Will a mixture of 20mg of cyclobenzaprine and 15mg of hydrocodone be fatal?

Flexeril (cyclobenzaprine hcl) & Hydrocodo: Hello. If you allergic reactions to either OR both of these such as difficulty swallowing, tongue swelling, difficulty breathing- then the combo can be fatal. For many patients, taking these two together makes them real sleepy. Normally don't see 20mg of cyclobenzaprine taken at one time. 15mg of hydrocodone sound like 1.5 pills taken at one time. Stagger these meds if you must take these doses.