From Rang & Dale's Pharmacology, 9th edition (2020), page 401-403:
Metoclopramide [...] produces a number of unwanted effects including disorders of movement (more common in children and young adults), fatigue, motor restlessness, spasmodic torticollis (involuntary twisting of the neck) and oculogyric crises (involuntary upward eye movements). It stimulates prolactin release [...] causing galactorrhoea and disorders of menstruation.
Domperidone is a similar drug used to treat vomiting [...]. Unlike metoclopramide, it [is] less prone to producing central side effects. However, domperidone is associated with a small increased risk of serious cardiac adverse effects (particularly at higher doses and in older patients), and its use is now restricted.
Both drugs are given orally, have plasma half-lives of 4–5 h and are excreted in the urine.
Clinical use of antiemetic drugs:
– Metoclopramide: vomiting caused by migraine, radiation, gastrointestinal disorders, cytotoxic drugs, prevention of nausea and vomiting in the postoperative period.
– Domperidone is less liable to cause central nervous system side effects [...].
– Cyclizine: motion sickness, vestibular disorders, nausea and vomiting associated with surgery and postoperative narcotic analgesic use.
Is cyclizine ineffective?
Cinnarizine,
cyclizine and promethazine are the most commonly [anti-emetic drugs] employed; they are effective against nausea and vomiting arising from many causes, including motion sickness and the presence of irritants in the stomach. None is very effective against substances that act directly on the CTZ [Chemoreceptor Trigger Zone]. Promethazine is used for morning sickness of pregnancy (on the rare occasions when this is so severe that drug treatment is justified), and has been used by NASA to treat space motion sickness. Drowsiness and sedation, while possibly contributing to their clinical efficacy, are the chief unwanted effects. Betahistine [...] is used to control the nausea and vertigo associated with Menière's disease.
I hope that helps...