Gutron (Tablets, Drops) Instructions for Use

ATC Code

C01CA17 (Midodrine)

Active Substance

Midodrine (Rec.INN)

Clinical-Pharmacological Group

Alpha-adrenergic agonist

Pharmacotherapeutic Group

Alpha-adrenomimetic

Pharmacological Action

Alpha-adrenomimetic. It selectively stimulates the peripheral alpha-adrenergic receptors of the sympathetic nervous system. It causes an increase in vascular tone, which, in turn, increases the total peripheral vascular resistance, raises blood pressure and prevents (in orthostatic disorders) blood stagnation in the venous circle.

As a result, the circulating blood volume and blood pressure are maintained at a constant level, the blood supply to organs increases, and thereby orthostatic reactions are eliminated (including morning weakness and fatigue, frequent yawning, dizziness).

It does not affect heart activity, but a reflex decrease in heart rate is possible. It does not increase the excitability of the central nervous system.

By stimulating the alpha-adrenergic receptors located in the bladder sphincter and urethra, Midodrine increases their tone and has a therapeutic effect in involuntary urination.

Pharmacokinetics

After oral administration, it is well absorbed. The absolute bioavailability is 93% and does not depend on food intake. It has very low lipophilicity and does not penetrate the blood-brain barrier. Binding to plasma proteins is partial. It is detected in plasma within 10 minutes, and the maximum concentration in the blood is reached in 1-2 hours.

In the body, it is deglycinated to form the active metabolite desglymidodrine and aminoacetic acid; desglymidodrine is formed in many tissues and has a significantly stronger vasoconstrictive (sympathomimetic) effect. The final metabolism occurs in the liver.

After oral and intravenous administration, the elimination half-life from plasma is 3-4 hours. Midodrine and its metabolites are completely excreted by the kidneys within 24 hours, about 40% as the active metabolite, 5% unchanged, and about 55% as pharmacologically inactive metabolites.

Indications

Orthostatic disorders of vascular tone regulation, constitutional hypotension, symptomatic hypotension (including during convalescence, after surgery, childbirth); hypotensive lability with weather changes, morning weakness and feeling of fatigue; involuntary urination due to bladder sphincter dysfunction.

ICD codes

Dosage Regimen

Administer orally or intravenously as directed. The dosage, route, and schedule must be individualized based on indication and disease severity.

For orthostatic hypotension, the typical adult oral dose is 2.5 mg to 5 mg taken two to three times daily. Administer doses during daytime hours when the patient is upright and active.

Take the last daily dose no later than 6 PM or at least 4 hours before bedtime to minimize the risk of supine hypertension. Monitor blood pressure in both supine and standing positions regularly.

For involuntary urination due to sphincter dysfunction, follow the dosage prescribed by a physician, typically within the same range. Titrate the dose gradually to achieve the desired clinical effect while minimizing adverse reactions.

Do not exceed the maximum recommended daily dose of 30 mg. Use caution in patients with renal or hepatic impairment; a dose reduction may be necessary. For pediatric use, the dose must be determined by a physician based on body weight.

Adverse Reactions

From the cardiovascular system: increased blood pressure (including when lying down), facial flushing, bradycardia.

From the urinary system: urination disorder (increased frequency or retention).

From the nervous system: headache, dizziness, insomnia, drowsiness, asthenia, paresthesia.

From the digestive system: heartburn, dry mouth, nausea, dyspepsia, flatulence.

Dermatological reactions: sweating, pilomotor reaction (“goosebumps”), skin itching, chills.

Contraindications

Hypersensitivity to midodrine; arterial hypertension, pheochromocytoma, obliterating arterial diseases, acute nephritis, severe renal failure, angle-closure glaucoma, benign prostatic hyperplasia with residual urine, mechanical obstruction of the urinary tract, hyperthyroidism.

Use in Pregnancy and Lactation

If it is necessary to use midodrine during pregnancy and lactation (breastfeeding), the expected benefit of therapy for the mother and the potential risk to the fetus or infant should be weighed.

Use in Hepatic Impairment

It should be used with caution in patients with hepatic insufficiency.

Use in Renal Impairment

Contraindicated in acute nephritis, severe renal failure.

It should be used with caution in patients with chronic renal failure. During long-term therapy, renal function should be monitored.

Geriatric Use

It should be prescribed with caution to elderly patients to avoid worsening of concomitant diseases.

Special Precautions

It should be used with caution in patients with chronic heart failure, renal and/or hepatic insufficiency, and cardiac rhythm disorders.

During long-term therapy, renal function should be monitored.

With simultaneous use with other drugs that have a direct or indirect effect on blood pressure or heart rate (including with guanethidine, beta-blockers), careful monitoring of blood pressure and heart rate is required.

Special attention when selecting doses is necessary for patients with arterial hypertension and hypotensive lability with weather changes.

It is prohibited for use in athletes (refers to doping drugs).

Drug Interactions

With simultaneous use with cardiac glycosides, the development of reflex bradycardia, as well as disturbances of intracardiac conduction, is possible.

With simultaneous use with atropine, cortisone, an increase in the hypertensive effect is possible.

With simultaneous use with alpha-blockers (prazosin, phentolamine, reserpine), the effect of midodrine, like other alpha-adrenomimetics, may be reduced or completely eliminated.

Storage Conditions

Store at 2°C (36°F) to 25°C (77°F). Keep in original packaging, protected from light. Keep out of reach of children.

Dispensing Status

Rx Only

Important Safety Information

This information is for educational purposes only and does not replace professional medical advice. Always consult your doctor before use. Dosage and side effects may vary. Use only as prescribed.