- Diazepam is rapidly absorbed from the digestive tract, reaching C max in plasma within about 30–90 minutes. The degree of absorption is high (75%).
- Diazepam binds to plasma proteins (98–9%), dissolves well in lipids, and easily crosses the BBB and the placental barrier.
- The drug also passes into breast milk. The apparent volume of distribution is 1–2 l / kg body weight.
- The drug is metabolized in the liver with the formation of active metabolites – N-desmethyldiazepam, temazepam and oxazepam.
- T ½ diazepam – up to 24 hours. T ½ of the main metabolite of diazepam – N-desmethyldiazepam – can reach 100 hours, and therefore the therapeutic effect of the drug is lengthened. Diazepam and its metabolites are excreted mainly in the urine, mainly in the form of conjugates.
- The clearance of diazepam is 20-30 ml / min.
- With repeated use, diazepam accumulates in the body. T ½ increases in newborns, the elderly and patients with liver diseases; with renal failure, small changes.
Injection
- Absorption . The absorption of diazepam depends on its route of administration. With a / m administration, the drug is completely absorbed, however, diazepam is not always absorbed faster than when administered orally.
- Distribution . The level of binding of diazepam and its metabolites to plasma proteins is high (diazepam – 98%). Diazepam is known to be highly soluble in lipids. Diazepam and its metabolites penetrate the BBB and placental barrier and into breast milk (approximately 1 / 10 concentration in the mother’s plasma).
- Metabolism . Diazepam is metabolized mainly in the liver with the formation of pharmacologically active metabolites – N-desmethyldiazepam, temazepam, oxazepam.
- Breeding . Elimination of diazepam consists of two phases. The first phase indicates its rapid spread in the body, the second phase indicates prolonged excretion, which lasts 1-2 days.
- T ½ of the drug can last 2–5 days, as its active metabolite, desmethyldiazepam (nordiazepam), circulates in the body.
Pharmacokinetics in special clinical cases . T ½ of diazepam and its metabolites increases in newborns, the elderly and in patients with liver diseases. In renal failure, T ½ remains virtually unchanged.
Intramuscular injections can cause an increase in plasma CPK activity when the maximum level is reached 12-24 hours after administration. This should be taken into account in the differential diagnosis of myocardial infarction.
Absorption during i / m administration is variable (especially from the gluteal muscles). This method of administration should be used if oral or iv administration is not possible or not recommended.
The relationship between the concentration of diazepam and its metabolites in blood plasma and therapeutic effect is absent.
INDICATIONS
- For short-term treatment of anxiety, anxiety and insomnia.
- To stop muscle cramps and pain associated with a local pathological process or cerebrospinal diseases.
- To prevent a spasmodic condition and relapse of seizures.
- In the case of alcohol withdrawal syndrome.
- For sedation during surgical operations.
Injection
- Conditions of anxiety and fear or their symptoms.
- Alcohol withdrawal syndrome.
- Convulsions of various etiologies, epileptic status, febrile convulsions.
- The drug is also used for sedation before surgery.
Contraindications
- Hypersensitivity to benzodiazepines in the anamnesis.
- An acute attack of angle-closure glaucoma or open-angle glaucoma if the patient does not receive appropriate therapy.
- Myasthenia gravis.
- Respiratory depression, acute respiratory failure.
- Sleep apnea.
- Severe liver failure.
- Intoxication with drugs and psychotropic substances.
- Alcohol intoxication, acute intoxication with substances that depress the central nervous system.
- The first 30 days of life of newborns due to liver failure.
- I and III trimester of pregnancy.
- The period of breastfeeding.
- Not intended for the treatment of phobias, obsession, and chronic psychoses.
- It can not be used in the form of monotherapy for the treatment of depression or depression associated with anxiety, fear, because such patients may experience suicidal tendencies.
Side effects
- very often (≥1 / 10), often (≥1 / 100 to <1/10), infrequently (≥1 / 1000 to < 1/100), rarely (≥1 / 10,000 to <1/1000),
- very rarely (<1/10 000), with an unknown frequency (cannot be determined from the available data).
From the nervous system :
- often – drowsiness; rarely – coordination disorders,
- headache,
- dizziness,
- tremor,
- fainting,
- vertigo, amnesia,
- dysarthria,
- immobility.
From the psyche :
- rarely – confusion,
- depression,
- nervousness,
- paranoia,
- oppressed or increased sex drive,
- addiction syndrome;
- paradoxical reactions (for example, an acute state of anxiety, fear, hallucinations, increased muscle tone, insomnia or sleep disturbances, nightmares, aggressiveness, inappropriate behavior).
From the digestive tract :
- rarely – constipation,
- nausea,
- changes in the activity of the salivary glands,
- increased salivation.
From the side of the organ of vision :
- rarely – blurred vision,
- diplopia,
- nystagmus.
From the cardiovascular system :
- rarely – arterial hypotension,
- bradycardia,
- cardiovascular collapse;
- very rarely – cardiac arrest.
From the urinary system :
- rarely – incontinence, urinary retention.
On the part of the skin :
- rarely – urticaria, rashes.
From the respiratory system :
- rarely – shortness of breath, apnea.
From the hepatobiliary system :
- very rarely – jaundice.
From the blood system :
- very rarely – neutropenia.
Laboratory indicators :
- very rarely – increased activity of transaminases and alkaline phosphatase.
General disorders and reactions at the injection site :
- often – increased fatigue; the frequency is unknown – thrombosis and thrombophlebitis at the injection site; local pain, erythema, sensitivity at the injection site (in the case of i / m administration), hiccups.
- To reduce the risk of thrombophlebitis and vein thrombosis, injection should not be made into small veins. Injections into arteries or peri-vascular space should especially be avoided.
- Elderly people and patients with impaired liver function are more sensitive to the aforementioned adverse effects. It is recommended to regularly review therapy and, if necessary, discontinue use as soon as possible.
STORAGE CONDITIONS
- tablets – at a temperature not exceeding 25 ° C;
- injection solution – in the refrigerator at a temperature of 2–8 ° С.