Subsequently, cellular kinases catalyze the formation of ganciclovir diphosphate and ganciclovir triphosphate, which is present in 10-fold greater concentrations in CMV or herpes simplex virus (HSV)-infected cells than uninfected cells. Ganciclovir triphosphate is a competitive inhibitor of deoxyguanosine triphosphate (dGTP) incorporation into DNA and preferentially inhibits viral DNA polymerases more than cellular DNA polymerases. In addition, ganciclovir triphosphate serves as a poor substrate for chain elongation, thereby disrupting viral DNA synthesis by a second route. Pharmacokinetics
Absorption of the oral form is very limited—about 5% fasting, about 8% with food. It achieves a concentration in the central nervous system of about 50% of the plasma level. About 90% of plasma ganciclovir is eliminated unchanged in the urine, with a half-life of 2–6 hours, depending on renal function (elimination takes over 24 hours in end-stage renal disease). Administration
Acute infections are treated in two phases: 

induction phase, 5 mg per kilogram intravenously every 12 hours for 14–21 days, the intravenous dose given as a 1-hour infusion
maintenance phase, 5 mg per kg intravenously every dayStable disease is treated with 1000 mg orally three times daily. Similar dosing is used to prevent disease in high-risk patients, such as those infected with human immunodeficiency virus (HIV) or those with organ transplants. Ganciclovir is also available in slow-release formulations for insertion into the vitreous humour of the eye, as treatment for CMV retinitis (associated with HIV infection). A topical ophthalmic gel preparation of ganciclovir was recently approved for the treatment of acute herpes simplex keratitis. See also
Valganciclovir, the prodrug of ganciclovir

References
Further reading
External links
"Ganciclovir".
Chills is a feeling of coldness occurring during a high fever, but sometimes is also a common symptom which occurs alone in specific people. It occurs during fever due to the release of cytokines and prostaglandins as part of the inflammatory response, which increases the set point for body temperature in the hypothalamus. The increased set point causes the body temperature to rise (pyrexia), but also makes the patient feel cold or chills until the new set point is reached. Shivering also occurs along with chills because the patients body produces heat during muscle contraction in a physiological attempt to increase body temperature to the new set point. When it does not accompany a high fever, it is normally a light chill. Sometimes a chill of medium power and short duration may occur during a scare, especially in scares of fear, commonly interpreted like or confused by trembling. Severe chills with violent shivering are called rigors. Causes
Chills are commonly caused by inflammatory diseases, such as influenza. It is also common in urinary tract infections. Malaria is one of the common reasons for chills and rigors. In malaria, the parasites enter the liver, grow there and then attack the red blood cells which causes rupture of these cells and release of a toxic substance hemozoin which causes chills recurring every 3 to 4 days. Sometimes they happen in specific people almost all the time, in a slight power, or it less commonly happens in a generally healthy person. See also
Cold chill
Goose bumps
Night sweats

References


== External links ==