Flexeril vs. Tizanidine

See how Flexeril and Tizanidine compare on approved uses, dosing, side effects, and cost.

Key Takeaways

  • Flexeril treats short-term acute muscle spasm, while tizanidine is FDA-approved for spasticity from conditions like multiple sclerosis or spinal cord injury.

  • Flexeril is limited to 2 to 3 weeks of use, whereas tizanidine can be used long-term with regular liver function monitoring.

  • Both drugs commonly cause drowsiness and dry mouth, but tizanidine carries added risks of low blood pressure and rebound hypertension if stopped abruptly.

Flexeril vs. Tizanidine Drug Summary

Flexeril

Flexeril (cyclobenzaprine) is a skeletal muscle relaxant used alongside rest and physical therapy to relieve muscle spasm from acute injuries like strains and sprains. It is taken as a tablet, usually three times a day, and is intended for short-term use of no more than 2 to 3 weeks.

Tizanidine

Tizanidine is a centrally acting alpha-2 agonist used to manage spasticity caused by conditions such as multiple sclerosis or spinal cord injury. It is taken as a tablet or capsule, starting at a low dose and titrated upward every few days based on response and tolerability.

Flexeril vs. Tizanidine Side Effects

Flexeril

Most common
dry mouth (up to 27%)
dizziness (up to 11%)
drowsiness (up to 39%)
fatigue (up to 6%)

Tizanidine

Most common
dry mouth (over 10%)
dizziness (over 10%)
somnolence (over 10%)
asthenia/weakness (over 10%)

Flexeril vs. Tizanidine Dosage

Flexeril

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 5 mg three times daily At the start
Maximum dose 10 mg three times daily If needed
Dose changes 1 increase As tolerated

Tizanidine

Dosage
Dosage Table
STAGE DOSE WHEN
Starting dose 2 mg every 6-8 hours At the start
Maximum dose Up to 36 mg/day If needed
Dose changes 2 increases As tolerated

Flexeril vs. Tizanidine Indications

Flexeril

Flexeril is FDA-approved as a short-term adjunct to rest and physical therapy for muscle spasm caused by acute musculoskeletal injuries such as strains or sprains. It is not approved for spasticity linked to neurological conditions. Some clinicians use it off-label to help with fibromyalgia pain and sleep disturbances.

  • Acute muscle spasm from injury or strain

  • Adjunct to rest and physical therapy

  • Short-term use only, 2 to 3 weeks

  • Off-label for fibromyalgia pain and sleep issues

Tizanidine

Tizanidine is FDA-approved for managing spasticity, a condition marked by stiff, tight muscles caused by damage to the brain or spinal cord, such as from multiple sclerosis or spinal cord injury. It is not approved for general chronic pain unrelated to spasticity or for use in children. Off-label, it is sometimes used for migraine prevention or chronic low back pain.

  • Spasticity from MS or spinal cord injury

  • Off-label for chronic back pain or migraine prevention

  • Can be used long-term, unlike Flexeril

  • Available as tablet or capsule with different absorption

Flexeril vs. Tizanidine Pros and Cons

Flexeril

Flexeril has a simple, flat-dose schedule with no titration needed, making it easy to use for short flare-ups. It has a long track record since 1977 and does not require liver monitoring, but it carries a high sedation rate and several cardiac contraindications.

Pros

  • Simple flat-dose regimen, no titration needed

  • No routine liver monitoring required

  • Fewer serious drug interactions than tizanidine

  • Widely available, inexpensive generic tablets

Cons

  • Highest drowsiness rate of the two (up to 39%)

  • Contraindicated with MAOIs and several heart conditions

  • Not effective for spasticity from CNS disease

  • Restricted to short-term use, 2 to 3 weeks max

Tizanidine

Tizanidine offers flexible dosing that can be titrated to match the severity of spasticity, and it is approved for long-term use unlike Flexeril. It requires periodic liver function tests and careful monitoring for low blood pressure, especially when combined with other blood pressure medications.

Pros

  • Approved for long-term spasticity management

  • Dose can be titrated to match spasticity severity

  • No boxed warning despite its drug class

  • Broader off-label use in migraine and chronic pain

Cons

  • Requires periodic liver function testing

  • Risk of low blood pressure and slowed heart rate

  • Interacts significantly with CYP1A2 inhibitor drugs

  • Abrupt stopping after long-term use can rebound blood pressure

Common Symptoms and Related Diseases You Can Explore

Explore a range of common symptoms the Doctronic Symptom Checker can help you understand.