milk supply while nursing an adopted baby.
- The mother is trying to wean the baby from supplements.
- Costi is now restricted to use in the relief of nausea and vomiting
- It should be used at the lowest effective dose for the shortest possible time
Are there long-term concerns about the use of Costi?
The manufacturer states in its literature that chronic treatment with Costi in rodents has resulted in increased numbers of breast tumours in the rodents. The literature goes on to state that this has never been documented in humans. Note that toxicity studies of medication usually require treatment with huge doses over periods of time involving most or all of the animal’s lifetime. Note also that not breastfeeding increases the risk of breast cancer, and breast cancer risk decreases the longer you breastfeed.
Can Costi cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common ones associated with Costi. You will find a full list in the manufacturer's information leaflet supplied with your medicine. Speak with your doctor or pharmacist if any of the following become troublesome.
Costi , metoclopramide, and prochlorperazine are not significantly renally cleared and can be used in CKD; however, extrapyramidal and CNS effects may be more prevalent, especially in high dose. Dosing should be cautiously titrated to effect. Costi does not cross the blood-brain barrier and may be preferable for long-term management. Metoclopramide and Costi increase gastric emptying, which may alter drug pharmacokinetics.
Other DA Antagonists
Metoclopram >Costi are potent D-2 DA antagonists which, like the antipsychotics, stimulate PRL secretion . Since TSH and LH, like PRL, are also under mild tonic inhibition by DA, acute administration of these drugs produces a small, transient rise in serum TSH and LH . Chronic endocrine effects are similar to those of the antipsychotics . Acutely, metoclopramide, but not sulpiride, Costi, or haloperidol, stimulates vasopressin secretion .
Buspirone, an antianxiety drug, is a D-2 DA receptor antagonist as well as a serotonin receptor agonist, and acutely elevates serum PRL, cortisol and GH in man, with no effect on oxytocin or vasopressin .
When is it appropriate to use Costi?
Costi must never be used as the first approach to correcting breastfeeding difficulties. Costi is not a cure for all things. It must not be used unless all other factors that may result in insufficient milk supply have been dealt with first. What can be done?
- Correct the baby’s latch so that the baby can obtain as efficiently as possible the milk that the mother has available. Correcting the latch may be all that is necessary to change a situation of “not enough milk” to one of “plenty of milk”.
- Use breast compression to increase the intake of milk.
- Use milk expression after feedings to increase the supply.
- Correct sucking problems by stopping the use of artificial nipples (Using a Lactation Aid, and Finger Feeding) and other stratagems.
Mechanism of action and clinical use
Costi , metoclopramide and the antipsychotic drugs are antagonists at dopamine D 2 receptors and inhibit dopaminergic stimulation of the CTZ (see Fig. 32.1 ). Anti-emetic doses of antipsychotic drugs are generally less than one third of those used to treat psychoses. The pharmacology of the antipsychotic drugs is discussed in Chapter 21 .
Costi acts solely by dopamine receptor blockade and does not readily cross the blood–brain barrier. Metoclopramide is a dopamine receptor antagonist at usual oral doses but also acts as a 5-HT3 receptor antagonist at higher doses. Metoclopramide also has prokinetic actions on the gut due to agonist activity at the 5-HT4 receptor subtype in the enteric nervous system. It increases tone in the gastro-oesophageal sphincter and enhances both gastric emptying and small intestinal motility.
Dopamine receptor antagonists are mainly used to reduce vomiting induced by radiotherapy, drugs and surgery. The dual-receptor action of metoclopramide gives enhanced efficacy; it is used at high doses intravenously to treat delayed vomiting induced by emetogenic cytotoxic agents such as cisplatin. Levomepromazine is used to relieve vomiting in palliative care. Costi and metoclopramide are ineffective for vomiting arising from stimulation of the vestibular system. Antipsychotic drugs such as prochlorperazine are effective for vestibular disorders and motion sickness owing to their antimuscarinic activity.