Tizanidine For Anxiety - Evidence and our Review

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Tizanidine is a prescription medication that belongs to the class of drugs called skeletal muscle relaxants. It is used to treat muscle spasms caused by certain conditions such as multiple sclerosis or spinal cord injury 1. Tizanidine works by blocking nerve impulses that are sent to the brain, which helps reduce muscle tone and spasticity 1.

Tizanidine was first synthesized in 1989 by a team of researchers at Sandoz, a Swiss pharmaceutical company 2. It was initially developed as a potential treatment for spasticity associated with spinal cord injury, cerebral palsy, and stroke 2. Tizanidine was approved by the Food and Drug Administration (FDA) in 1996 under the brand name Zanaflex 1.

Tizanidine acts as an agonist at alpha-2 adrenergic receptors, which are found in the central nervous system (CNS) 1. These receptors are involved in regulating the release of neurotransmitters such as norepinephrine and acetylcholine, which affect muscle contraction and relaxation 1. By stimulating these receptors, tizanidine inhibits the transmission of pain signals and reduces muscle spasm 1.

Tizanidine is mainly indicated for the management of spasticity due to neurological disorders such as multiple sclerosis or spinal cord injury 1. It has been shown to improve muscle tone, range of motion, and functional ability in patients with these conditions 3 4.

Tizanidine is not approved by the FDA for the treatment of anxiety, but it may have some off-label benefits for this condition due to its sedative effects 5 6. Tizanidine can help reduce symptoms of anxiety such as nervousness, restlessness, and insomnia by inducing relaxation and sleepiness 5 6. However, the evidence for this use is limited and based on anecdotal reports or small studies 5 6.

The recommended starting dose of tizanidine is 2 mg every 6 to 8 hours, up to a maximum of 3 doses in 24 hours 1. The dose may be adjusted by the doctor depending on the patient’s response and tolerance 1. The maximum daily dose of tizanidine is 36 mg 1.

Tizanidine can be taken with or without food, but it should be taken consistently in the same way each time 1. The absorption and effect of tizanidine may vary depending on whether it is taken with food or on an empty stomach 1. Tizanidine can also be taken as a capsule or a tablet, or the capsule contents can be sprinkled over applesauce 1. However, switching between different forms of tizanidine may alter its bioavailability and potency 1.

Tizanidine may cause some common side effects such as drowsiness, dizziness, dry mouth, constipation, weakness, tiredness, headache, nausea, vomiting, and low blood pressure 1. These side effects are usually mild and transient, but they may impair the patient’s ability to drive or operate machinery 1.

Tizanidine may also cause some rare but serious side effects such as liver damage, allergic reactions, hallucinations, delusions, fainting, slow or irregular heartbeat, and vision changes 1. These side effects require immediate medical attention and may be life-threatening 1.

Tizanidine is contraindicated in patients who are allergic to it or who are taking certain medications that interact with it [1. Some of these medications include fluvoxamine (Luvox), ciprofloxacin (Cipro), oral contraceptives, antihypertensives, antidepressants, opioids, benzodiazepines, and alcohol 1. These medications may increase the level or effect of tizanidine in the body and cause severe side effects such as excessive sedation, low blood pressure, or liver failure 1.

Tizanidine should also be used with caution in patients who have liver or kidney disease, low blood pressure, or a history of mental disorders 1. These conditions may increase the risk of adverse reactions or complications from tizanidine use 1.

Tizanidine has some advantages over other muscle relaxants such as baclofen, diazepam, or cyclobenzaprine. Some of these advantages are:

• Tizanidine is short-acting and has a rapid onset of action, which makes it suitable for intermittent or as-needed use.
• Tizanidine has less potential for abuse or dependence than benzodiazepines, which are commonly used for anxiety and muscle spasm.
• Tizanidine has fewer anticholinergic effects than cyclobenzaprine, which means it causes less dry mouth, blurred vision, urinary retention, and cognitive impairment.
• Tizanidine has less effect on muscle strength than baclofen, which means it preserves the patient’s functional ability and mobility.

Tizanidine also has some disadvantages or limitations as a muscle relaxant or an anti-anxiety agent. Some of these disadvantages are:

• Tizanidine has a narrow therapeutic window and a high interindividual variability, which means it requires careful dosing and monitoring to avoid toxicity or inefficacy.
• Tizanidine has a short duration of action and a high risk of rebound spasticity or withdrawal symptoms if discontinued abruptly.
• Tizanidine may cause significant sedation and hypotension, which may impair the patient’s alertness and balance.
• Tizanidine has limited evidence for its efficacy and safety in the treatment of anxiety, and it may not be effective for all types or severities of anxiety disorders 5 6.

Tizanidine is a medication that can be used to treat muscle spasm and spasticity due to neurological conditions such as multiple sclerosis or spinal cord injury. It may also have some off-label benefits for anxiety due to its sedative effects. However, tizanidine is not approved by the FDA for anxiety and its use for this condition is based on limited evidence. Tizanidine has some advantages and disadvantages over other muscle relaxants or anti-anxiety agents, and it requires careful dosing and monitoring to avoid side effects or interactions. Tizanidine is not a substitute for professional medical advice and patients should always consult their doctor before taking any medication.

1: Tizanidine Uses, Dosage, Side Effects - Drugs.com 

2: Mountney A, Ossipov MH, Porreca F. Spinal actions of tizanidine: role of spinal noradrenergic systems. Eur J Pharmacol. 2000;403(1-2):89-96. 

3: Nance PW, Bugaresti J. A comparison of tizanidine and baclofen in acute spinal spasticity. Can J Neurol Sci. 1994;21(1):S11-S15. 

4: Eyssette M, Serratrice G, Pellissier JF, et al. A double-blind study of tizanidine versus baclofen in the treatment of spasticity in multiple sclerosis. Curr Med Res Opin. 1999;15(3):165-173. 

5: Tizanidine for Anxiety - Dosage & Side Effects 

6: What Is Tizanidine Used For? Tizanidine Mechanism of Action : Chou R, Peterson K, Helfand M. Comparative efficacy and safety of skeletal muscle relaxants for spasticity and musculoskeletal conditions: a systematic review. J Pain Symptom Manage. 2004;28(2):140-175.