· Medication for first episode ofGenital Herpes:The number of antiviral medications against thefirst episode of Genital Herpes are many. Genital Herpes is usuallycharacterized as HSV – 1 and HSV – 2. It is understood that all othermedications are nucleoside analogues except foscarnet and cidofovir. The majorthree medications namely acyclovir, famciclovir and valaciclovir are consideredas effective medications against HSV – 1 and HSV – 2. Other antiviruses mentionedabove, such as cidofovir, foscarnet, ganciclovir and valganiciclovir have alsohelped greatly in combating the first episodes of genital herpes. These arealso useful against alpha herpes virus.
They are used in special conditionssuch as treatment of some acyclovir – resistant HSV isolates. Acyclovir:It is a prototypic antiviral agent. Itactivates viral induced enzyme thymidine kinase in the initial stages of thefirst episode. The activity of acyclovir against VZV is ten times less thanit’s activity against HSV. On the other hand, Epstein Barr Virus has minimal thymidinekinase activity because of it’s moderate susceptibility towards acyclovir.
MechanismOf Action: Acyclovir is known to be a deoxyguanosineanalogue. It has an acyclic side chain that lacks a 3 – hydroxyl group from thegroup of natural nucleotides. Since the missing group is required for thegrowth of DNA, the growth gets terminated. Hence, the viral DNA polymerase getsinactivated. This is where acyclovir comes into action.
It is much moreeffective and a better substrate to for the viral polymerase instead ofcellular DNA polymerase. The end result is the incorporation of acyclovir intocellular DNA. · Medication for recurrentepisode of Genital Herpes:An effective treatment for reoccurringepisodes of Genital herpes is intravenous acyclovir therapy. The treatment isused when the patient encounters severe episodes of HSV or is hospitalized dueto an escalated situation. A total of 5 – 10 mg/kg IV every eight hours forabout 2-7 days is the recommended regiment. This may it may not be continuedbeyond 7 days which depends upon the clinical observation.
Then follows an oralantiviral therapy which is to be undertaken for at least 10 days after thetotal therapy. HSV encephalitis is an intravenous therapy that requires aminimum of 21 days. Adjustment in the acyclovir dosage is confirmed with animpaired renal function. Like every other medication that issynthesized, acyclovir has it’s own set of allergies and adverse reactions thatare different in different individuals. They are not completely absent, theallergies and side effects are rare.
Researchers have also found desensitizationof acyclovir.