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Flexeril (cyclobenzaprine) Disease Interactions

There are 2 disease interactions with Flexeril (cyclobenzaprine):

Major

Cyclobenzaprine (applies to Flexeril) cardiovascular disease

Major Potential Hazard, Moderate plausibility. Applicable conditions: Hyperthyroidism, Cerebrovascular Insufficiency, History - Cerebrovascular Disease, History - Myocardial Infarction, Hypotension, Dehydration, Congestive Heart Failure

The manufacturers consider the use of cyclobenzaprine to be contraindicated in the acute recovery phase following myocardial infarction and in patients with hyperthyroidism, congestive heart failure, arrhythmias, heart block, and/or conduction disturbances. Cyclobenzaprine is structurally related to the tricyclic antidepressants, which have been reported to cause tachycardia, arrhythmias, heart block, hypertension, hypotension (particularly orthostatic hypotension), thrombosis, thrombophlebitis, myocardial infarction, strokes, congestive heart failure, and ECG abnormalities such as PR and QT interval prolongation. Therapy with cyclobenzaprine should be administered cautiously in patients with a history of cardiovascular or cerebrovascular disease or a predisposition to hypotension, particularly if the intended dosage exceeds those normally used for musculoskeletal conditions. Tachycardia, arrhythmia, palpitation, and hypotension have been reported with the use of cyclobenzaprine in less than 1% of patients.

References

  1. Linden CH, Mitchiner JC, Lindzon RD, Rumack BH "Cyclobenzaprine overdosage." J Toxicol Clin Toxicol 20 (1983): 281-8
  2. "Product Information. Flexeril (cyclobenzaprine)." Merck & Co, Inc, West Point, PA.
  3. O'Riordan W, Gillette P, Calderon J, Stennes RL "Overdose of cyclobenzaprine, the tricyclic muscle relaxant." Ann Emerg Med 15 (1986): 592-3
Moderate

Cyclobenzaprine (applies to Flexeril) anticholinergic effects

Moderate Potential Hazard, Moderate plausibility. Applicable conditions: Gastrointestinal Obstruction, Glaucoma/Intraocular Hypertension, Urinary Retention

Cyclobenzaprine has anticholinergic activity, to which elderly patients are particularly sensitive. Therapy with cyclobenzaprine should be administered cautiously in patients with preexisting conditions that are likely to be exacerbated by anticholinergic activity, such as urinary retention or obstruction; angle-closure glaucoma, untreated intraocular hypertension, or uncontrolled primary open-angle glaucoma; and gastrointestinal obstructive disorders. Glaucoma should be treated and under control prior to initiation of cyclobenzaprine therapy, and intraocular pressure monitored during therapy.

References

  1. Heckerling PS, Bartow TJ "Paradoxical diaphoresis in cyclobenzaprine poisoning." Ann Intern Med 101 (1984): 881
  2. Linden CH, Mitchiner JC, Lindzon RD, Rumack BH "Cyclobenzaprine overdosage." J Toxicol Clin Toxicol 20 (1983): 281-8
  3. "Product Information. Flexeril (cyclobenzaprine)." Merck & Co, Inc, West Point, PA.

Flexeril (cyclobenzaprine) drug interactions

There are 376 drug interactions with Flexeril (cyclobenzaprine)

Flexeril (cyclobenzaprine) alcohol/food interactions

There is 1 alcohol/food interaction with Flexeril (cyclobenzaprine)

Drug Interaction Classification

These classifications are only a guideline. The relevance of a particular drug interaction to a specific individual is difficult to determine. Always consult your healthcare provider before starting or stopping any medication.
Major Highly clinically significant. Avoid combinations; the risk of the interaction outweighs the benefit.
Moderate Moderately clinically significant. Usually avoid combinations; use it only under special circumstances.
Minor Minimally clinically significant. Minimize risk; assess risk and consider an alternative drug, take steps to circumvent the interaction risk and/or institute a monitoring plan.
Unknown No interaction information available.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.