Now that we understand how the vomiting reflex is triggered, let’s talk about the medications, first we have phenothiazines like prochlorophyrizine and chloropromazine, they block dopamine receptors and they inhibit histamine h1 receptors. Side effects include; bronziness, sedation and tardive dyskinesia, we also have the five ht3 receptors blockers like on densitron grand citron, they block the five ht3 receptors or the serotonin receptors in both ctc and in the periphery, the common side effects of these agents include; constipation, headache and asthenia because of their superior efficacy and longer duration of action, they are important agent in treating chemotherapy-induced nausea and vomiting, we have benzamides analogues like metacapramide which inhibits dopamine receptors in the ctc and antagonize serotonin receptors in the periphery, side effects include extrapyramidal symptoms which are stresslessness dystonia which is involuntary muscle contraction, also it can cause headache and diarrhea. Domipridon is a dopamine, to antagonist its action is similar to mitochopromide although they are chemically different, the main difference between them is that the domipredone does not cross the blood-brain barrier so it has less cns side effects, other side effects that double-protocols are dry mouth diarrhea and drowsiness then we have antihistamine anticholinergic drugs like diphenhydramine and scoplamine, they block masochronic receptors and histamine h1 receptors in the vesibiliar nuclei address effects include drowsiness, confusion blurred vision, dry mouth and urinary retention, then we have butyrophenones like drop pyridol and jalaperidol, their mechanism of action is that they block dopamine receptors. Side effects include that they can cause extrapyramidal symptoms and sedation, dropyridol may prolong qtc interval.
We have soft simpy or neuro-chinen-1 receptor antagonists like apriptant and phosapratent, mechans of action is chemotherapy, metabolites will trigger the elevation of substance in the ctc which will simulate the nk receptors stimulating the vomiting reflex. These agents will target neurokinan 1 receptor in the brain and will block the action of substance, other effects include constipation, diarrhea, headache and hiccups. It is usually administered with other anti-emetics for chemotherapy-induced nausea and vomiting and lastly we have benzodiazepines and corticosteroids for pinzodiazepines, their antimetric potency is low and their beneficial effects rely on having sedative and geologic effect and they can cause amnesia which is short loss of memory, laura zipam and alprazolam, both have been used in combination with other artifacts, adverse effects include hypertension, sedation and urinary incontinence for corticosteroids. Dexamethasone and presulon have been used in combination with other antimetic agents but their antimetic mechanism for action is still unknown, adverse effects that are associated with a single dose or short course of treatment is infrequent but it may include mild fluid retention, insomnia and euphoria.