Hello doctor, I have been prescribed a medication for a gastrointestinal problem (chronic constipation - perhaps as a result of a restricted fiber diet due to slow stomach activity which was possibly caused by some damage to the vagus nerve due to a food poisoning incident but we are not sure). However, I have some questions about the anti-constipation drug that I would like answered from a neurological point of view. The drug is called Prucalopride and is described to be a selective, high affinity, serotonin 5-HT 4 receptor antagonist with enterokinetic activities and alters colonic motility patterns via serotonin 5 HT-4 receptor stimulation. One of the common side effects can be a headache (among a few other things but that is the one I am particularly worried about) in the initial stages of taking the drug, but I just wanted to check that if I did experience such a side effect and it continued while taking the medication past the initial stages, that would it cease if I stopped the medication. I just worry about irreversible side effects with prokinetic drugs and drugs which work as serotonin receptor antagonists in the gut as I discovered that another prokinetic drug I was prescribed to speed up stomach emptying (Metoclopramide), which I did not end up taking as it had some irreversible side effects such as a condition called tardive dyskinesia and other serious side effects. What I was most worried about is that there appears to be some similarity in the mechanism of how Metoclopramide and Prucalopride work. The pharmacodynamics of Prucalopride is a serotonin 5-HT4 receptor antagonist and Metoclopramide states that Metoclopramide appears to bind to dopamine D2 receptors and is also a mixed 5-HT3 receptor antagonist/5-HT4 receptor antagonist . I referred to an extract in Wikipedia in the pharmacology section on the page about how Metoclopramide works. I noted how Prucalopride is also said to be a 5-HT4 receptor antagonist. I assume that however, they do not carry the same risk of tardive dyskinesia as I have not seen it documented so far for Prucalopride even though there seem to be some similarities in their mechanism of action. So in short, this is what I wanted to check before taking Prucalopride that it did not cause these similar irreversible conditions and side effects as Metoclopramide and that if Prucalopride did cause me to get headaches, would this stop if I stopped taking Prucalopride. I have one more question. Sometimes, off and on, over the last couple of years, I experienced a kind of noise in perhaps my ears but in the head area anyway, particularly after vomiting a lot due to the slow stomach emptying. I assume this was from some nutritional deficiency, perhaps an electrolyte imbalance, it seems chloride deficiency caused this. I am unsure if I have a chloride deficiency, but I do have low ferritin levels which can cause noises apparently. It seems to have gotten a lot better and sometimes is not there at all. The vomiting has largely stopped so I assume that is why, although it sometimes reappears if I am very stressed. My next question, therefore, is that I just wanted also to check if it was alright to take Prucalopride having had or sometimes still have this situation. Also, because it does state that one must not take Prucalopride with a neurological disorder. I do not know which one is correct.
Hello. You should know that Prucalopride has a different mechanism of action compared to Metoclopramide. So, it does not cause the same adverse effects. Its effects are on 5-HT4 receptors, which are mainly in the gut. These receptors are rare in the central nervous system. There are no contraindications to Prucalopride in patients with any neurological disorders. If you experience headache, it may be a temporary effect and the drug should not be stopped, as the situation is going to improve in the next coming weeks. Only if diarrhea or abdominal cramps occur, the drug should be stopped. This drug does not cause any irreversible neurological disorders. For more information consult a neurologist online -->