Tizanidine, sold under the brand name Zanaflex, Sirdalud among others, is a medication that is used to relieve the spasms and increased muscle tone caused by multiple sclerosis (MS, a disease in which the nerves do not function properly and patients may experience weakness, numbness, loss of muscle coordination and problems with vision, speech, and bladder control), stroke, or brain or spinal injury.
Tizanidine is NOT a narcotic but belongs to a class of medications called skeletal muscle relaxants. It works by slowing action in the brain and nervous system to allow the muscles to relax. Many people use the word “narcotic” to refer to all prescription medications that relieve pain, just because Tizanidine is sometimes abused doesn’t qualify it as a narcotic. The term narcotic originally referred medically to any psychoactive compound with numbing or paralysing properties. In the United States, it has since become associated with opiates and opioids, commonly morphine and heroin, as well as derivatives of many of the compounds found within raw opium latex.
How long does tizanidine stay in your system?
Tizanidine itself has a short “half-life” of only about 150 minutes, which means that the body clears the drug within a few hours. However, many people who abuse tizanidine take high doses and may have impaired kidney and liver function from other drug use, so the time the body takes to clear the medication may be prolonged in such cases. Use of other drugs, especially alcohol, further impairs the body’s ability to detoxify from tizanidine.
Even though tizanidine usually clears from the body relatively quickly, the body and brain take a long time to recover from the extremely disruptive effects that the drug has on their ability to function normally, and it takes considerably longer for them to recover after the drug is removed from circulation. This disruption of the body’s normal ability to function causes the withdrawal symptoms, which lasts until the body and brain have fully recovered and resumed normal functioning.
What side effects can this medication cause?
Tizanidine may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- dizziness
- drowsiness
- weakness
- nervousness
- depression
- vomiting
- tingling sensation in the arms, legs, hands, and feet
- dry mouth
- constipation
- diarrhea
- stomach pain
- heartburn
- increased muscle spasms
- back pain
- rash
- sweating
Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:
- nausea
- extreme tiredness
- unusual bleeding or bruising
- lack of energy
- loss of appetite
- pain in the upper right part of the stomach
- yellowing of the skin or eyes
- unexplained flu-like symptoms
- seeing things or hearing voices that do not exist
- slow heartbeat
- changes in vision
Tizanidine may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.
What other information should I know?
Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your response to tizanidine. Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
