From the FDA Drug Label
The most common effects associated with cyclobenzaprine overdose are drowsiness and tachycardia Less frequent manifestations include tremor, agitation, coma, ataxia, hypertension, slurred speech, confusion, dizziness, nausea, vomiting, and hallucinations. Rare but potentially critical manifestations of overdose are cardiac arrest, chest pain, cardiac dysrhythmias, severe hypotension, seizures, and neuroleptic malignant syndrome Observation with cardiac monitoring and observation for signs of CNS or respiratory depression, hypotension, cardiac dysrhythmias and/or conduction blocks, and seizures is necessary.
Yes, Flexeril (cyclobenzaprine) can cause hypotension, although it is a rare but potentially critical manifestation of overdose 1.
From the Research
Yes, Flexeril (cyclobenzaprine) can cause hypotension as a side effect, though it's not among the most common adverse reactions. This muscle relaxant works by acting on the central nervous system to relieve muscle spasms and associated pain. When hypotension occurs with cyclobenzaprine, it's typically mild and may present as dizziness or lightheadedness, particularly when changing positions quickly (orthostatic hypotension) 2. The blood pressure-lowering effect is related to the drug's anticholinergic properties and its structural similarity to tricyclic antidepressants, which are known to have effects on blood pressure, including orthostatic hypotension 3. Patients with cardiovascular conditions, the elderly, and those taking other medications that lower blood pressure may be at higher risk for this side effect. If you experience significant dizziness, lightheadedness, or fainting while taking cyclobenzaprine, you should contact your healthcare provider promptly. To minimize the risk of hypotension, it's advisable to change positions slowly, stay well-hydrated, and follow the prescribed dosage, which typically ranges from 5-10 mg three times daily for acute muscle spasm treatment 4. Some studies have shown that lower doses of cyclobenzaprine, such as 5 mg three times daily, can be effective while minimizing the risk of sedation and other side effects, including hypotension 4. However, the most recent and highest quality study on the topic of antidepressant effects on blood pressure, including those related to cyclobenzaprine's mechanism of action, suggests careful consideration of blood pressure status and cardiovascular comorbidities when treating patients with these medications 3.
Some key points to consider:
- Cyclobenzaprine can cause hypotension, particularly orthostatic hypotension, due to its anticholinergic properties and structural similarity to tricyclic antidepressants.
- Patients at higher risk include those with cardiovascular conditions, the elderly, and those taking other medications that lower blood pressure.
- Minimizing the risk of hypotension involves careful dosing, typically 5-10 mg three times daily, staying well-hydrated, and changing positions slowly.
- Recent studies emphasize the importance of considering blood pressure status and cardiovascular comorbidities when prescribing medications like cyclobenzaprine 3.