Treating Infection Caused by Herpes Virus (Genital and Cold Sores)
Valacyclovir is a generic drug available in market with brand names Valtrex and Zelitrex.
- It is an antiviral drug.
- It helps to treat Herpes simplex, herpes zoster (shingles), and herpes B.
- It is helpful in treating infection caused by herpes virus including genital herpes and cold sores.
HISTORY:
Burroughs welcome Co. (at present GSK) developed several water soluble ester of acyclovir. One of them was the above described drug. They patented the invention of this drug in 1988.It is at present marketed by Glaxo Smith Kline (GSK). They sold it under brand names Valtrex and Zelitrex. It is available as generic drug in US since November 25, 2009. It was first discovered in 1988 in USA
Herpes zoster (shingles) – June 1995
Recurrent genital herpes – December 1995
Initial infection of genital herpes – October 1996
Suppressive therapy for genital herpes – September 1997
Cold sores (Herpes labialis) – September 2002
MECHANISM OF ACTION:
Valacyclovir is a prodrug. That means it isn’t active itself. It converts into acyclovir in the body. It is active against viruses. It help to avoid the replication of viral DNA. This is necessary for viral DNA to multiply. This stops the spread of virus in the body. So the above drug is active against the same viruses as acyclovir. But it show advantages due to longer duration of action. Due to this advantage the number of pill per day reduces.
DOSAGES:
Valacyclovir is available in 500 and 1000 mg tablet. It is an oral medicine. Take it with or without food. Drinking plenty of water reduce the chances and the strength of side effects. Dosage is dependent on the type of infection and medical condition. For chicken pox in children amount of drug is as per weight of child. For shingles it is necessary to start medicine as the rashes appear. Keep the amount medicine at a constant level to see best effects. Avoid changing, skipping or stopping your dose till the course complete. This will ensure the effect of the drug.
ADVANTAGES:
- It treats infection caused by certain types of virus.
- In children, it treats cold sores near the mouth caused by herpes simplex
- It help to cure chickenpox caused by zoster
- In adults it treats shingles and cold sores near the mouth
- Helps to treat outbreak of genital herpes
- It reduces the number of future out breaks
- It decreases the severity out break
- It helps to heal the sores
- Decreases the pain and itching
SIDE EFFECTS:
Some of the common side effects observe are as follows;
- Vomiting
- Nausea
- Headache
- Increased liver enzymes
- Abdominal pain
- Cold symptoms
Above symptoms are temporary. They appear for short period. They disappear as body become used to the medicine. Other serious side effects are as discussed below;
- Central nerves problems
- Agitation
- Increased heart rate
- Confusion
- Depression
- Some brain disorder
These are rare cases. But it is important to take doctor advice.
PRECAUTIONS:
- Reduced dosage for kidney patients
- No adequate evidence present to show its safety in pregnant or breast feeding women. Use it if benefit to the mother outweighs risk to the fetus
- Safety and efficiency isn’t proved in patients
< 12 years of age with cold sores
< 2 years of age or > than 18 years of age with chickenpox
< 18 years of age with genital herpes
< 18 years of age with herpes zoster
- Counseling for safe sex practices
- Adequate hydration
COST OF VALACYCLOVIR VERSUS BRAND VELTREX:
The generic version is cheaper than brand ones. They show same effect as brand version. They vary in case of cost. The cost of generic version is low i.e.; $ 0.91 for per pill of 500 mg tablet and $ 1.22 for per pill of 1000 mg tablet. The brand Valtrex by canDrugstore.com is as high as $ 5.40 for per pill of 500 mg tablet. Online drugs sells 1000 mg per pill for $9.92.