Domperidone Apomorphine

Rescue with a dopamine agonist (apomorphine) given with domperidone or trimethobenzamide... 

Domperidone [133], one of the most potent D2-dopamine blockers and antagonists of apomorphine-induced emesis with limited brain-blood barrier permeability, did not establish a position as an antiemetic, especially against cisplatin [134], Recently, the use of domperidone as a parenteral antiemetic has been discontinued because of serious cardiovascular toxicity. 

Apomorphine is a potent dopamine agonist, which is sometimes useful in advanced Parkinson s disease for patients with severe unpredictable off periods on treatment. It is only available as a subcutaneous injection or infusion and thus requires significant patient and/or carer involvement in treatment. It is highly emetogenic so patients must receive domperidone, starting at least 2 days before apomorphine treatment. 

Apomorphine is a potent dopamine receptor agonist used in advanced disease. It has to be administered by subcutaneous injection and causes such severe nausea and vomiting that an antiemetic (domperidone) has to be administered for two days prior to treatment. 

The hypotensive adverse effects of apomorphine may possibly be increased by alcohol. The concurrent use of other drugs used for erectile dysfunction or dopamine agonists or antagonists is not recommended. However, domperidone, and prochlorperazine are said not to interact when apomorphine is used for erectile dysfunction, and domperidone is the recommended antiemetic when apomorphine is used for Parkinson s disease. There is evidence that antidepressants, antiepileptics, and ondansetron do not interact adversely. 

The small doses of apomorphine used for erectile dysfunction (2 to 3 mg) do not normally cause vomiting, but nausea does occur in about 7% of patients and the manufacturers say that interaction studies and/or clinical experience show that domperidone, ondansetron or prochlorperazine may safely be given as antiemetics in this patient group. Studies with other antiemetics have not been carried out, so at the moment concurrent use is not recommended. ... 

Note that prochlorperazine should not be given if apomorphine is used for Parkinson s disease, as its dopamine antagonist actions can worsen the disease (see also Levodopa + Antiemetics , p.682). Because apomorphine is highly emetogenic at the doses required for the treatment of Parkinson s disease (1 to 4 mg/hour by subcutaneous infusion), patients with Parkinson s disease requiring apomorphine should be pretreated with domperidone 20 mg three times daily for at least 2 days. Rare reports of extrapyramidal adverse effects have been reported with ondansetron, which may be of relevance in patients with Parkinson s Disease. 

Smith RV, Davis PJ (1978) Regiospecific synthesis of isoapocodeine from 10,11-dimethoxy-aporphine by using Cunninghamella elegans. Appl Environ Microbiol 35 738-742 Sokoloff P, Martres MP, Schwartz JC (1980) Three classes of dopamine receptor (D-2, D-3, D-4) identified by binding studies with H-apomorphine and H-domperidone. Naunyn-Schmiedebergs Arch Pharmacol 315 89-102... 

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