Pharmacy

Antihypertensive centrally acting drug that stimulates postsynaptic alpha2-adrenergic receptors of the vasomotor center of the medulla oblongata and reduces the flow of sympathetic impulses to the vessels and heart at the presynaptic level. Reduces TPR and IOC, reduces heart rate. With a rapid intravenous injection, a short-term increase in blood pressure is possible due to the stimulation of the postsynaptic alpha1-adrenergic receptors of the vessels. Increases renal blood flow; increasing the tone of the cerebral vessels, reduces cerebral blood flow; has a pronounced sedative effect. The duration of the therapeutic effect is 6-12 hours.

Pharmacokinetics

Absorption after oral administration is fast. Long-term bioavailability is about 65%. TCmax after oral administration - 1.5-2.5 hours, when using TTS - after 2-3 days. The connection with plasma proteins is 20-40%. Easily and quickly penetrates the BBB, placenta and breast milk. Metabolized by the liver (about 50% of the absorbed drug). It is excreted by the kidneys (40-60%) and through the intestines (20%). T1 / 2 -12-16 hours, in case of impaired renal function - up to 41hours.

Indications

• Arterial hypertension (including symptomatic hypertension due to renal pathology),
• hypertensive crisis,
• acute myocardial infarction (in the absence of signs of cardiogenic shock),
• pheochromocytoma (diagnostics),
• headache of vascular origin (prevention),
• dysmenorrhea or menopause (treatment of vasomotor symptoms),
• nicotine addiction,
• Gilles de la Tourette's,
• syndrome withdrawal symptoms in drug addicts (as part of complex therapy).

Dosage

Inside, regardless of food intake, at an initial dose of 0.075 mg 3 times a day. If necessary, the dose is gradually increased to an average daily dose of 0.9 mg. The maximum single dose is 0.3 mg; the maximum daily dose is 2.4 mg.

Elderly patients, especially in the presence of manifestations of cerebrovascular disease, are prescribed in an initial dose of 0.0375 mg 3 times a day.

Cancellation of the drug is carried out gradually, within 1-2 weeks. As a means of preventing headache of vascular genesis: inside, 0.025 mg 2-4 times a day, if necessary, increase the dose to 0.05 mg 3 times a day.

With dysmenorrhea: inside, 0.025 mg 2 times a day for 14 days before and during menstruation.

As an auxiliary drug in the treatment of autonomic symptoms during menopause: inside, 0.025-0.075 mg 2 times a day. For relief of hypertensive crisis - sublingually (in the absence of severe dry mouth) or intravenously or intramuscularly at a dose of 0.15 mg. For intravenous jet injection, 1 ml of the solution is diluted in 10 ml of 0.9% NaCl solution and injected over 7-10 minutes.

For intravenous drip, 4 ml of the solution is diluted in 500 ml of 5% dextrose solution and injected at an average rate of 20 drops / min. The maximum infusion rate is 120 drops / min.

Interaction

Enhances the effect of drugs that depress the central nervous system, and ethanol. The effect is enhanced by other vasodilators, diuretics and antihistamines; weaken - tricyclic antidepressants, anorexigenic drugs (with the exception of fenfluramine - enhances), NSAIDs and sympathomimetics. Beta-blockers and / or cardiac glycosides increase the risk of developing bradycardia and AV block.

Special instructions

At present, clonidine is being displaced from wide practice due to a sharp but short-term decrease in blood pressure followed by a phase of increase in blood pressure ("hemiton crises").

In acute myocardial infarction, as well as for the treatment of vasomotor symptoms against the background of dysmenorrhea or menopause, withdrawal symptoms in drug addicts and the labile course of arterial hypertension, its appointment is especially undesirable. In these cases, imidazoline receptor agonists are preferred.

With long-term parenteral administration of clonidine, it is necessary to regularly monitor intraocular pressure.

To prevent orthostatic hypotension with intravenous injection, the patient should be in a horizontal position during and for 1.5-2 hours after injection.

Development of a weakly positive Coombs reaction is possible. During the treatment period, care must be taken when driving vehicles and engaging in other potentially hazardous activities that require increased concentration of attention and speed of psychomotor reactions.

Side Effects

From the digestive system: dry mouth, decreased appetite, nausea, vomiting, constipation, decreased gastric secretion.

From the nervous system: asthenia, drowsiness, slowing down of the speed of mental and motor reactions, anxiety, nervousness, depression, vivid or "nightmarish" dreams.

From the CVS: bradycardia, orthostatic hypotension; with intravenous administration - increase in blood pressure (short-term).

From the genitourinary system: decreased potency and / or libido. Allergic reactions: skin rash, itching.

Others: Raynaud's syndrome, Na + and water retention, manifested by edema of the feet and ankles, nasal congestion; in case of sudden cancellation - "withdrawal" syndrome, "hemiton crisis".

Overdose. Symptoms (toxic effects can occur in children when taking 0.1 mg): lowering blood pressure or increasing blood pressure (especially in children), bradycardia, widening of the QRS complex, slowing down of AV conduction, early repolarization syndrome, lethargy, miosis, hypothermia, respiratory depression (possibly up to apnea), collapse, impaired consciousness.

Treatment: symptomatic.