Cyclobenzaprine is a muscle relaxant often used to treat painful, acute musculoskeletal conditions causing muscles spasms (1). These side effects are experienced with varying degrees of intensity and regularity among individuals. Based on clinical trials, drowsiness is reported most often with about 39% of users. This sedative effect may be strong enough to affect daily activities, such as driving and operating heavy machinery.
Another prevalent side effect reported by approximately 32% of cyclobenzaprine users is dry mouth (xerostomia). This is related to its anticholinergic effects on the production of saliva. Patients with symptoms of dry mouth can increase fluid intake and use sugar-free candies to help stimulate saliva production.
About 11% of patients who take cyclobenzaprine go on to develop dizziness. It increases the danger of falls, particularly within older adults who may also be at greater risk because of age-associated stability issues. Healthcare providers may advise patients to get up slowly from the seated or prone posture, as a preventive measure for reducing dizziness.
It also has a 6% incidence of anticholinergic side effects such as constipation. Sounds like a pain in the ass if you ask anyone with tummy troubles prior to this debacle. Diet measures (e.g. increasing dietary fiber and hydration) may be recommended for managing constipation.
Another side effect is a headache which happen in 5% of the users with varying degrees from mild to severe. Headaches are not as universally seen amongst the population like dry mouth and dizziness, however; they can cause significant discomfort that one might need to take an over-the-counter pain reliever for. Patients should consult with their healthcare provider to determine if cyclobenzaprine is safe for them.
Also, up to 3% may experience blurred vision from cyclobenzaprine This side effect can make it difficult to perform visual precision tasks like reading or driving. However, patients who experience blurry vision are generally not allowed to do so until their sight is acceptable.
Cyclobenzaprine has also been known to cause urinary retention, a condition in which urine cannot empty from the bladder completely While this side effect is rarer, it can cause discomfort and even urinary tract infections if not remediated. If the patient finds it difficult to pee, consult with a doctor as soon as possible.
Lastly, more confusion and disorientation may happen especially in elderly patients due to the central nervous system effects of cyclobenzaprine. This can interfere with daily activities and require more frequent followup visits by healthcare providers.
Individual patient prognostic evaluation and disciplined management will likely mitigate these adverse effects associated with cyclobenzaprine. Prescribers must balance the muscle spasm relief benefit against these undesirable effects when providing patients with cyclobenzaprine. Any cyclobenzaprine side effects your patients experience, however mild or severe, deserve a conversation with you to help determine what - if anything - needs to be done differently for an optimized treatment plan.