Rimantadine, tablets 50 mg 20 pcs

Pharmacotherapeutic group: Antiviral drug.
ATX code: J05AC02

Pharmacological properties:

Pharmacodynamics
Rimantadine is an antiviral agent, an adamantane derivative; active against various shiampas of influenza A virus (especially type A2).
A weak base, the drug Rimantadine acts by increasing the pH of endosomes, which have a membrane of vacuoles that surround viral particles after their penetration into the cell. Preventing acidification in these vacuoles blocks the fusion of the viral membrane with the endosome membrane, thus preventing the transfer of viral genetic material into the cell cytoplasm. The drug Rimantadine also inhibits exit of viral particles from the cell, i.e. it interrupts transcription of the viral genome.

Pharmacokinetics
After oral administration, the drug Rimantadine is almost completely absorbed in the intestine.
Absorption is slow. Binding to plasma proteins is about 40%. Distribution volume: adults – 17-25 l/kg, children – 289 l/kg. Concentration in nasal secretion is 50% higher than plasma concentration. Maximal concentration of preparation Rimantadine in plasma (Сmax) when administered by 100 mg once daily – 181 ng/ml, by 100 mg twice daily – 416 ng/ml.
Metabolized in liver. Half-life period (T1/2) – 24-36 hours; excreted by kidneys – 15% unchanged, 75-85% – as metabolites.
The T1/2 in chronic renal insufficiency is increased twice. In patients with renal insufficiency and elderly patients it may accumulate in toxic concentrations if the dose is not corrected in proportion to the decrease of creatinine clearance.

Indications

Early treatment and prevention of influenza A in adults and children over 7 years of age.

Pharmacological effect

Pharmacotherapeutic group: Antiviral agent.
ATX code: J05AC02

Pharmacological properties:

Pharmacodynamics
Rimantadine is an antiviral agent, an adamantane derivative; is active against various influenza A virus strains (especially A2 type).
Being a weak base, the drug Rimantadine acts by increasing the pH of endosomes, which have a membrane of vacuoles that surround viral particles after they penetrate the cell. Preventing acidification in these vacuoles blocks the fusion of the viral envelope with the endosome membrane, thereby preventing the transfer of viral genetic material into the cell cytoplasm. The drug Rimantadine also inhibits the release of viral particles from the cell, i.e. interrupts transcription of the viral genome.

Pharmacokinetics
After oral administration, the drug Rimantadine is almost completely absorbed in the intestine.
Absorption is slow. Communication with plasma proteins is about 40%. Volume of distribution: adults – 17–25 l/kg, children – 289 l/kg. The concentration in nasal secretions is 50% higher than the plasma concentration. The maximum concentration of the drug Rimantadine in blood plasma (Cmax) when taken 100 mg 1 time per day is 181 ng/ml, 100 mg 2 times a day is 416 ng/ml.
Metabolized in the liver. Half-life (T1/2) – 24–36 hours; 15% is excreted by the kidneys – unchanged, 75-85% – in the form of metabolites.
In chronic renal failure, T1/2 increases by 2 times. In persons with renal insufficiency and in the elderly, toxic concentrations may accumulate if the dose is not adjusted in proportion to the decrease in creatinine clearance.

Special instructions

Rimantadine is used with caution in cases of arterial hypertension, epilepsy (including a history), and cerebral atherosclerosis.

When using rimantadine, exacerbation of chronic concomitant diseases is possible. Elderly patients with arterial hypertension have an increased risk of developing hemorrhagic stroke. If there is a history of epilepsy and anticonvulsant therapy, the risk of developing an epileptic seizure increases with the use of rimantadine. In such cases, rimantadine is used at a dose of up to 100 mg/day simultaneously with anticonvulsant therapy.

For influenza caused by virus B, rimantadine has an antitoxic effect.

Prophylactic administration is effective during contacts with sick people, during the spread of infection in closed groups and at a high risk of developing the disease during an influenza epidemic. Viruses resistant to the drug may emerge.

Active ingredient

Rimantadine

Composition

Active ingredient: rimantadine hydrochloride – 50.0 mg.
Excipients: lactose monohydrate – 74.50 mg, potato starch – 22.57 mg, talc – 1.50 mg, calcium stearate – 1.43 mg.

Contraindications

Acute liver diseases,
acute and chronic kidney diseases,
thyrotoxicosis,
hypersensitivity to rimantadine,
pregnancy and lactation period,
children under 7 years old,
for lactase deficiency, lactose intolerance, lactose/isomaltose malabsorption syndrome (since the drug contains lactose).
With caution: with arterial hypertension, cerebral atherosclerosis, liver failure, epilepsy, diseases of the gastrointestinal tract.

Side Effects

From the digestive system: epigastric pain, flatulence, increased bilirubin levels in the blood, dry mouth, anorexia, nausea, vomiting, gastralgia.

From the side of the central nervous system: headache, insomnia, nervousness, dizziness, impaired concentration, drowsiness, anxiety, increased excitability, fatigue.

Other: allergic reactions.

Interaction

With simultaneous use, rimantadine reduces the effectiveness of antiepileptic drugs.

Adsorbents, astringents and coating agents reduce the absorption of rimantadine.

Agents that acidify urine (ammonium chloride, ascorbic acid) reduce the effectiveness of rimantadine (due to increased excretion by the kidneys).

Agents that alkalize urine (acetazolamide, sodium bicarbonate) enhance its effectiveness (reduced excretion by the kidneys).

Paracetamol and acetylsalicylic acid reduce the Cmax of rimantadine by 11%.

Cimetidine reduces the clearance of rimantadine by 18%.

Overdose

Symptoms: agitation, hallucinations, arrhythmia.

Treatment: gastric lavage, symptomatic therapy: measures to maintain vital functions. Rimantadine is partially eliminated by hemodialysis.

Storage conditions

In a dry place, protected from light, at a temperature not exceeding 25 ° C.
Keep out of the reach of children.

Shelf life

2 years. Do not use after the expiration date stated on the package.

Manufacturer

Pharmstandard-Leksredstva, Russia