Aciclovir (acyclovir) 200mg 20 tablets — Made in Ukraine — Free Delivery

Acyclovir is a synthetic analogue of a purine nucleoside with in vivo and in vitro inhibitory activity against human herpesvirus, including herpes simplex virus type I and II, chickenpox and herpes zoster virus, Epstein-Barr virus and cytomegalovirus. In cell culture, acyclovir has the greatest activity against herpes simplex virus type I and further, as activity decreases, against herpes simplex virus type II, chickenpox and herpes zoster virus, Epstein-Barr virus and cytomegalovirus.

The inhibitory activity of acyclovir against the above viruses is highly selective. The enzyme thymidine kinase in a normal uninfected cell does not use acyclovir as a substrate, therefore, the toxic effect on the cells of the host organism is minimal. However, thymidine kinase, encoded in herpes simplex viruses, chickenpox viruses, herpes zoster viruses and Epstein-Barr viruses, converts acyclovir into acyclovir monophosphate, a nucleoside analogue, which is then converted sequentially into diphosphate and triphosphate using cell enzymes. Following the insertion of acyclovir into the viral DNA, triphosphate interacts with the viral DNA polymerase, resulting in the termination of the synthesis of the viral DNA chain.

With prolonged or repeated courses of treatment of critically ill patients with reduced immunity, there may be cases of decreased sensitivity of certain strains of the virus, which do not always respond to treatment with acyclovir. Most clinical cases of insensitivity are associated with viral thymidine kinase deficiency, but there are reports of viral thymidine kinase and DNA damage. In vitro interactions of certain herpes simplex viruses with acyclovir can also lead to the formation of less sensitive strains. The relationship between the sensitivity of individual herpes simplex viruses in vitro and the clinical results of treatment with acyclovir is not fully understood.

Acyclovir is only partially absorbed in the intestine. The average peak stable concentration (Cssmax) in blood plasma after taking a dose of 200 mg with a 4-hour interval is 3.1 μmol (0.7 μg / ml), and, accordingly, the level in blood plasma (Cssmin) will be 1.8 μmol (0 , 4 μg / ml). Corresponding Cssmax levels after doses of 400 mg and 800 mg with

The 4-hour intervals are 5.3 μmol (1.2 μg / ml) and 8 μmol (1.8 μg / ml) and the equivalent Cssmin levels were 2.7 μmol (0.6 μg / ml) and 4 μmol (0 , 9 μg / ml).

In adults, the terminal half-life of intravenous acyclovir is approximately 2.9 hours. Most of the preparation is excreted unchanged by the kidneys. The renal clearance of acyclovir is significantly higher than the creatinine clearance, which indicates that the excretion of the preparation by the kidneys is carried out by not only glomerular filtration, but also by tubular secretion.

9-carboxymethoxymethylguanine is the only important metabolite of acyclovir and accounts for approximately 10-15% of the administered dose, which can be determined in urine. If acyclovir is used 1 hour after taking 1 g of probenecid, the terminal half-life and the area under the concentration / time curve increase by 18% and 40%, respectively.

In patients with chronic renal failure, the mean final elimination half-life is 19.5 hours. The average elimination half-life of acyclovir during hemodialysis is 5.7 hours. Plasma acyclovir levels are reduced by about 60% during dialysis.