Prokinetic Therapy Dopamine Antagonists

Metoclopramide (Reglan) is the most commonly used prokinetic drug and the agent that we employ as first line therapy. It is a central and peripheral dopamine receptor (D2) antagonist and a powerful antiemetic at the chemorecep-tor trigger zone level while also being effective in improving gastric emptying by increasing antral contractions and decreasing receptive relaxation of the proximal stomach. However, as many as 40% of patients cannot tolerate metoclopramide because of central nervous system (CNS) side effects. If tolerated orally, the usual dose is 10 to 20 mg 30 minutes before meals and bedtime. One strategy for patients who do tolerate this agent orally is to also use it subcutaneously (sc) during periods of worse nausea or vomiting. Metoclopramide sc can be given by the patient (2 mL [10 mg] 2 or 3 times daily) with oral medication during and after hospitalizations while stepping down to

Ges Disease
FIGURE 31-1. Gastroparesis treatment algorithm. bid = twice daily; GES = gastric electrical stimulation; po = by mouth; qid = 4 times daily; q8h = every 8 hours.

oral therapy alone or as a bolus supplement at home to control intermittent breakthrough nausea.

For patients that have intolerable side effects on meto-clopromide or continued symptomatology, other agents can be used. We frequently substitute Domperidone (Motilium) for metoclopramide. It is a very effective dopamine-2 antagonist, like metoclopramide, and shares its effect on upper gastrointestinal (GI) motility. It is a potent antiemetic at the chemoreceptor trigger zone but does not cross the blood-brain barrier and, therefore, has no CNS side effects. Unfortunately, however, it is not available in the United States despite the fact that its effectiveness and safety have been established in clinical trials.

Domperidone can be obtained from some compounding pharmacies in the United States and from pharmacies in other countries but is not usually covered by health insurance providers. Domperidone, at doses from 10 mg to 30 mg by mouth (po) 4 times daily (qid) (also given 30 minutes before meals and bedtime), has been shown to significantly reduce GI symptoms and hospitalizations from gastroparesis, enhance quality of life, and accelerate gastric emptying of a solid meal. Domperidone does cause increased serum prolactin levels, and the most commonly reported side effects are gynecomastia in men and breast enlargement and lactation in women. These events occur in approximately 5% of treated patients.

Constipation Prescription

Constipation Prescription

Did you ever think feeling angry and irritable could be a symptom of constipation? A horrible fullness and pressing sharp pains against the bladders can’t help but affect your mood. Sometimes you just want everyone to leave you alone and sleep to escape the pain. It is virtually impossible to be constipated and keep a sunny disposition. Follow the steps in this guide to alleviate constipation and lead a happier healthy life.

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