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The most common adverse reactions of opioids are respiratory depression and skeletal muscle rigidity, particularly of the truncal muscles. ALFENTA (alfenta (alfenta (alfentanil) nil) nil) may produce muscular rigidity that involves the skeletal muscles of the neck and extremities. See CLINICAL PHARMACOLOGY, WARNINGS, and PRECAUTIONS on the management of respiratory depression and skeletal muscle rigidity.

The adverse experience profile from 696 patients receiving ALFENTA (alfenta (alfenta (alfentanil) nil) nil) for Monitored Anesthesia Care (MAC) is similar to the profile established with ALFENTA (alfenta (alfenta (alfentanil) nil) nil) during general anesthesia. Respiratory events reported during MAC included hypoxia, apnea, and bradypnea. Other adverse events reported by patients receiving ALFENTA (alfenta (alfenta (alfentanil) nil) nil) for MAC, in order of decreasing frequency, were nausea, hypotension, vomiting, pruritus, confusion, somnolence and agitation.

The following adverse reaction information is derived from controlled and open clinical trials in 785 patients who received intravenous ALFENTA (alfenta (alfenta (alfentanil) nil) nil) during induction and maintenance of general anesthesia. The controlled trials included treatment comparisons with fentanyl, thiopental sodium, enflurane, saline placebo and halothane. The incidence of certain side effects is influenced by the type of use, e.g., chest wall rigidity has a higher reported incidence in clinical trials of alfenta (alfenta (alfenta (alfentanil) nil) nil) nil induction, and by the type of surgery, e.g., nausea and vomiting have a higher reported incidence in patients undergoing gynecologic surgery. The overall reports of nausea and vomiting with ALFENTA (alfenta (alfenta (alfentanil) nil) nil) were comparable to fentanyl.

Incidence Greater than 1% - Probably Causally Related (Derived from clinical trials)

Gastrointestinal: nausea (28%), vomiting (18%)
Cardiovascular: arrhythmia, bradycardia (14%), hypertension (18%), hypotension (10%), tachycardia (12%)
Musculoskeletal: chest wall rigidity (17%), skeletal muscle movements*
Respiratory: apnea*, postoperative respiratory depression
Central Nervous System: blurred vision, dizziness*, sleepiness/postoperative sedation

*Incidence 3% to 9%
All others 1% to 3%

Incidence Less than 1% - Probably Causally Related (Derived from clinical trials)

Adverse events reported in post-marketing surveillance, not seen in clinical trials, are italicized.

Body as a whole: anaphylaxis
Central Nervous System: headache*, myoclonic movements, postoperative confusion*, postoperative euphoria*, shivering*
Dermatological: itching*, urticaria*
Injection Site: pain*
Musculoskeletal: skeletal muscle rigidity of neck and extremities

Respiratory: bronchospasm, hypercarbia*, laryngospasm*

*Incidence 0.3% to 1%

Drug Abuse And Dependence

ALFENTA (alfenta (alfenta (alfenta (alfentanil) nil) nil) nil hydrochloride) is a Schedule II controlled drug substance that can produce drug dependence of the morphine type and therefore has the potential for being abused.

Opioid analgesics have been associated with abuse and dependence in health care providers and others with ready access to such drugs. ALFENTA (alfenta (alfenta (alfentanil) nil) nil) should be handled accordingly.