Fentanyl dosage

Fentanyl is metabolis by the cytochrome P450 isoenzyme CYP3A4 and rifampicin, a potent inducer of CYP3A4, appears to reduce its serum levels and pharmacological efficacy. Thus an increase in fentanyl dosage may be ne ed in patients taking rifampicin. ... 

A patient is prescribed fentanyl (Sublimaze) 50 meg IM 30 minutes before surgery. The nurse has available a vial with a dosage strength of 0.05 mg/1 mL. The nurse calculates the dosage and administers. ... 

FENTANYL Individualize dosage. Monitor vital signs routinely. 

Dose titration - Base appropriate dosage increments on the daily dose of supplementary opioids, using the ratio of 45 mg/24 h of oral morphine to a 12.5 mcg/h increase in transdermal fentanyl dose. 

In obese patients (more than 20% above ideal body weight), determine the alfentanil, remifentanil, and sufentanil dosage on the basis of ideal body weight. Use fentanyl transmucosal with caution in patients with diabetes because it contains approximately 2 g of sugar per unit. 

Fentanyl is 80 to 100 times as potent as morphine. Sufentanil (Sufenta) is 500- to 1,000-fold more potent than morphine, while alfentanil (Alfenta) is approximately 20 times more potent than morphine. Their onset of action is usually less than 20 minutes after administration. Dosage is determined by the lean body mass of the patient, since the drugs are lipophilic and tend to get trapped in body fat, which acts as a reservoir, prolonging their half-life. In addition, redistribution of the drugs from the brain to fat stores leads to a rapid offset of action. Droperidol, a neuroleptic agent, is generally administered in combination with fentanyl for IV anesthesia. 

Despite an intensive research effort over the past two decades involving many innovative approaches in the global academic community and by the pharmaceutical industry, the latter representing an aggregate investment in excess of 2.5 billion, the only new opioid-based pain medications either in clinical development or on the market are alternative dosage forms of the classical opioids, morphine, loperamide, and fentanyl, or compounds such as tramadol. ... 

Dosages and routes of administration For acute (postoperative) pain and for anesthesia, fentanyl is given by the intravenous route. For pre-medication in anesthesia and for break-through pain the compound can also been given as an oral-transmucosal formulation (Ashburn and Streisand, 1994). A transdermal patch has been developed for chronic pain treatment (Jeal and Benfield, 1997 O Siordin, 1998). The intravenous doses for premedication are 50-100 pg, oral-transmucosal systems contain 200-400 pg and patch formulations have a delivery rate of 25-100 pg/h. 

Anyone who sells or distributes fentanyl or one of its analogs, regardless of whether it is pharmaceutically or clandestinely created, can face criminal charges. This includes giving someone else some of a legally prescribed dosage. Any doctor who falsely prescribes fentanyl to someone can face criminal charges. 

Induce and maintain anesthesia using a mixture of fentanyl/ fluanisone with midazolam (Hypnorm/Hypnovel see Note 4). The dosage for these agents is 0.25 mL of each active ingredient plus 0.5 mL of water given IP at a rate of 0.1 mL per mouse. 

Carbopol resins also have been used in controlled-release dosage forms. Especially, the resins Noven AA-1 USP and Carbopol 934P NF are being extensively developed in bioadhesive drug delivery systems for topical, bucal or nasal, ocular, and rectal applications (e.g., Fentanyl ). Noven CA-1 USP and CA-2 USP are used as oral laxative and antidiarrheal products in swallowable and chewable tablets. 

In 113 patients undergoing general anesthesia, intravenous midazolam 15 mg slowed recovery of the twitch height after vecuronium and atracurium compared with diazepam. The recovery index was not altered (162). However, in another study in 20 patients, midazolam 0.3 mg/kg did not affect the duration of blockade, recovery time, intensity of fasciculations, or adequacy of relaxation for tracheal intubation produced by suxamethonium 1 mg/kg, nor the duration of blockade and adequacy of relaxation for tracheal intubation produced by pancuronium 0.025 mg/kg in incremental doses until 99% depression of muscle-twitch tension was obtained (161). Furthermore, in 60 patients undergoing maintenance anesthesia randomly assigned to one of six regimens (etomidate, fentanyl, midazolam, propofol, thiopental plus nitrous oxide, or isoflurane plus nitrous oxide), midazolam did not alter rocuronium dosage requirements (165). 

Effective in the management of severe postoperative, chronic, or cancer pain. Spinal opioids can be administered by a single bolus injection into the epidural or subarachnoid space or by continuous infusion via an indwelling catheter. Dosage requirement by these routes is significantly less than with IV administration (epidural opioid doses 10-fold lower than IV doses intrathecal opioid doses 100-fold lower than IV doses). Morphine, hydromorphone, fentanyl, and sufentanil are effective when administered intrathecally. The most commonly used local anesthetic in continuous epidural infusions is bupivacaine. Fentanyl, morphine, or hydromorphone is usually combined with bupivacaine for epidural infusions. 

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