The antiviral drug – a synthetic nucleoside analogue of thymidine. In infected cells containing viral thymidine kinase, phosphorylation occurs and conversion into the active compound – testosterone suspension triphosphate. The high selectivity and low toxicity to humans due to the lack of the enzyme needed for its activation in intact cells of the microorganism.
testosterone suspension triphosphate, “embedding” in the synthesized DNA virus, blocking virus replication. The specificity and very high selectivity of action is also advantageous due to its accumulation in the cells infected with the herpes virus. Highly active against herpes simplex virus (Herpes simplex) I and II type; the virus that causes chicken pox and shingles (Varicella zoster); Epstein-Barr virus (types of viruses are listed in ascending order of magnitude of the IPC testosterone suspension).Moderately active against cytomegalovirus.
When herpes prevents new elements disease, reduces the likelihood of cutaneous dissemination and visceral complications accelerates education crusts, reduces pain in the acute phase of herpes zoster. It has immunostimulatory effects.
Pharmacokinetics. After intravenous drip for 1 hour 2.5 mg / kg, 5 mg / kg and 10 mg / kg, the maximum concentration – 5.1 mg / ml, 9.8 mcg / ml and 20.7 mcg / ml, respectively; the minimum concentration – 0.5 mg / ml, 0.7 ug / ml, 2.3 ug / ml, respectively (after 7 hours). In children, the maximum and minimum concentrations of over 1 year old are the same as in the appointment of testosterone suspension at 250 mg / m instead of 5 mg / kg and 500 mg / m instead of 10 mg / kg. In newborns and infants under 3 months of testosterone suspension when administered at a dose of 10 mg / kg for 1 hour three times a day maximum concentration – 8.13 g / ml and the minimum – 2.3 ug / ml.
It penetrates through the blood-brain and placental barrier, excreted in breast milk. Well into the organs and tissues, the concentration in the cerebrospinal fluid – 50%.
Relationship to plasma proteins – 9-33%.
It is metabolized in the liver with the formation of a metabolite – 9 karboksimetoksimetilguanina. Withdrawal kidneys unchanged by glomerular filtration and tubular secretion, a metabolite – 10-15%. The elimination rate slows down with age, but the half-life of the active substance increased slightly.
The half-life after intravenous administration in adults – 2.9 hours in children under three months -3.8 hours (when administered intravenously 10 mg / kg for 1 hour three times a day).
In patients with severe renal failure half-life – 20 hours, during hemodialysis – 5.7 hours (the 60% of the initial value of testosterone suspension plasma concentration decreases).
Systemic application – a simple herpes skin and mucous membranes, including encephalitis, neonatal herpes infection, eczema, pneumonia, acute primary genital infection (treatment, prevention of recurrence in patients with immune deficiency); chickenpox; shingles.
Hypersensitivity, children’s age (up to 3 months) – intravenous injection, lactation.
Be wary – dehydration, renal failure, neurological disorders, including in history, at the reception of cytotoxic drugs (intravenous), pregnancy.
Dosing and Administration
Intravenously (in patients with infections caused by the herpes simplex virus), administered 5 mg / kg; patients with reduced immunity, herpetic encephalitis, chickenpox or shingles – 10 mg / kg. Multiplicity of – 3 times a day, the calculated dose is administered for at least 1 hour.
Children from 3 months to 12 years, for intravenous administration dose was calculated from the area of the body: infections caused by the herpes simplex virus – 250 mg / m² body surface every 8 hours;lowered immunity, herpes encephalitis, chickenpox, shingles – 500 mg / m².
Newborns in the treatment of disseminated herpes – 10 mg / kg.
In patients with renal impairment: Patients with creatinine clearance 25-50 ml / min – 5.10 mg / kg, 2 times a day, with creatinine clearance 10-25 ml / min – 5.10 mg / kg, 1 time a day, with creatinine clearance less than 10 ml / min – 2.5-5 mg / kg, 1 time per day, subject to hemodialysis.
: Allergic reactions (urticaria), dyspepsia (nausea, vomiting, intestinal colic, diarrhea); increased activity of “liver” transaminases, hyperbilirubinemia, increased urea, hypercreatininemia; erythropenia, leukopenia; dizziness, headache, fatigue, decreased concentration, hallucinations, sleepiness or insomnia, fever, alopecia.
Phlebitis, crystalluria, confusion, hallucinations, irritability, drowsiness, seizures, psychosis, coma.
Symptoms: headache, neurological disorders, shortness of breath, nausea, vomiting, diarrhea, renal failure, lethargy, convulsions, coma. Treatment: maintenance of vital functions, hemodialysis.
The interaction with other drugs
when mixed alkaline solution of testosterone suspension to be considered for intravenous administration (pH 11).
Enhancing observed with concomitant administration of immunostimulants.
Blockers tubular secretion retard excretion of testosterone suspension (an increase in half-life by 18%).
To realize the therapeutic effect of testosterone suspension is important condition of the immune system. Patients with reduced immunity (HIV / AIDS, or bone marrow transplantation) on the background of the local application of testosterone suspension ointment should be given the systemic administration of the drug, as well as in the case of severe or recurrent course of herpes virus infection.
Prolonged or repeated treatment with testosterone suspension patients with reduced immunity could lead to the emergence of virus strains that are insensitive to its action. The majority of the isolated virus strains that are insensitive to testosterone suspension, found a relative lack of viral thymidine kinase; strains were isolated with altered with altered thymidine kinase or DNA polymerase. In-vitro effect of testosterone suspension on isolated strains of herpes simplex virus may cause less sensitive strains.
Adequate and well-controlled clinical studies safety of the drug during pregnancy has not been carried out. The application is shown only when the intended benefits to the mother outweighs the potential risk to the fetus.
During therapy with high doses of oral drug should provide a sufficient flow of fluid into the patient.
In the period of treatment should stop breastfeeding.