Description of the active substance:
This information is a reference and it is not enough that the drug has been prescribed by a doctor ..
Anti-tuberculosis drug I of the series. Has a bactericidal effect. Isoniazid is active against extracellular and intracellular Mycobacterium tuberculosis, especially in relation to actively dividing. The exact mechanism of its action is unknown. It is assumed that it is associated with the suppression of the synthesis of mycolic acids, which are part of the cell wall of mycobacteria.
After oral administration, it is rapidly absorbed from the digestive tract. When taken with food, absorption and bioavailability decrease. Widely distributed in all tissues and body fluids. Binding to plasma proteins is very low (0-10%). Metabolised in the liver. It is excreted in the urine, a small amount - with feces.
Treatment of all forms of active tuberculosis, incl. tuberculous meningitis (as part of combination therapy). Prevention of tuberculosis in persons in close contact with patients with tuberculosis; in persons with a positive skin reaction (more than 5 mm) per tuberculin and X-ray data indicating non-progressive tuberculosis; in children younger than 4 years with a positive reaction to tuberculin (more than 10 mm) and an increased risk of dissemination.
The dose is set individually, depending on the nature and form of the disease.
Inside adults and adolescents - 300 mg 1 time / day or 15 mg / kg / day 2-3 times a week (as determined by the scheme of therapy), children - 10-20 mg / kg 1 time / day or 20-40 mg / kg 2-3 times a week (as determined by the therapy regimen).
In / m adults and adolescents enter 5 mg / kg 1 time / day or 15 mg / kg 2-3 times / week, children - 10-20 mg / kg 1 time / day or 20-40 mg / kg 2-3 times a week.
The duration of treatment is determined individually.
Intracavernosis is administered in a daily dose of 10-15 mg / kg. At inhalations - 5-10 mg / kg / day in 1-2 reception.
The maximum daily intake for adults with oral and / or induction is 300 mg.
From the side of the central nervous system and peripheral nervous system: headache, dizziness; rarely - psychosis, euphoria, sleep disturbances, peripheral neuritis.
On the part of the digestive system: nausea, vomiting, drug-induced hepatitis.
From the cardiovascular system: pain in the heart.
On the part of the endocrine system: very rarely - gynecomastia in men, menorrhagia in women.
Allergic reactions: skin rash, itching.
Epilepsy, convulsive seizures and poliomyelitis in history, impaired liver and / or kidney function, atherosclerosis.
PREGNANCY AND LACTATION
Possible use of isoniazid in pregnancy and lactation (breastfeeding).
Isoniazid penetrates the placental barrier, excreted in breast milk.
APPLICATION FOR FUNCTIONS OF THE LIVER
Contraindicated in the violation of kidney function.
APPLICATION FOR VIOLATIONS OF THE FUNCTION OF KIDNEYS
Contraindicated in the violation of liver function.
It is not recommended to use isoniazid in a dose of more than 10 mg / kg for severe forms of cardiopulmonary insufficiency and / or hypertension, IHD, advanced atherosclerosis, diseases of the nervous system, bronchial asthma, psoriasis, eczema in the exacerbation phase, myxedema.
To avoid the rapid development of the resistance of Mycobacterium tuberculosis, isoniazid is used in combination with other anti-tuberculosis drugs.
After the injection, the patient must comply with bed rest for 1-1.5 hours.
To reduce the side effects concomitant with isoniazid prescribed pyridoxine (inside or / m), or glutamic acid (inward), or thiamine (IM).
It should be noted that isoniazid is metabolized in the liver by acetylation to inactive metabolites. The degree of acetylation is determined by genetic factors. In connection with the unequal degree of metabolism before the use of isoniazid, it is expedient to determine the rate of its inactivation by the content of the active substance in the blood and urine. In patients with rapid inactivation, isoniazid is used in higher doses.
With simultaneous use with rifampicin, the risk of hepatotoxicity increases (especially in patients with impaired hepatic function).
At simultaneous application with paracetamol the risk of development of a hepatotoxic action increases, since. isoniazid induces cytochrome P450, which leads to an increase in the content of toxic metabolites of paracetamol.
With the simultaneous use of isoniazid with carbamazepine or phenytoin, the metabolism of the latter is suppressed, which leads to an increase in their concentrations in the blood plasma and an increase in the toxic effect.