Ganciclovir (INN) (IPA: ) is an antiviral medication used to treat or prevent cytomegalovirus (CMV) infections. It was developed by Canadian scientist Kelvin K. Ogilvie.[Ogilvie KK. Biography – Kelvin K. Ogilvie Wolfville (NS): Acadia University; c2003. [updated 2003 Sep 17; cited 2006 May 28. Available from: http://ace.acadiau.ca/science/chem/faculty/kko/Biography.html] Ganciclovir sodium is marketed under the trade names Cytovene and Cymevene (Roche). Ganciclovir for ocular use is marketed under the trade name Vitrasert (Bausch & Lomb). A prodrug form with improved oral bioavailability (valganciclovir) has also been developed.
Mechanism of action
Ganciclovir is a synthetic analogue of 2'-deoxy-
guanosine. It is first
phosphorylated to a deoxyguanosine triphosphate (d
GTP) analog. This competitively inhibits the incorporation of dGTP by viral
DNA polymerase, resulting in the termination of elongation of viral
DNA.
Clinical use
Indications
Ganciclovir is indicated for:
[Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006. ISBN 0-9757919-2-3]
It is also used for acute CMV colitis in HIV/AIDS and CMV pneumonitis in immunosuppressed patients.
Adverse effects
Ganciclovir is commonly associated with a range of serious
haematological adverse effects. Common
adverse drug reactions (≥1% of patients) include:
granulocytopenia,
neutropenia,
anaemia,
thrombocytopenia, fever, nausea, vomiting,
dyspepsia, diarrhoea, abdominal pain, flatulence, anorexia, raised liver enzymes, headache, confusion, hallucination, seizures, pain and
phlebitis at injection site (due to high pH), sweating, rash, itch, increased serum
creatinine and blood
urea concentrations.
Toxicity
Ganciclovir is considered a potential human
carcinogen,
teratogen, and
mutagen. It has also considered likely to cause inhibition of
spermatogenesis. Thus, it is used judiciously and handled as a
cytotoxic drug in the clinical setting
[Roche Products Pty Ltd. Cymevene (Australian Approved Product Information). Dee Why (NSW): Roche; 2005.]
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 hrs, 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 day
Stable 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).
References
Further reading
- Noble S, Faulds D. Ganciclovir. An update of its use in the prevention of cytomegalovirus infection and disease in transplant recipients. Drugs. 1998;56(1):115-46
- Spector SA. Oral ganciclovir. Adv Exp Med Biol. 1999;458:121-7
- Couchoud C. Cytomegalovirus prophylaxis with antiviral agents for solid organ transplantation. Cochrane Database Syst Rev. 2000;(2):CD001320.
Antivirals
ガンシクロビル | แกนซิโคลเวียร์