Does taking 20mg cyclobenzaprine at once to something bad for the liver? it is the only way to get relief with my back pain.

Cyclobenzaprine: The recommended dose is 5- 10 mg 2-3 times /day for 2- 3 wks. It needs to be at lower dose for people with liver problem. Decision had to be made based on your other conditions and medications you are on. It is better to take lower dose with other modalities to control the pain.

Possibly: The maximum recommended dose of Flexeril (cyclobenzaprine hcl) is 10 mg three times a day. Taking 20 mg at one time is not recommended. This could potentially damage the liver especially if taken frequently and/or along with other medications metabolized by the liver. You should discuss this with the doctor who prescribed Flexeril (cyclobenzaprine hcl) for you.

Probably fine: Although the drug data sheet notes a potential for liver toxicity, it notes it occurred in less than 1% of patients studied. Based on the data it is low risk, so if you need the drug take it and have your primary care doctor monitor your liver function test labs if he or she believes it is indicated