Tizanidine-ratiopharm

Tizanidine ratiopharm is a muscle relaxant with a central effect on skeletal muscles.

Tizanidine is used as an antispasmodic in the treatment of painful acute muscle spasms, as well as chronic cerebral spastic spasms. The drug reduces resistance to relatively passive movements, suppresses clonic spasms with spasms, and can also improve voluntary muscle strength. [ 1 ]

Indications Tizanidine-ratiopharm

It is used for chronic convulsive conditions caused by disorders of the central nervous system. In addition, it is prescribed in case of local convulsions affecting muscles.

Release form

The drug is released in the form of tablets - 10 pieces inside a cell plate; inside a pack - 3 such plates.

Pharmacodynamics

The drug has a direct effect on the spinal cord, where it slows down the processes of excitatory amino acid release that stimulate NMDA endings. This effect is most likely associated with the stimulation of the activity of α2-endings. As a result, there is suppression of polysynaptic signal transmission along interneuronal connections within the spinal cord (this transmission leads to excessive muscle tone), which allows for a weakening of muscle tone. [ 2 ]

Pharmacokinetics

Absorption and bioavailability.

The absorption of tizanidine is rapid and almost complete, but due to extensive first-pass metabolic processes, the average bioavailability of the substance is only approximately 34%. Plasma Cmax values are observed after 1 hour from the moment of drug administration. [ 3 ]

Distribution processes.

The average value of the stable distribution volume (Vss) with intravenous administration of the substance is 2.6 l/kg. The protein synthesis rate is 30%.

When the drug is administered in 4-12 mg doses, linear pharmacokinetic parameters are observed. Low variability of AUC and Cmax values between individuals simplifies the process of reliable assessment of plasma levels of LA after oral administration.

Exchange processes.

Tizanidine undergoes extensive intrahepatic metabolism at high speed. Metabolism occurs in vitro mainly with the participation of hemoprotein P4501A2. The metabolic components of tizanidine do not have therapeutic activity.

Excretion.

The final half-life of drug elimination from the circulatory system is on average 2-4 hours. Tizanidine is excreted mainly through the kidneys (approximately 70% of the dosage) in the form of metabolic elements. About 2.7% of the excreted component is unchanged active substance.

In people with renal insufficiency (CC level below 25 ml/min), the Cmax value is 2 times higher than in a healthy person. The final half-life is also prolonged to almost 14 hours, which is why the AUC level also increases (almost sixfold).

Dosing and administration

Adults should take 2-6 mg of the drug 3-4 times a day. The initial dose should not exceed 6 mg 3 times a day. The dosage of the drug is increased gradually, by 2-4 mg, 1-2 times a week.

The medicinal effect usually develops in the case of taking a daily dose of 12-24 mg, divided into 3-4 uses in equal portions. A maximum of 36 mg of the substance is allowed per day.

The duration of therapy is selected individually.

In case of renal/hepatic dysfunctions, the dosage of the drug is reduced. It is necessary to start with a portion of 2 mg, 1 time per day. The dosage should be increased gradually. If there is no effect from the initial portion, first increase the daily dose used for 1 use, and then increase the number of doses.

• Application for children

The drug is not used in pediatrics because there is not enough information regarding its use in children.

Use Tizanidine-ratiopharm during pregnancy

Animal tests have not shown any teratogenic effects. Controlled testing of the drug during pregnancy has not been performed, which is why Tizanidine-ratiopharm is not used during this period (except for cases where the possible benefit of therapy is more likely than any risks).

Experimental tests have shown that small amounts of tizanidine are excreted in milk in animals; the drug is prohibited for use during breastfeeding.

Contraindications

Main contraindications:

• severe intolerance to tizanidine or other components of the drug;
• severe liver dysfunction;
• bulbar syndrome of asthenic type;
• combined use with fluvoxamine or ciprofloxacin.

Side effects Tizanidine-ratiopharm

Side effects include:

• mental disorders: insomnia, sleep problems and hallucinations occasionally develop;
• problems with the functioning of the nervous system: dizziness or drowsiness are often observed;
• disorders of cardiovascular function: a decrease in blood pressure and bradycardia are often observed;
• symptoms related to digestive activity: xerostomia often occurs. Dyspeptic disorders and nausea are occasionally observed;
• lesions of the hepatobiliary system: hepatitis appears sporadically;
• disorders in the area of connective tissues, muscles with bones and joints: muscle weakness occasionally occurs;
• systemic manifestations: increased fatigue is often noted;
• changes in test results: blood pressure often decreases. Serum transaminase levels occasionally increase.

Overdose

Signs of poisoning: vomiting, dizziness, nausea, decreased blood pressure, miosis and coma.

Symptomatic actions are performed.

Interactions with other drugs

It is prohibited to combine the drug with ciprofloxacin or fluvoxamine (each of these drugs slows down the action of human CYP4501A2), because this increases the AUC value of tizanidine (by 10 and 33 times, respectively). As a result, a prolonged, clinically significant decrease in blood pressure values develops, the symptoms of which are dizziness, drowsiness and weakening of psychomotor activity.

Tizanidine-ratiopharm should not be combined with other drugs that inhibit CYP1A2 activity. These include certain antiarrhythmic drugs (mexetin with amiodarone and propafenone), rofecoxib, cimetidine with ticlopidine, certain fluoroquinolones (pefloxacin and norfloxacin with enoxacin, as well as ciprofloxacin) and oral contraception.

Administration together with antihypertensive medications (including diuretics) can lead to bradycardia and a decrease in blood pressure.

Sedatives and alcohol can potentiate the sedative effects of tizanidine.

Storage conditions

Tizanidine-ratiopharm should be stored in a place closed to small children. Temperature indicators - no more than 25°C.

Shelf life

Tizanidine-ratiopharm can be used for a 3-year period from the date of manufacture of the therapeutic product.

Analogues

Analogues of the drug are the drugs Tisalud and Sirdalud.