Pharmacology of Ganciclovir, Valganciclovir and Aciclovir
-
Upload
aniah-azmi -
Category
Health & Medicine
-
view
66 -
download
3
description
Transcript of Pharmacology of Ganciclovir, Valganciclovir and Aciclovir
![Page 1: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/1.jpg)
Pharmacology
Aciclovir, Valganciclovir & GanciclovirBy Noor Aniah Azmi (MBBCh Cairo, Egypt)
Medical retina
team
presentation
![Page 2: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/2.jpg)
Objectives
oUnderstand about each of the antiviral
oUnderstand the indications for their use
o Learn about the virus life cycle
![Page 3: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/3.jpg)
Now, let’s learn about the
virus life cycle
![Page 4: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/4.jpg)
![Page 5: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/5.jpg)
Ganciclovir
Synthetic guanosine analogue
First antiviral approved for CMV treatment
![Page 6: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/6.jpg)
How does it work?
![Page 7: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/7.jpg)
How come it doesn’t work in some cases?
Mutations UL97 – encodes of CMV phospotransferase
.
![Page 8: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/8.jpg)
Which virus does it attack?
![Page 9: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/9.jpg)
In what preparations do they exist?
Zirgan ointment 0.15% - ophthalmic gel Cytovene 500 mg
![Page 10: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/10.jpg)
What are the effects of the body on the drug?
Absorption: • Oral – very limited• t ½ : 2-6 hours
Distribution: All tissues• Especially CSF and ocular tissue
Excretion: 80-90% unchanged in urine
![Page 11: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/11.jpg)
When do we use Ganciclovir?
1. Herpes Epithelial Keratitis Ganciclovir Gel 0.15% (Zirgan)
2. CMV Retinitis
Initial: IV 5mg/kg BD for 14-21 daysMaintenance: IV 5mg/kg OD or IV 6 mg/kg OD for 5 days/week
![Page 12: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/12.jpg)
What are the side effects?
Bone marrow supression Neutropenia Granulocytopenia
TOXICITY Potential carcinogen Teratogen Inhibits spermatogenesis
![Page 13: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/13.jpg)
ValganciclovirProdrug of Ganciclovir
Taken orally
Changed to Ganciclovir by intestinal/hepatic esterase
![Page 14: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/14.jpg)
In what preparations do they exist?
Valcyte Tablet 450 mg Valcyte Oral Solution 50 mg/mL
![Page 15: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/15.jpg)
What are the effects of the body on the drug?
Absorption: • Well-absorbed especially with fatty meals
Distribution: • Well distributed especially CSF and ocular tissues
Metabolism: • In liver & intestine changed to Ganciclovir
Excretion: 80-90% in urine
![Page 16: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/16.jpg)
When do we use Valganciclovir?
CMV Retinitis
Initial: Oral 900 mg BD x 21 daysMaintenance: Oral 900 mg OD
![Page 17: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/17.jpg)
AciclovirMost commonly used antiviral
Commonly used for HSV and Chickenpox
![Page 18: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/18.jpg)
How does it work?
![Page 19: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/19.jpg)
How come it doesn’t work in some cases?
• Deficient viral thymidine-kinase
• Mutations to viral thymidine-kinase or DNA polymerase
.
![Page 20: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/20.jpg)
Which virus does it attack?
Herpes-simplex 1 Herpes-simplex 2 Varicella-zoster virus Epstein-Barr virus Cytomegalovirus
Most activity
![Page 21: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/21.jpg)
In what preparations do they exist?
Zovirax ointment 3% Tablet Aciclovir 200 mg / 400 mg
![Page 22: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/22.jpg)
What are the effects of the body on the drug?
Absorption: • Poor water-soluble• Poor oral bioavailability
Distribution: High distribution rate• T ½: 3 hours
Metabolism: Small amounts – liver
Excretion: 62-90% unchanged in urine
![Page 23: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/23.jpg)
![Page 24: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/24.jpg)
When do we use Aciclovir?
Herpes-Zoster Ophthalmicus Herpex Simplex Blepharitis
Herpes keratitis
![Page 25: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/25.jpg)
What are the side effects?
Systemic Nausea, vomiting Encephalopathy IV
Local SPK Allergy
![Page 26: Pharmacology of Ganciclovir, Valganciclovir and Aciclovir](https://reader037.fdocuments.net/reader037/viewer/2022110114/5470651caf795924258b4587/html5/thumbnails/26.jpg)