Drug Interaction:
Interacting drugs- summary
Valcyclovir +
Cimetidine/Probenecid
admin of these agents separately or together, reduced the rate, but not the extent, of conversion of valcyclovir to acyclovir. The renal clearance of acyclovir reduced.
Indication:
Approved by FDA on June 23,1995
New Drugs Approved by (DCI) Drug Controller GENERAL - India For Marketing
(Ref- IDMA Publication)
Name of Drug Indication Date of Approval
Valacyclovir Anti-Viral 25-09-2002
Herpes zoster
Adverse Reaction:
Nausea, headache, Vomiting, diarrhea, Constipation, asthenia, Dizziness, abdominal pain, Anorexia.
Contra-Indications:
Hypersens to the drug
Special precautions:
Renal function impairment, elderly, pregnancy, lactation
Dosages/ Overdosage Etc:
Approved by FDA on June 23,1995
Indications:
Herpes zoster
Dosage:
Recommended dose is 500mg twice daily for 7 days Initiate therapy at the earliest symptom of Herpes zoster
Other Information:
EVIDENCE- BASED MEDICINE (April 2003)
Genital Herpes
Comparative effectiveness of various interventions
Beneficial
1. Oral antiviral therapy in first episodes
2. Oral antiviral treatment taken at start of a recurrence
3. Daily oral antiviral treatment in people with high rates of recurrence.
Likely to be beneficial
1. Daily oral antiviral treatment in late pregnancy. In women with a hostory of genital herpes.
Unknown effectivess
1. Psychotherapy to reduce recurrence
2. Interventions to prevent sexual transmision
3. Serological screening and counselling in late pregnancy
Likely to be ineffective or harmful
1. Abdominal delivery in women with genital lesions at terms.
KEY POINTS
1. Clinical trials have found that oral antiviral treatment reduces the duration of symptoms, lesions, and viral shedding in first and recurrent episodes of general herpes, and that daily treatment reduces the rate of recurrence.
2. Trials have found no significant difference in effectivenes or adverse effects beween acyclovir, valacyclovir and famcyclovir.
3. There is insufficient evidence on the role of interventions to prevent sexual transmission.
4. The highest risk of mother-to-baby transmission is in women newly infected with genital herpes in late pregnancy. There is inadquate evaluation of intervention to prevent infection in late pregnancy (such as serological screening and counselling)
5. It has been found that the effect of abdominal delivery on mother-to-baby transmission had not been adequately evaluated. The procedure has the risk of increased maternal morbidity and mortality.
6. Limited evidence from trials suggests that antiviral treatment may reduce the number of pregnant women with genital lesions at term. Since women with genital lesions are usually offered abdominal deliveries, antiviral treatment may reduce the risk of abdomnal delivery
Patient Information:
1. Herpes Zoster- Advise patients to initiate therapy as soon as posible after
diagnosis of Herpes zoster.
2. Recurrent genital herpes- tell patients to avoid contact with lesions and to
avoid intercourse with lesions or symptoms are present to avoid infecting
others. Initiate therapy at the first sign or symptoms of an episode
Ref - USP PDI Vol II 17th Edition (1997)
VALACYLOVIR- SYSTEMIC
1.Allergies-
Tell your doctor if you have ever had any unusual or allergic reaction to
Valacyclovir or acyclovir. Also tell your healthcare care professional if
you are allergic to any other substances such as foods. preservatives
or dyes.
2.Pregnancy-
Adequate and well controlled studies have not been done with valacyclovir
or acyclovir. However, acyclovir has been used in pregnant women and
has not shown to cause birth defects or other problems.
3. Breast-feeding-
It is not known whether valacyclovir passes into breast milk. acyclovir
passes into breast milk and this has not been to cause problems in
nursing babies.
4.Children-
Studies of this medicine has been done only in adult patients. There is
no specific information comparing valacyclovir in children with use in
other age groups.
5.Older adults-
Valacyclovir has been used in elderly and has not been shown to cause
different side effects or problems in older people, than it does in younger
adults.
6. Other medicines-
Tell your doctor if you are using any other prescription or
non-prescription (Over-the counter) OTC medicine.
7. Other medical problems-
The presence of other medical problems may affect the use of valcyclovir.
Make sure you tell your doctor if you have any other medical problems
especially-
Bone marrow transplantation or
Human immunodeficiency virus (HIV) infection, advanced or
Kidney transplatations - patients with these medical problems may
have an increased risks of side effects
Kidney disease- kidney disease may increase blood levels of this medicine,
increasing the chance of side effects.
Pharmacology/ Pharmacokinetics:
Pharmacology:
Valacyclovir is the hydrochloride salt of L-valyl ester of the anti-viral drug acyclovir. Valacyclovir is raidly converted to acyclovir, which has in vitro and in vivo inhibitory activity against herpes simplex
Pharmacokinetics:
After oral admin valacyclovir is rapidly absorbed from the G I tract and is rapidly and nearly converted to acyclovir and L-valine by first pass intestinal or hepatic metabolism.
Pregnancy and lactation:
Pregnancy:
Use Valcyclovir during pregnancy only if needed.
Lactation:
Administer Valacyclovir to nursing mother with caution.