Rimantadine Actitab, tablets 50 mg 20 pcs

Pharmaceutical group:

an antiviral agent.

Pharmic action:

Rimantadine Actitab is an antiviral agent, an adamantane derivative; effective against strains of influenza A virus, Herpes simplex viruses type I and II, tick-borne encephalitis viruses (Central European and Russian spring and summer from the Arbovirus family. Flaviviridae).

It has antitoxic and immunomodulatory action. Polymeric structure provides long-term circulation of rimantadine in the body which allows to use it not only for treatment but also for preventive purposes.

As a weak base, it increases pH of endosomes having the membrane of vacuoles and surrounding viral particles after their penetration into the cell. Preventing acidification in these vacuoles blocks the fusion of the viral envelope with the endosome membrane, thus preventing the transfer of viral genetic material into the cell cytoplasm. Rimantadine also inhibits the exit of viral particles from the cell, i.e. it interrupts the transcription of the viral genome.

The prophylactic administration of rimantadine in a daily dose of 200 mg reduces the risk of influenza and also reduces the severity of flu symptoms and serological response. Some therapeutic effect may also occur when it is administered in the first 18 hours after the development of the first flu symptoms.

Pharmacokinetics:

After oral administration, it is almost completely absorbed in the intestine. Absorption is slow. Time to reach maximum concentration (TCmax) – 1-4 hours. Binding to plasma proteins is about 40%. Volume of distribution: adults – 17-25 l/kg, children – 289 l. Concentration in nasal secretion is 50% higher than in plasma.

The value of maximum concentration (Cmax) in administration of 100 mg once daily is 181 ng/ml, in 100 mg twice daily – 416 ng/ml. It is metabolized in the liver. Period of half-life (T1/2) in adults 20-44 years old – 25-30 h, in elderly patients (71-79 years old) and in patients with chronic liver failure – about 32 h, in children 4-8 years old – 13-38 h; more than 90% is excreted by kidneys during 72 hours, mainly as metabolites, 15% – unchanged.

In chronic renal insufficiency (CKD) T1/2 is increased by 2 times. In persons with renal insufficiency and in the elderly it may accumulate in toxic concentrations if the dose is not adjusted in proportion to the decrease in creatinine clearance (CK). Hemodialysis has little effect on rimantadine clearance.

Indications

Active ingredient

Composition

How to take, the dosage

Orally (after meals) with water, according to the following scheme:

Adults are prescribed on the first day of the disease in 100 mg 3 times; on the second and third days, 100 mg 2 times; on the fourth day 100 mg once. On the first day of the disease it is possible to use the drug once in a dose of 300 mg.

Children from 7 to 10 years are prescribed 50 mg 2 times a day; 11-14 years 50 mg 3 times a day. Influenza A treatment should be started within 24-48 hours after the onset of symptoms and continued for 5-7 days. The optimal duration has not been established.

For prevention of influenza in adults, 50 mg once a day for 10-15 days, depending on the focus of infection.

For treatment of influenza in patients with CKD (CKD less than 10 ml/min), severe hepatic failure, elderly patients in nursing homes – 100 mg once a day.

Interaction

When used concomitantly, rimantadine reduces the effectiveness of antiepileptic drugs.

Adsorbents, astringents and coating agents decrease absorption of rimantadine.

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

The agents that alkalize the urine (acetazolamide, sodium bicarbonate) increase its effectiveness (decrease its excretion by the kidneys).

Paracetamol and acetylsalicylic acid decrease Cmax of rimantadine by 11%.

Cimetidine decreases clearance of rimantadine by 18%.

Special Instructions

In comparison with amantadine it has higher clinical efficacy and is less toxic.

The appearance of viruses resistant to the drug is possible.

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

When using rimantadine, exacerbation of chronic comorbidities is possible. In elderly patients with arterial hypertension, the risk of hemorrhagic stroke increases. In patients with a history of epilepsy and anticonvulsant therapy during rimantadine use, the risk of an epileptic seizure increases. In such cases, rimantadine is used in dose of 0.1 g per day simultaneously with anticonvulsant therapy.

The prophylactic administration is effective in case of contact with ill people (administration of the drug is necessary for at least 10 days after contact), when the infection spreads in closed groups and at high risk of the disease during the flu epidemic.

At the time of treatment, caution should be exercised when driving a vehicle and engaging in other potentially dangerous activities that require increased concentration and quick psychomotor reactions.

Contraindications

– Hypersensitivity to rimantadine.
– Acute liver diseases;
– Acute and chronic kidney diseases;
– Thyrotoxicosis;
– Pregnancy and lactation period;
– Childhood (under 7 years):

Arterial hypertension, epilepsy (including. including in anamnesis), cerebral atherosclerosis, chronic renal insufficiency, hepatic insufficiency.

Side effects

Digestive system disorders: epigastric pain, flatulence, increased bilirubin level in blood, dry mouth, anorexia, nausea, vomiting, gastralgia.

CNS disorders: headache, insomnia, nervousness, dizziness, concentration disorders, drowsiness, anxiety, increased excitability, fatigue.

Others: allergic reactions.

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