From the Guidelines
Cyclobenzaprine should be discontinued before anesthesia due to its potential to interact with sedatives and anesthetic agents, causing adverse anticholinergic effects. The medication has a relatively long half-life and can cause peripheral and central anticholinergic activity, leading to norepinephrine potentiation 1. Some of the adverse effects of cyclobenzaprine include hallucinations, confusion, drowsiness, constipation, urinary retention, and dry mouth, which can be exacerbated by anesthesia medications.
Key Considerations
- The potential for serotonin syndrome when cyclobenzaprine is used concomitantly with monoamine oxidase inhibitors 1
- The risk of withdrawal symptoms, such as malaise, nausea, and headache, if cyclobenzaprine is discontinued abruptly, which can be mitigated by tapering the medication over 2 to 3 weeks 1
- The importance of informing the anesthesiologist about cyclobenzaprine use during the pre-operative consultation to determine the best course of action on an individual basis
Perioperative Management
- Given the lack of clear guidance in the literature, the decision to discontinue cyclobenzaprine before anesthesia should be made based on the individual patient's medical history, the type of surgery planned, and the anesthesia protocol to be used 1
- In general, it is recommended to discontinue cyclobenzaprine 24 hours before receiving anesthesia to minimize the risk of adverse interactions and effects.
From the Research
Cyclobenzaprine Safety Before Anesthesia
- The safety of cyclobenzaprine before anesthesia is not directly addressed in the provided studies, but some information can be inferred from the available data.
- A study from 2 found that cyclobenzaprine exhibits high-affinity noncompetitive antagonism at the histamine H1 receptor, which may contribute to its sedative effects.
- Another study from 3 compared the risk of encephalopathy associated with oral baclofen to other muscle relaxants, including cyclobenzaprine, and found that baclofen was associated with a greater risk of encephalopathy.
- A systematic review from 4 summarized the evidence for the comparative efficacy and safety of skeletal muscle relaxants, including cyclobenzaprine, and found that cyclobenzaprine is effective for musculoskeletal conditions, but the evidence for its safety is limited.
- A study from 5 found that co-prescription of strong CYP1A2 inhibitors with tizanidine increased the risk of hypotension, but the risk associated with cyclobenzaprine was lower.
Potential Interactions with Anesthesia
- A study from 6 discussed the precautions that must be taken when using vasoconstrictors with certain patients, especially those with cardiovascular disease, and highlighted the importance of considering drug interactions before administration of a local anesthetic with a vasoconstrictor.
- Although the study from 6 did not specifically address cyclobenzaprine, it suggests that caution should be exercised when using muscle relaxants in combination with other medications, including anesthetics.
Conclusion is not allowed, the response will continue with more subheadings if needed
More Information
- More research is needed to fully understand the safety of cyclobenzaprine before anesthesia, particularly in terms of its potential interactions with anesthetics and other medications.
- The available evidence suggests that cyclobenzaprine is generally safe and effective for musculoskeletal conditions, but its use should be carefully considered in patients with certain medical conditions or those taking other medications.