Active Ingredients

Ganciclovir – Effect, Application & Risks


An antiviral drug is called ganciclovir . It is effective against herpes viruses .

What is ganciclovir?

Ganciclovir is an analogue of the nucleobase guanine. As an antiviral, it is used to treat infections caused by herpes viruses. The active ingredient was approved in Europe in the 1980s.

In Germany, the drug is used under the product names Virgan® and Cymeven®. There is a structural relationship between the antivirals ganciclovir, penciclovir and aciclovir .

Pharmacological action

As an antiviral, ganciclovir has the property of inhibiting the growth of viruses . The drug primarily acts against herpes viruses, which include the entire human herpes virus family . Its effects against the cytomegalovirus (CMV) are particularly pronounced . For this reason, medicine usually uses it against this germ .

After the ganciclovir enters the patient’s body, a chemical transformation occurs there. The result is the effective form of the antiviral, which is ganciclovir triphosphate. This substance is mainly formed in the body cells that are infected by viruses. The drug is phosphorylated by different kinases, which serves for subsequent incorporation into the DNA of the virus.

Ganciclovir is very similar to the viral DNA building block guanine. This misincorporation results in a chain break, since ganciclovir, as a viral polymerase, is not recognized as a building block. There is therefore no further replication of the viral DNA. So the virus can no longer multiply.

However, one of the disadvantages of ganciclovir is that its effects are not targeted. The antiviral not only inhibits the growth of viruses, but also has a negative effect on the metabolic processes of healthy body cells. The consequences of this are sometimes some serious side effects .

Oral bioavailability of ganciclovir is low at just 5 percent. For this reason, it is often given intravenously. The antiviral is excreted almost unchanged from the body via the kidneys . If renal function is normal, the elimination half-life is between 1.5 and 3 hours.

Medical Application & Use

The main areas of application for ganciclovir are diseases caused by the human herpes virus 5 (HHV 5). It is also known as cytomegalovirus. As a rule, the indications are an immune deficiency (such as in AIDS ) and organ transplants .

As an eye gel, ganciclovir is also suitable for the treatment of eye herpes (keratitis herpetica). Furthermore, experimental treatments of malignant degenerations, for which oncolytic viruses are responsible, take place. Ganciclovir is also used in biochemistry for negative selection.

Due to the low oral bioavailability of the antiviral, the patient is normally given two single doses of 5 milligrams per kilogram of body weight every day. The administration takes place as an infusion at time intervals of 12 hours. The infusion is given through a large vein .

However, ganciclovir can also be administered orally. In this case, the patient takes 1 gram per day between meals. External dosage forms in the form of eye gels have also been available in Germany since 2006.

Risks & side effects

Since ganciclovir has significantly higher toxic properties than other antivirals such as aciclovir, there is a greater risk of side effects, which can be very diverse. This often leads to a reduction in certain white blood cells , diarrhea , breathing difficulties , a lack of white blood cells , loss of appetite , fungal infections in the mouth, headaches , sleeping problems , urinary tract infections , cellulite , anxiety disorders , depression , confusion ,abdominal pain , nausea , vomiting , cough , difficulty swallowing and constipation .

Other unwanted side effects are thought disorders , anorexia , skin inflammation , itching , night sweats , earache , nerve disorders, liver dysfunction , muscle pain , back pain , fever , fatigue , rigidity, chest pain , weakness and weight loss .

Even detachment of the retina and blood poisoning (sepsis) are possible. Cardiac arrhythmias , hearing loss , visual disturbances , severe allergic reactions , heartburn , hair loss , infertility in men , kidney failure and psychoses also occasionally occur .

If the patient suffers from an allergy or hypersensitivity to ganciclovir or other antivirals such as valaciclovir , valganciclovir and aciclovir, the drug must never be administered to him. This also applies if there is a pronounced lack of platelets or white blood cells or if the hemoglobin value is too low .

Careful dosing by the doctor is required in the case of renal dysfunction. In such cases, the physician must weigh the risks and benefits against each other.

During pregnancy and breastfeeding , ganciclovir must not be used under any circumstances, as the child could otherwise suffer serious damage or malformations. Consistent contraception is recommended when taking the drug . Ganciclovir is also not suitable for children under the age of 18.

Taking ganciclovir at the same time as certain other medicines can cause interactions. There is often a risk of an increased disruption in blood cell formation . The risk is particularly high for drugs used to treat cancer. These include cytostatics such as vinblastine and vincristine , and chemotherapeutic agents such as pentamidine and dapsone . There is also a danger with antifungal agents such as flucytosine and amphotericin B .

It is not recommended to give ganciclovir with the active substance zidovudine , which is also used to fight viruses. In the case of a combination, the patient is threatened with severe damage to blood cell formation. If ganciclovir is given concomitantly with cephalosporins or penicillins , there is a risk of seizures .

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.