Nausea alfentanil

Alfentanil is associated with a high incidence of nausea and vomiting. Droperidol can reduce emetic symptoms but moclobemide does not (SEDA-17, 79). 

When an opioid is used as the sole agent by the epidural or intrathecal route, the results are disappointing, because of unwanted adverse effects, such as pruritus, nausea, vomiting, respiratory depression, and effects on the neonate, caused by significant systemic absorption (SEDA-17, 85). Hypotension and changes in fetal heart rate are not uncommon (SEDA-21, 91). Combinations of opioids (alfentanil, fentanyl, morphine, sufentanil) with local anesthetics (for example bupivacaine) have therefore been suggested to yield better results (SEDA-18, 83). 

Fentanyl, sufentanil, and alfentanil are frequently used before anesthesia and surgery as a sedative and analgesic, as well as a continuous infusion for primary anesthesia. Because opioids rarely affect the cardiovascular system, they are particularly useful for cardiac surgery and other high-risk cases. Opioids act directly on spinal cord receptors, and are frequently used in epidurals for spinal anesthesia. Side effects may include nausea and vomiting, itching, and respiratory depression. 

A randomised, crossover study in 12 healthy subjects found that oral voriconazole (400 mg twice daily on the first day and 200 mg twice daily on the second day) caused an approximately fivefold increase in the mean AUC of alfentanil 20 micrograms/kg, given intravenously one hour after the last dose of the antifungal. The mean plasma clearance of alfentanil was decreased by 85% and its elimination half-life was prolonged from 1.5 to 6.6 hours. Nausea occurred in 5 subjects and vomiting in 4 subjects. ... 

Observational studies Administration of the optimal dose of alfentanil for percutaneous vertebroplasty has been investigated in 50 patients with osteoporotic vertebral fractures [60 ]. The median effective dose was 1.05 mg/hour when the infusion was begun 30 minutes before the procedure, equating to 0.27 micrograms/kg/minute for a median body weight of 65 kg. Adverse reactions included transient apnea in two patients and nausea and/or vomiting in three. Patients overall satisfaction with the procedure was 89%. 

Observational studies In a study involving 50 patients with osteoporotic vertebral fractures, scheduled for percutaneous vertebroplasty, an infusion of alfentanil 1.05 mg/hour was effective for intraoperative pain rehef transient apnea of less than 10 seconds occurred in only two patients and nausea and vomiting in three [39 ]. 

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