Fentanyl symptom
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Fentanyl Symptoms: A Comprehensive Overview
Acute Adverse Reactions to Fentanyl
Confusion and Somnolence
Fentanyl can induce acute neuropsychiatric symptoms such as confusion and somnolence. In one case, a 55-year-old man experienced acute confusion, intermittent somnolence, and stupor immediately after receiving a small dose of fentanyl combined with diazepam for chest pain. Similarly, a 62-year-old cancer patient developed acute confusion and restlessness after an overdose of fentanyl.
Myoclonus and Hyperalgesia
Generalized myoclonus, particularly affecting the face, and hyperalgesia (increased sensitivity to pain) are also reported symptoms. The 55-year-old man exhibited severe generalized myoclonus and profuse sweating. The cancer patient experienced generalized myoclonus and hyperalgesia upon tactile stimulation.
Visual Hallucinations
Visual hallucinations can occur as a result of fentanyl overdose. The 62-year-old cancer patient reported visual hallucinations, which were alleviated with naloxone administration.
Withdrawal Symptoms
Common Withdrawal Symptoms
Withdrawal from fentanyl can lead to a range of symptoms including sweating, tremors, restlessness, rhinorrhea (runny nose), tachycardia (rapid heart rate), sleeplessness, and yawning. These symptoms were observed in a 40-year-old woman who discontinued fentanyl after long-term use for metastatic breast cancer pain.
Pediatric Withdrawal
In pediatric patients, withdrawal symptoms can include tremors, increased muscle tone, insomnia, and increased respiratory rate. A study involving critically ill infants who received continuous fentanyl infusions found significant correlations between fentanyl dosage and withdrawal severity.
Respiratory Depression and Overdose
Respiratory Depression
Fentanyl overdose can lead to severe respiratory depression, which is a critical symptom requiring immediate medical intervention. Common overdose symptoms include coma, lethargy, and respiratory arrest.
Naloxone Response
Naloxone, an opioid receptor antagonist, is effective in reversing fentanyl-induced respiratory depression and other overdose symptoms. However, due to fentanyl's rapid onset, multiple doses of naloxone may be required .
Dyspnea and Exercise Tolerance
Breakthrough Dyspnea in Cancer Patients
Fentanyl has been shown to alleviate breakthrough dyspnea in cancer patients. A study found that prophylactic subcutaneous fentanyl significantly improved dyspnea, fatigue, walk distance, and respiratory rate during exercise. Another study comparing fentanyl buccal tablets to morphine for episodic breathlessness in cancer patients found faster and greater relief with fentanyl.
COPD and Exercise Endurance
In patients with chronic obstructive pulmonary disease (COPD), inhaled fentanyl citrate improved exercise endurance and delayed the onset of intolerable dyspnea during high-intensity exercise.
Pain Management
Renal Colic
Fentanyl is effective in managing acute pain, such as that caused by renal colic. A clinical trial comparing intravenous fentanyl to intranasal ketamine found fentanyl to be more effective in reducing pain severity.
Postoperative Nausea and Vomiting (PONV)
Fentanyl, when used intrathecally, has been associated with a lower incidence of postoperative nausea and vomiting (PONV). A meta-analysis found that low doses of intrathecal fentanyl significantly reduced PONV incidences.
Conclusion
Fentanyl is a potent opioid with a wide range of effects, from acute neuropsychiatric symptoms and myoclonus to severe withdrawal symptoms and respiratory depression. While it is effective in managing pain and dyspnea, its use requires careful monitoring due to the risk of overdose and dependence. Naloxone remains a critical intervention for fentanyl overdose, although multiple doses may be necessary. Further research and harm-reduction strategies are essential to mitigate the risks associated with fentanyl use.
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