Tizanidine
Tizanidine: instructions for use and reviews
- 1. Release form and composition
- 2. Pharmacological properties
- 3. Indications for use
- 4. Contraindications
- 5. Method of application and dosage
- 6. Side effects
- 7. Overdose
- 8. Special instructions
- 9. Application during pregnancy and lactation
- 10. Use in childhood
- 11. In case of impaired renal function
- 12. For violations of liver function
- 13. Use in the elderly
- 14. Drug interactions
- 15. Analogs
- 16. Terms and conditions of storage
- 17. Terms of dispensing from pharmacies
- 18. Reviews
- 19. Price in pharmacies
Latin name: Tizanidine
ATX code: M03BX02
Active ingredient: Tizanidine (Tizanidine)
Manufacturer: Teva Pharmaceutical Works Private Co. (Hungary), Berezovsky pharmaceutical plant (Russia)
Description and photo update: 2018-22-10
Prices in pharmacies: from 119 rubles.
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Tizanidine is a drug with a central muscle relaxant effect, used for painful muscle spasms.
Release form and composition
Tizanidine dosage form - tablets: biconvex, round, almost white with a yellowish tinge or white (10 pieces of blister packs, in a cardboard box 3 or 6 packs; 15 pieces each in a blister, in a cardboard box 2 or 4 packaging; 20 pcs. in blister packs, in a cardboard bundle 3 packs; 30 pcs. in a blister strip, in a cardboard bundle 1 or 2 packs; 30, 60 or 100 pcs. in cans, in a cardboard bundle 1 can).
Composition of 1 tablet:
- active substance: tizanidine - 2 or 4 mg (tizanidine hydrochloride - 2.288 or 4.576 mg);
- auxiliary components (2/4 mg): magnesium stearate - 1.1 / 2.2 mg; microcrystalline cellulose - 50.512 / 101.024 mg; colloidal silicon dioxide - 1.1 / 2.2 mg; anhydrous lactose - 55/110 mg.
Pharmacological properties
Pharmacodynamics
Tizanidine is one of the centrally acting muscle relaxants.
The main effects of the active substance:
- stimulation of presynaptic alpha-2-adrenergic receptors of the spinal cord;
- suppression of the release of neurotransmitter amino acids that stimulate receptors for N-methyl-D-aspartate (NMDA receptors), which is the cause of inhibition of polysynaptic transmission of excitation in the spinal cord. Since this mechanism is responsible for excess muscle tone, when it is suppressed, the tone decreases;
- decrease in muscle rigidity during passive movements, due to which there is a decrease in resistance to passive movements and an increase in the volume of active movements;
- an increase in the strength of contractions of the arbitrary nature of skeletal muscles;
- reduction of clonic seizures and spasms.
Pharmacokinetics
Absorption: the substance is absorbed almost completely and quickly. The maximum plasma concentration - 12.3 and 15.6 ng / ml after a single and multiple doses of the drug at a dose of 4 mg, respectively, is reached after about 1 hour. The average bioavailability is approximately 34% (associated with pronounced metabolism).
Distribution: binding to plasma proteins - 30%; the average value of the volume of distribution is 2.6 l / kg. Pharmacokinetics in the dose range from 4 to 20 mg is linear. When taken orally, tizanidine can reliably predict the values of its plasma concentration in the blood.
Metabolism: occurs quickly, about 95% - in the liver, followed by the formation of inactive metabolites. Tizanidine is mainly metabolized by the isoenzyme 1A2 of the cytochrome P450 system.
Excretion: the half-life of a substance from the bloodstream varies from 2 to 4 hours. Excreted as metabolites mainly by the kidneys (approximately 70% of the dose); unchanged substance - about 4.5%.
The average maximum concentration of the drug in plasma in renal failure (creatinine clearance ≤ 25 ml / min) increases 2 times compared with that in healthy volunteers, the final half-life is 14 hours, which entails a significant increase in the systemic bioavailability of the substance.
Hepatic dysfunction may lead to increased systemic exposure to tizanidine.
Indications for use
- painful muscle spasms;
- spasticity of skeletal muscles associated with diseases and damage to the spinal cord, multiple sclerosis.
Contraindications
Absolute:
- liver dysfunction in severe course;
- combined use with alpha-2-adrenergic agonists, fluvoxamine, ciprofloxacin and other potent inhibitors of the CYP1A2 isoenzyme;
- galactose intolerance, lactase deficiency, glucose-galactose malabsorption;
- pregnancy and lactation;
- children up to age 18;
- individual intolerance to the components that make up the drug.
Relative (diseases / conditions in the presence of which Tizanidine is prescribed with caution, in some cases - under the control of laboratory parameters of the functional state of the heart and monitoring of ECG indicators):
- arterial hypotension;
- moderately severe hepatic dysfunction;
- congenital lengthening of the QT interval;
- bradycardia;
- renal failure;
- combined use with norfloxacin, ticlopidine, beta-blockers, diuretics, ethanol, oral contraceptives, antihypertensive, antiarrhythmic and sedative drugs, digoxin, cimetidine, rofecoxib;
- age from 65 years.
Instructions for the use of Tizanidine: method and dosage
Tizanidine is taken orally.
The doctor selects the dose individually, since the drug has a narrow therapeutic index and high variability of plasma concentration in the blood.
The minimum risk of developing adverse reactions is observed when taking the drug 3 times a day, 2 mg. For painful muscle spasm, a single dose may be increased to 4 mg. In severe cases, an additional 2 or 4 mg may be prescribed by your doctor at bedtime.
With spasticity of skeletal muscles associated with neurological diseases, the dosage regimen is set individually.
The maximum daily dose at the beginning of therapy is 6 mg in 3 divided doses. In the future, with an interval of 3–7 days, it may increase by 2–4 mg.
The optimal therapeutic effect, as a rule, is achieved with a daily dose of 12-24 mg in 3-4 divided doses with observance of equal intervals of time. The maximum dose is 36 mg per day.
Patients over 65 years of age are advised to start taking Tizanidine with the minimum dose. In the future, the dosage regimen is set taking into account the optimal ratio of effectiveness and tolerance.
The recommended initial dose for creatinine clearance ≤ 25 ml / min is 2 mg once a day. Dose escalation should be done slowly, gradually, taking into account the effectiveness and tolerability. If a more pronounced effect is required, it is recommended to first increase the single dose, then the frequency of use.
Cancellation of tizanidine should be carried out gradually, which will reduce the likelihood of a rebound increase in blood pressure and tachycardia. This is especially true in cases of long-term use of the drug or therapy in high doses.
Side effects
Possible adverse reactions (> 10% - very common;> 1% and 0.1% and 0.01% and <0.1% - rarely; <0.01% - very rare, taking into account reports of individual cases):
- digestive system: very often - gastrointestinal disorders, xerostomia; often - nausea;
- cardiovascular system: often - lowering blood pressure (in some cases it is pronounced, up to loss of consciousness and collapse); infrequently - bradycardia;
- nervous system: very often - dizziness, drowsiness;
- musculoskeletal system: very often - muscle weakness;
- subcutaneous tissue / skin: allergic reactions (in particular, rash);
- psyche: often - hallucinations, insomnia, sleep disturbances;
- laboratory parameters: often - increased activity of liver microsomal enzymes;
- general disorders: very often - increased fatigue, withdrawal syndrome.
With a sharp withdrawal of Tizanidine after its prolonged use or taking in high doses, as well as after combined use with drugs with antihypertensive action, the development of tachycardia and an increase in blood pressure was noted. In some cases, this led to acute disorders of cerebral circulation. In connection with the above, the cancellation of therapy should be carried out gradually.
There are reports of such violations (the causal relationship has not been established, the frequency of occurrence of these side effects cannot be established):
- nervous system: vertigo;
- psyche: anxiety disorders, hallucinations, confusion;
- biliary tract, liver: liver failure, acute hepatitis;
- organ of vision: blurred vision;
- general disorders: asthenia, withdrawal syndrome.
Overdose
The main symptoms: vomiting, nausea, a marked decrease in blood pressure, lengthening of the QTc interval, drowsiness, dizziness, anxiety, miosis, coma, respiratory failure.
Therapy: to remove tizanidine from the body, it is recommended to perform gastric lavage, intake of a large amount of liquid, repeated administration of activated carbon. Also, accelerated excretion of the substance is facilitated by forced diuresis. In the future, symptomatic therapy is carried out.
Recovery in all cases of overdose, including taking 400 mg of Tizanidine, was uneventful.
special instructions
While taking Tizanidine, hypotension may develop. With a pronounced decrease in blood pressure, collapse and loss of consciousness are possible.
You must refrain from drinking alcohol during treatment.
There is information about cases of development of violations of hepatic function, however, when taking the drug in a daily dose of 12 mg, this rarely happens. In connection with the above, patients using Tizanidine at a dose of 12 mg per day, in the first 4 months of therapy, are recommended to monitor functional liver function tests once a month. Also, hepatic function should be monitored when clinical signs appear suggesting liver dysfunction, including unexplained nausea, anorexia, and fatigue. With a steady increase in serum levels of alanine aminotransferase and aspartate aminotransferase by 3 times in comparison with the upper limit of the norm, the drug is canceled.
Influence on the ability to drive vehicles and complex mechanisms
Taking into account the profile of adverse reactions, it is recommended to refuse from driving during the period of therapy.
Application during pregnancy and lactation
According to the instructions, Tizanidine is contraindicated for use during pregnancy and lactation (there are no clinical data confirming the safety / efficacy of the drug in this group of patients).
Pediatric use
Tizanidine is not prescribed for children under the age of 18, which is due to the lack of evidence of efficacy / safety.
With impaired renal function
In renal failure with creatinine clearance ≤ 25 ml / min, therapy should be performed with caution.
For violations of liver function
In severe liver disorders, Tizanidine is not prescribed, in moderate liver disorders, the drug should be used with caution.
Use in the elderly
Patients over 65 years of age are prescribed Tizanidine with caution; at the beginning of therapy, the minimum doses are indicated. In the future, the dosage regimen is set taking into account the optimal ratio of effectiveness and tolerance.
Drug interactions
Features of the combined use of Tizanidine with inducers / inhibitors of the isoenzyme CYP1A2:
- inhibitors: an increase in the plasma concentration of tizanidine in the blood, which can cause the onset of symptoms of an overdose, including a prolongation of the QTc interval; use with fluvoxamine and ciprofloxacin is contraindicated, since this can lead to a prolonged decrease in blood pressure, accompanied by dizziness, drowsiness, a decrease in the speed of psychomotor reactions (in some cases, up to loss of consciousness and collapse); the combination with other inhibitors of the CYP1A2 isoenzyme, including antiarrhythmics, cimetidine, some fluoroquinolones, rofecoxib, oral contraceptives and ticlopidine, is not recommended;
- inducers: a decrease in the plasma level of tizanidine, which may lead to a decrease in the effectiveness of the drug.
Combinations that require caution when prescribing:
- drugs that prolong the QT interval, including amitriptyline, cisapride, azithromycin;
- rifampicin: a significant decrease in the plasma concentration of tizanidine in the blood is possible. In cases of the need for combined use, an increase in the dose of Tizanidine is recommended;
- other alpha-2-adrenergic agonists (including clonidine): this combination can potentially increase the hypotensive effect (the combination is recommended to be avoided);
- drugs with an antihypertensive effect, including diuretics: a pronounced decrease in blood pressure (in some cases up to loss of consciousness and collapse) and bradycardia are possible. With the abrupt withdrawal of tizanidine after the combined therapy, the occurrence of tachycardia and an increase in blood pressure were noted, which in some cases can lead to acute disturbance of cerebral circulation;
- drugs with sedative and hypnotic effects (benzodiazepine, baclofen) and some other drugs, such as antihistamines: the sedative effect of tizanidine may increase;
- ethanol: an increase in the likelihood of developing adverse reactions;
- smoking: the systemic bioavailability of tizanidine in male smokers is significantly reduced; during prolonged therapy, higher doses of the drug may be required.
Analogs
Tizanidine analogs are Sirdalud, Tizalud, Tizanil.
Terms and conditions of storage
Store in a place protected from light and moisture at temperatures up to 25 ° C. Keep out of the reach of children.
The shelf life is 3 years.
Terms of dispensing from pharmacies
Dispensed by prescription.
Reviews about Tizanidine
According to reviews, Tizanidine is an effective drug, however, significant side effects are frequent. These include drowsiness, weakness, severe dizziness and urge to vomit, which may lead to drug withdrawal.
The price of Tizanidine in pharmacies
The approximate price for Tizanidine (30 tablets per pack) is 110–160 rubles.
Tizanidine: prices in online pharmacies
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Drug name Price Pharmacy |
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Tizanidine 2 mg tablets 30 pcs. 119 RUB Buy |
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Tizanidine 2 mg tablets 30 pcs. 129 RUB Buy |
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Tizanidine 4 mg tablets 30 pcs. 130 RUB Buy |
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Tizanidine 2mg tablets 30 pcs. 133 rbl. Buy |
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Tizanidine tablets 4mg 30 pcs. 152 RUB Buy |
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Tizanidine 4 mg tablets 30 pcs. RUB 185 Buy |
Anna Kozlova Medical journalist About the author
Education: Rostov State Medical University, specialty "General Medicine".
Information about the drug is generalized, provided for informational purposes only and does not replace the official instructions. Self-medication is hazardous to health!
