Virazone Drug Information [ Rayere Farmaceuticos ]

Table of content

Virazone category:

• Human
• Antivirals
• Nucleosides and Nucleotides

Active ingredients:

• Acyclovir

Virazone companies and manufacturers:

• Rayere Farmaceuticos

General Information

Virazone forms, composition and dosages:

• N / A

Indications, usages and classification codes:

• D06BB03 - Aciclovir
• J05AB01 - Acyclovir

There is an additional general information about this medication active ingredient acyclovir:

Pharmacological action

Antiviral agent. Thymidine kinase of virus-infected cells actively converts acyclovir through a series of sequential reactions in the mono-, di- and triphosphate of acyclovir. The latter interacts with the viral DNA polymerase, and embedded in DNA, which is synthesized for new viruses. Thus it is formed a "defective" viral DNA which leads to suppression of replication of new generations of viruses.
This mediciine acyclovir is active against Herpes Simplex virus types 1 and 2, Varicella Zoster virus, Epstein-Barr virus and cytomegalovirus.

Pharmacokinetics

For oral administration bioavailability is 15-30%. Widely distributed in tissues and body fluids. Plasma protein binding is 9-33%. Metabolised in liver. T_1/2 for oral administration - 3.3 h, intravenous - 2.5 hours; acyclovir excreted in the urine, also in small quantities - with feces.

Why is Virazone prescribed?

For systemic use (oral and IV): infections caused by Herpes Simplex virus types 1 and 2 and Varicella Zoster; prevention of infections caused by viruses Herpes Simplex and Varicella Zoster (including in patients with low immunity); in combined therapy with the pronounced immunodeficiency (including in the clinical picture of HIV infection) and in patients undergoing marrow transplantation, prevention of cytomegalovirus infection after marrow transplantation.
For topical use in ophthalmology: keratitis and other eye damage caused by Herpes Simplex virus.
For external use: infections of the skin caused by Herpes Simplex virus and Varicella Zoster like Herpes Simplex of the skin and mucous membranes, genital herpes (primary and recurrent) localized zoster (support therapy).

Dosage and administration

For oral usage for adults and children older than 2 years - 200-400 mg of 3-5 times / day, if necessary - to 20 mg / kg (up to 800 mg per dose) 4 times / day. For children under 2 years are used in doses equal to half the adult dose. Duration of treatment - 5-10 days. In renal insufficiency is recommended correction dosing regimen.
IV in adults and children over 12 years - 5-10 mg / kg, the interval between infusions - 8 hours. Children under the age of 3 months to 12 years - 250-500 mg / m2 body surface, the interval between infusions - 8 hours, for infants dose is 10 mg / kg, the interval between infusions - 8 hours.
In renal insufficiency must be corrected dosing regimen.
Locally and externally applied 5 times / 24 h. Dose and duration of treatment depends on the testimony and the use of dosage form.
Maximum dose for adults for IV usage is 30 mg / kg / 24 h.

Virazone side effects

For oral usage: nausea, vomiting, diarrhea, abdominal pain, skin rash, headache, dizziness, fatigue, reduced concentration, hallucinations, drowsiness or insomnia, fever, rarely - hair loss, a transient increase in blood concentrations of bilirubin, urea, creatinine, liver enzymes, lymphocytopenia, eritropeniya, leukopenia.
For IV usage: acute renal failure, crystalluria, encephalopathy (confusion, hallucinations, agitation, tremors, convulsions, psychosis, drowsiness, coma), phlebitis, or inflammation at the injection site, nausea, vomiting.
For topically usage: a burning sensation in the application area, superficial punctate keratitis, blepharitis, conjunctivitis.
For external usage: in the application area may be a burning sensation, skin rash, itching, peeling, erythema, dry skin in contact with mucous membranes - inflammation.

Contraindications

Hypersensitivity to acyclovir and valaciclovir; for IV usage - lactation (breast feeding).

Using during pregnancy and breastfeeding

Pregnancy. Perhaps, if the expected effect of the therapy outweighs the potential risk to the fetus (adequate and strictly controlled studies of safety in pregnant women is not conducted); acyclovir passes through the placenta. Data on the outcome of pregnancy in women taking acyclovir systemic action in the I trimester of pregnancy showed no increase in birth defects compared with the total population. Since the observation was included a small number of women, reliable and definitive conclusions about the safety of acyclovir in pregnancy can be done.
Breastfeeding. acyclovir penetrates into breast milk. After taking acyclovir by mouth, it was determined in breast milk in concentrations, the ratio of which, with concentrations in blood plasma was 0,6-1,4. At these concentrations in breast milk, children who are breastfed can receive acyclovir at a dose of 0.3 mg / kg / day. Given this, should appoint acyclovir lactating women with caution, only if necessary.

Special instructions

Do not use with severely impaired renal function.
Note that the application of acyclovir may develop acute renal failure due to precipitate formation of crystals of acyclovir, which is especially likely during rapid IV introduction, the simultaneous use of nephrotoxic drugs in patients with impaired renal function and lack of water stress.
When applying aciclovir should monitor renal function (determination of the level in the blood urea nitrogen and creatinine in blood plasma).
Treatment of elderly patients should be conducted with a sufficient increase in water load and under the supervision of a physician, because among these patients increased half-life of acyclovir.
In the treatment of genital herpes should avoid sex or use condoms, because use of acyclovir does not prevent transmission to partners.
This medication acyclovir in the form of dosage forms for topical use should not be applied to mucous membranes of the mouth, eyes, vagina.

Virazone drug interactions

With simultaneous use of probenecid decreases the tubular secretion of acyclovir, and thereby increases the concentration in blood plasma and the half-life of acyclovir.
With simultaneous use of acyclovir with other nephrotoxic drugs increases the risk of nephrotoxicity (especially in patients with impaired renal function).
Enhancing effect of acyclovir is noted while appointing immunostimulators.
When mixed solutions should be considered an alkaline reaction to acyclovir for IV introduction (pH 11).

Virazone in case of emergency / overdose

Symptoms: headache, neurological disorders, shortness of breath, nausea, vomiting, diarrhea, renal failure, lethargy, convulsions, coma.
Treatment: symptomatic therapy, the maintenance of vital functions, adequate hydration, hemodialysis (especially in acute renal failure and anuria). There is no data for overdose when applied topically.

• Virazone analogs
• Virazone similar