Tabex® [Cytisine]

Pharmacological properties

Mechanism of action. cytisine is an alkaloid that is obtained from the plant cytisus laburnum.

It has a chemical structure similar to that of nicotine and lobelin. It selectively and competitively binds to receptors, possessing partial agonistic activity against nicotinic acetylcholine receptors and, in particular, high affinity for the α4β2 subtype. Thus, it prevents the binding of nicotine to α4β2 receptors and the stimulation of the central mesolimbic dopamine system associated with the mechanisms of nicotine addiction due to the ability of nicotine to activate these receptors.

Pharmacodynamics The effect of the drug consists in the excitation of the ganglia of the autonomic nervous system, the excitation of respiration in the reflex way, the release of adrenaline from the medullary part of the adrenal glands, and an increase in blood pressure. The mechanism of action of cytisine is similar to the mechanism of action of nicotine, but with much less toxicity and greater therapeutic effect. Cytisine competitively inhibits the interaction of nicotine with the corresponding receptors, which leads to a gradual decrease and disappearance of nicotine addiction.

Pharmacokinetics Absorption: cytisine is rapidly absorbed in the gastrointestinal tract after oral administration. Plasma C_max - 15.55 ng / ml is achieved within 0.92 hours

Distribution: there is no data on the volume of distribution in humans.

Biotransformation and excretion: cytisine is not metabolized in the body. Up to 64% of the applied dose is excreted unchanged in the urine within 24 hours. T_½ is approximately 4 hours. The average retention time (MRT) of cytisine in the body is approximately 6 hours.

Indications

Tabex is prescribed for chronic nicotinism for smoking cessation.

Application

Adults the drug is used according to the following scheme: from the 1st to the 3rd day - 1 tablet every 2 hours (6 tablets per day). at the same time, the number of cigarettes smoked is gradually reduced. if the result is unsatisfactory, treatment is discontinued and can be resumed after 2-3 months. with a positive effect, therapy is continued according to this scheme:

• from the 4th to the 12th day - 1 tablet every 2.5 hours (5 tablets per day);
• from the 13th to the 16th day - 1 tablet every 3 hours (4 tablets per day);
• from the 17th to the 20th day - 1 tablet every 5 hours (3 tablets per day);
• from the 21st to the 25th day - 1-2 tablets per day.

The tablets are taken whole, washed down with a sufficient amount of liquid.

The final cessation of smoking should occur by the 5th day from the start of treatment. After completing treatment, the patient should exercise willpower and not allow himself to smoke a single cigarette.

Duration of treatment - according to the scheme.

Patients over the age of 65. It is not recommended to use the drug in this age group of patients.

Contraindications

Tabex is contraindicated in case of hypersensitivity to the active or any of the excipients of the drug, with acute myocardial infarction, unstable angina, cardiac arrhythmia, recent cerebrovascular disease, atherosclerosis; severe ag, during pregnancy and lactation.

Side effects

The drug is usually well tolerated. mild to moderate side effects are rarely possible. most of them appear at the beginning and disappear during treatment. most often they are associated with smoking cessation and are manifested by dizziness, headache and insomnia.

From the endocrine system: increased sweating, weight loss.

From the nervous system: headache, dizziness, insomnia, drowsiness, increased irritability.

From the side of the heart: tachycardia, palpitations.

From the vessels: a slight increase in blood pressure.

From the respiratory system, chest and mediastinal organs: dyspnea.

From the digestive system: change in taste and appetite, dry mouth, abdominal pain, nausea, constipation, diarrhea, pain in the upper abdomen, dyspepsia, vomiting.

From the musculoskeletal system and connective tissue: myalgia.

General disorders and disorders at the injection site: chest pain.

special instructions

Tabex should only be used if the patient intends to seriously quit smoking. the use of the drug and simultaneous smoking can lead to increased side effects of nicotine (to nicotine intoxication).

There is insufficient clinical experience with the use of Tabex in patients with coronary heart disease, heart failure, hypertension, cerebrovascular disease, arterial obliterans, hyperthyroidism, peptic ulcer of the stomach, diabetes mellitus, renal or liver failure. The drug should be prescribed to these categories of patients only after a thorough assessment by the doctor of the benefit / risk ratio.

Due to the lack of appropriate studies on the safety of the drug in patients with some forms of schizophrenia, patients with chromaffin adrenal tumors and gastroesophageal reflux disease, it is possible only after a thorough assessment of the benefit / risk ratio.

There is insufficient clinical experience regarding the safe use of Tabex in children (under the age of 18) and the elderly (over 65), therefore, its use in these age groups is not recommended.

During pregnancy and lactation, the use of the drug is contraindicated.

Children. Do not use in children.

The ability to influence the reaction rate when driving vehicles or working with other mechanisms. The use of Tabex does not usually affect the reaction rate when driving vehicles or working with other mechanisms.

Given that it is rare for sensitive patients when using the drug to experience adverse reactions (drowsiness, dizziness), at the beginning of treatment should refrain from driving vehicles and working with other mechanisms.

Interactions

When smoking, there is an increased activity of cyp 1a2. after the cessation of smoking, the activity of this isoenzyme may decrease, which may cause an increase in plasma concentrations of drugs that are metabolized by cyp 1a2, for example, theophylline, ropinirole, clozapine and olanzapine. in these cases, their adverse reactions may intensify, since these drugs have a small breadth of therapeutic effect.

With the simultaneous use of Tabex drug with cholinomimetics and anticholinesterase drugs, it is possible to increase cholinomimetic side effects.

Concomitant use with antihyperlipidemic drugs (statins) increases the risk of myalgia.

The simultaneous use of Tabex with antihypertensive drugs can weaken their effect.

Overdose

Symptoms: nausea, vomiting, profuse sweating, tremors, blurred vision, general weakness, tachycardia, clonic convulsions, respiratory paralysis.

Treatment: gastric lavage, if the patient is conscious, the infusion of water-salt solutions, anticonvulsants, cardiotonic, analeptic and other symptomatic agents are used. Monitor respiration, blood pressure and heart rate.

Storage conditions

In the original packaging for protection against moisture, at a temperature not exceeding 25 ° C.