Dolasetron Mesylate hydrate

Acute gastroenteritis in children: role of anti-emetic medication for gastroenteritis-related vomiting

Acute gastroenteritis is associated with significant morbidity in developed countries and each year is the cause of death of several million children in developing countries. Acute gastroenteritis is usually self-limiting. Oral rehydration therapy (ORT) is effective and successful in the majority of patients. Vomiting is common at the outset of viral gastroenteritis and can limit the effectiveness of ORT. Treatment with newer anti-emetic medications has been reported to facilitate ORT and to minimize the risk of dehydration and the need for intravenous hydration and hospitalization. The role of anti-emetic medications in the treatment of gastroenteritis-related vomiting is not clear. Some physicians agree with the use of anti-emetic medications because vomiting is unpleasant and distressing for the child and parents alike, and because vomiting can increase the likelihood of dehydration, electrolyte imbalance, and the need for intravenous hydration or hospitalization. Several surveys have shown that anti-emetic medications are commonly prescribed in the treatment of pediatric gastroenteritis and that adverse events are uncommon. Efficacy studies of the newer anti-emetic medications are now available and reveal that some are effective and help facilitate ORT. Other physicians disagree with the use of anti-emetic medications because acute gastroenteritis is a self-limiting condition, vomiting might help rid the body of toxic substances, there was previously a relative lack of published evidence of clinical benefit, and there are potential adverse events associated with the use of an anti-emetic medication. Anti-emetic medications that are currently available include ondansetron, granisetron, tropisetron, dolasetron, ramosetron, promethazine, dimenhydrinate, metoclopramide, domperidone, droperidol, prochlorperazine, and trimethobenzamide. Randomized, placebo-controlled trials suggest that ondansetron is efficacious and superior to other anti-emetic medications in the treatment of gastroenteritis-related vomiting. A recent double-blind clinical trial showed that a single oral dose of ondansetron reduces gastroenteritis-related vomiting and facilitates ORT without significant adverse events. Ondansetron shows promise as a first-line anti-emetic, and judicious use of this agent might increase the success of ORT, minimize the need for intravenous therapy and hospitalization, and reduce healthcare costs. Ondansetron should be considered in situations where vomiting hinders ORT, but a larger randomized, placebo-controlled trial is necessary before the medication can be routinely recommended for the treatment of gastroenteritis-related vomiting in children.

Prevention and treatment of postoperative nausea and vomiting

Purpose: The physiology, risk factors, and prevention and treatment of postoperative nausea and vomiting (PONV) are discussed.
Summary: Factors to consider when determining a patient's risk for PONV include sex, history of PONV, history of motion sickness, smoking status, duration of anesthesia, use of opioids, and type of surgery. Receptors that, when activated, can cause nausea or vomiting or both include dopamine type 2, serotonin type 3, histamine type 1, and muscarinic cholinergic type 1 receptors. Patients at moderate to high risk for PONV benefit from the administration of a prophylactic antiemetic agent that blocks one or more of these receptors. Effective agents include transdermal scopolamine, prochlorperazine, promethazine, droperidol, ondansetron, dolasetron, granisetron, and dexamethasone. In high-risk patients, combining two or more antiemetics with different mechanisms of action has been shown to be more effective than using a single agent. In addition to administering a prophylactic antiemetic, it is important to reduce the patient's risk by considering regional anesthesia, considering inducing and maintaining general anesthesia with propofol, ensuring good intravenous hydration, avoiding hypotension, and providing effective analgesia. If PONV occurs in the immediate postoperative period, it is best treated with an antiemetic agent from a pharmacologic class different from that of the prophylactic agent.
Conclusion: Prophylactic antiemetic therapy for PONV is effective, but combinations of agents may be necessary for high-risk patients. Nonpharmacologic strategies are also important.

Pharmacological prophylaxis and management of adult postoperative/postdischarge nausea and vomiting

Postoperative nausea and vomiting (PONV) is a relatively common complication that can adversely affect the quality of a patient's postoperative recovery. Factors to consider when determining a patient's risk for developing PONV include female gender, history of PONV, history of motion sickness, nonsmoking status, postoperative use of opioids, use of inhaled anesthetic agents, and use of nitrous oxide. Receptors that, when activated, can cause PONV include dopamine type-2, serotonin type-3, histamine type-1, muscarinic cholinergic type-1, and neurokinin type-1. Patients with a moderate-to-high risk of developing PONV will benefit from the administration of a prophylactic antiemetic agent that blocks one or more of these receptors. Effective agents for prophylaxis include transdermal scopolamine, prochlorperazine, promethazine, droperidol, ondansetron, dolasetron, granisetron, dexamethasone, and aprepitant. In the highest-risk patients, combining two or more prophylactic antiemetics with different mechanisms of action has been shown to be more effective than a single agent. In addition, the patient's risk could be reduced by considering the use of regional anesthesia, maintaining general anesthesia with propofol rather than with inhaled anesthetic agents, ensuring good intravenous hydration, and providing effective pain management using a multimodal approach (eg, minimizing the use of opioids). If PONV does occur in the immediate postoperative period, it is best treated with an antiemetic agent from a different pharmacologic class than the agent that was administered for prophylaxis. Once a patient is discharged, alternative formulations of antiemetics such as ondansetron oral or dissolving tablets or promethazine tablets or suppositories can be used.

Prevention and treatment of postoperative nausea and vomiting

Pain, nausea and vomiting are frequently listed by patients as their most important perioperative concerns. With the change in emphasis from an inpatient to outpatient hospital and office-based medical/surgical environment, there has been increased interest in the 'big little problem' of postoperative nausea and vomiting (PONV). Currently, the overall incidence of PONV is estimated to be 25 to 30%, with severe, intractable PONV estimated to occur in approximately 0.18% of all patients undergoing surgery. PONV can lead to delayed postanaesthesia care unit (PACU) recovery room discharge and unanticipated hospital admission, thereby increasing medical costs. The aetiology and consequences of PONV are complex and multifactorial, with patient-, medical- and surgery-related factors. A thorough understanding of these factors, as well as the neuropharmacology of multiple emetic receptors [dopaminergic, muscarinic, cholinergic, opioid, histamine, serotonin (5-hydroxy-tryptamine; 5-HT)] and physiology [cranial nerves VIII (acoustic-vestibular), IX (glossopharyngeal) and X (vagus), gastrointestinal reflex] relating to PONV are necessary to most effectively manage PONV. Commonly used older, traditional antiemetics for PONV include the anticholinergics (scopolamine), phenothiazines (promethazine), antihistamines (diphenhydramine), butyrophenones (droperidol) and benzamides (metoclopramide). These antiemetics have adverse effects such as dry mouth, sedation, hypotension, extrapyramidal symptoms, dystonic effects and restlessness. The newest class of antiemetics used for the prevention and treatment of PONV are the serotonin receptor antagonists (ondansetron, granisetron, tropisetron, dolasetron). These antiemetics do not have the adverse effects of the older, traditional antiemetics. Headache and dizziness are the main adverse effects of the serotonin receptor antagonists in the dosages used for PONV. The serotonin receptor antagonists have improved antiemetic effectiveness but are not as completely efficacious for PONV as they are for chemotherapy-induced nausea and vomiting. Older, traditional antiemetics (such as droperidol) compare favourably with the serotonin receptor antagonists regarding efficacy for PONV prevention. Combination antiemetic therapy improves efficacy for PONV prevention and treatment. In the difficult-to-treat PONV patient (as in the chemotherapy patient), suppression of numerous emetogenic peripheral stimuli and central neuroemetic receptors may be necessary. This multimodal PONV management approach includes use of: (i) multiple different antiemetic medications (double or triple combination antiemetic therapy acting at different neuroreceptor sites); (ii) less emetogenic anaesthesia techniques; (iii) adequate intravenous hydration; and (iv) adequate pain control.

A systematic approach to the management of postoperative nausea and vomiting

Postoperative nausea and vomiting (PONV), a common complication after anesthesia and surgery, often results in delayed discharge with the patient's unpleasant symptoms continuing at home. To effectively prevent and treat PONV, it is important to understand the factors implicated in PONV, the mechanisms of PONV, the pharmacology of the antiemetic agents, and the nonpharmacologic measures that have been shown to be effective. The cause of PONV is likely to be multifactorial, with important predictors being female gender, history of PONV, and history of motion sickness. The vomiting center can be triggered by activation of dopamine, serotonin (type 3), histamine (type 1), and muscarinic cholingergic receptors in the chemoreceptor trigger zone and the nucleus tractus solitarus, as well as acetylcholine receptors in the vestibular apparatus, vagal afferents from the periphery, and the endocrine environment. Antiemetic agents such as the serotonin antagonists (eg, ondansetron, dolasetron), droperidol, antihistamines (eg, diphenhydramine, dimenhydrinate), and promethazine can prevent and treat PONV effectively. Transdermal scopolamine and dexamethasone have a role in the prevention of PONV, particularly for certain high-risk patients. Nonpharmacologic measures and alternative treatments such as hydration, maintaining blood pressure, acupressure techniques, trancutaneous acupoint stimulation, and isopropyl alcohol must not be overlooked. Finally, an evidence-based algorithm for the prevention and treatment of PONV in adults is presented.