Flexeril Does Not Significantly Lower Blood Pressure
Flexeril (cyclobenzaprine) is not a blood pressure-lowering medication and does not produce clinically meaningful reductions in blood pressure. Cyclobenzaprine is a centrally-acting muscle relaxant indicated for acute musculoskeletal conditions, not for hypertension management.
Evidence Base
The provided evidence does not contain any data specifically addressing cyclobenzaprine's effects on blood pressure. The available research on cyclobenzaprine focuses on its efficacy for muscle spasm relief and its adverse effect profile, which primarily includes sedation and dry mouth 1.
In clinical trials of cyclobenzaprine at doses of 2.5 mg, 5 mg, and 10 mg three times daily, blood pressure changes were not reported as a primary or secondary outcome, suggesting no clinically significant effect 1.
The most common adverse effects of cyclobenzaprine are somnolence (dose-related) and dry mouth, with no mention of hypotension or blood pressure reduction as a notable side effect 1.
Clinical Context
For comparison, established antihypertensive medications produce predictable blood pressure reductions:
Standard antihypertensive monotherapy (ACE inhibitors, ARBs, calcium channel blockers, diuretics, beta-blockers) reduces office blood pressure by approximately 9/5 mmHg 2.
Combination therapy with three drugs at half-standard dose can lower office blood pressure by up to 20/11 mmHg over the short term 2.
Even medications not primarily intended for blood pressure control but which have documented hypotensive effects (such as acetaminophen or NSAIDs) show measurable impacts on blood pressure monitoring 3, 4.
Important Clinical Caveat
While cyclobenzaprine does not lower blood pressure, its sedative effects could theoretically cause orthostatic symptoms that might be confused with hypotension. However, this represents a postural effect rather than true blood pressure reduction 1.
Patients taking cyclobenzaprine who also require blood pressure management should have their hypertension treated with appropriate antihypertensive agents, as cyclobenzaprine provides no therapeutic benefit for blood pressure control 2.
If a patient on cyclobenzaprine experiences dizziness, this is more likely related to the medication's central nervous system effects (sedation) rather than blood pressure lowering 1.