Acyclovir is a synthetic purine analogue acyclic nucleoside analogue. Acyclovir is converted to its triphosphate form, acyclovir triphosphate acvtp, which competitively inhibits viral dna polymerase. Antiviral agents knowledge for medical students and. Valacyclovir is converted to acyclovir, which is converted to its triphosphate form, acyclovir triphosphate acvtp. The discovery that acyclovir acycloguo, 92hydroxyefhoxymethylguanine was a potent inhibitor of the replication of herpes simplex virus types 1 and 2 hsv1, hsv2 with very low toxicity for the host cells 1,2 led to an extensive investigation of its mechanism of action and selec tivity. Acyclovir is widely used in the treatment of herpesvirus infections. Acyclovir is selectively acted upon by the viral thymidine kinase. Normal dosage 200 mg q4hr or 400 mg q12hr and crcl acyclovir class. After conversion in vivo to the active metabolite acyclovir triphosphate by viral thymidine kinase, acyclovir competitively inhibits viral dna polymerase by incorporating into. The mechanism of action, pharmacokinetics and toxicity of acyclovir. Acyclovir is a poor substrate for host cellspecified thymidine kinase. The chemical name of acyclovir is 2amino1,9dihydro92hydroxyethoxymethyl6 hpurin6one. Sep 12, 2019 on this episode acyclovir pharmacology i discuss the mechanism of action, important monitoring parameters, and drug interactions with acyclovir.
Acyclovir triphosphate inhibits viral dnapolymerase terminating the chain and is the active form. Valacyclovir is the hydrochloride salt of the lvalyl ester of the antiviral drug acyclovir. Its monophosphate form also incorporates into the viral dna, resulting in chain termination. Antivirals and mechanism of action antiviral drug virus. The inhibitory activity of acyclovir is highly selective due to its affinity for the enzyme thymidine kinase tk encoded by hsv. The action is related to the affinity for the enzyme thymidine kinase tk. Acyclovir mechanism of action 3d medical animation youtube. Aciclogtp competitively inhibits and inactivates the viral dna polymerase. Acyclovir is a synthetic purine nucleoside analogue with inhibitory activity against herpes simplex virus types 1 hsv1, 2 hsv2, and varicellazoster virus vzv. The phosphorylated drug is incorporated into the replicating viral dna strand and inhibits the viral dna polymerase termination of viral dna synthesis. On this episode acyclovir pharmacology i discuss the mechanism of action, important monitoring parameters, and drug interactions with acyclovir. Mechanism of action and selectivity of acyclovir sciencedirect.
Acyclovir is used to treat infections caused by herpes viruses, such as genital herpes, cold sores, shingles, and chicken pox, as well as varicella chickenpox, and. A180730 acyclovir is becomes acyclovir monophosphate due to the action of viral thymidine kinase. Zovirax fda prescribing information, side effects and uses. Acyclovir zovirax is a prescription drug used to treat herpes infections including shingles. Apr 15, 2018 acyclovir is an antiviral drug used mainly for herpes zoster infection.
Learn about side effects, drug interactions, dosages, warnings, and more. Acyclogtp persists in hsvinfected cells for many hours after acyclovir is removed from the medium. Acyclovir, 92hydroxyethoxymethylguanine, is an acyclic nucleoside analogue which has a high activity and selectivity for herpes viruses, particularly herpes simplex viruses types 1 and 2 and varicella zoster virus. Acyclovir, 92hydroxyethoxymethylguanine, is an acyclic nucleoside analogue which has a high activity and selectivity for herpes viruses, particularly herpes simplex viruses types 1. Acyclovir is converted to its triphosphate form, acyclovir triphosphate acvtp, which competitively inhibits viral dna polymerase, incorporates into and terminates the. Aciclogtp, the active triphosphate metabolite of aciclovir, is a very potent inhibitor of viral dna replication. Acyclovir is an acyclic analogue of 2deoxyguanosine.
It slows the growth and spread of the herpes virus in the body. Acyclovir inhibits viral dna synthesis and must be phosphorylated intracellularly to be active. Acyclovir monophosphate is subsequently converted to a triphosphate which is a more potent inhibitor of herpes virus dna polymerases than of cellular dna. Pdf the effects and pharmacokinetics of acyclovir in. Jan 22, 2020 virology mechanism of antiviral action.
Acyclovir is used to decrease pain and speed the healing of sores or blisters in people who have. Aciclovir acv, also known as acyclovir, is an antiviral medication. It is primarily used for the treatment of herpes simplex virus infections, chickenpox, and shingles. Management of acyclovir resistant herpes simplex and varicellazoster infections. Acyclovir is a new antiviral drug that acts as a specific inhibitor of herpesvirus dna polymerase. Scientist emeritus, wellcome research laboratories, 3030 cornwallis road, research triangle park, nc 27709search for more papers by this author. Drugs az pill identifier supplements symptom checker diseases dictionary media.
Antivirals and mechanism of action free download as powerpoint presentation. Acyclovir is widely used in the treatment of herpesvirus infections, particularly herpes simplex virus hsv and varicellazoster virus vzv. The amounts of acyclogtp formed in hsvinfected cells are 40 to 100 times greater than in uninfected vero cells. It shows good in vitro activity against herpes simplex and varicellazoster viruses. Valacyclovir hydrochloride is rapidly converted to acyclovir which has demonstrated antiviral activity against herpes simplex virus types 1 hsv1 and 2 hsv2 and varicellazoster virus vzv both in vitro and in vivo. Orally administered, valacyclovir is rapidly converted to acyclovir which inhibits viral dna replication after further conversion to the nucleotide analog acyclovir triphosphate by viral thymidine kinase, cellular guanyl cyclase, and a number of other cellular enzymes. Acyclovir is converted to the monophosphate by viral. Acyclovir is a synthetic purine nucleoside analogue with cell culture and in vivo inhibitory activity against hsv types 1 hsv1 and 2 hsv2. Zovirax acyclovir, a synthetic acyclic purine nucleoside analog, is a substrate with a high degree of specificity for herpes simplex and varicellazoster specified thymidine kinase. Other uses include prevention of cytomegalovirus infections following transplant and severe complications of epsteinbarr virus infection. As an established treatment of herpes simplex infection, intravenous, oral and to a lesser extent topical formulations of acyclovir provide significant therapeutic benefit in genital herpes simplex and recurrent orofacial herpes simplex. The acyclovir monophosphate acyclogmp is subsequently converted to acyclovir triphosphate acyclogtp by cellular enzymes.
Acyclovir is an antiviral drug used mainly for herpes zoster infection. The drug may be administered topically to the skin, intravenously, orally, or topically to the eye only topical and intravenous preparations are currently. Acyclovir is approved by the food and drug administration as a prescription drug that is commonly used as a topical, injectable, and oral treatment for genital herpes and cold sores. Do not administer acyclovir injectable topically, im, subcut, po, or in the eye. Acyclovir is an antiviral drug, a synthetic nucleoside analogue, that has inhibitory activity interferes with viral replication against the herpes viruses, including herpes simplex 1 and 2 cold sores and genital herpes, varicella zoster shingles and chickenpox, and. Acyclovir is a synthetic analog of the purine nucleoside, guanosine, with potent antiviral activity against herpes simplex viruses type 1 and 2, varicellazoster virus and other viruses of the herpesvirus family. The inhibitory activity of acyclovir is highly selective due to its affinity for the enzyme. It shows good in vitro activity against herpes simplex and varicella. A180757 acyclovir monophosphate is converted to the diphosphate form. Acyclovir acyclovir sodium dose, indications, adverse. Herpes refers to a group of viruses that cause a variety of herpes infections including genital herpes, shingles, chicken pox also chickenpox, cold sores, and encephalitis inflammation of. Pdf the effects and pharmacokinetics of acyclovir in neonates. Ribavirin, also known as tribavirin, is an antiviral medication used to treat rsv infection, hepatitis c and some viral hemorrhagic fevers.
Antiviral agents knowledge for medical students and physicians. The discovery of acyclovir zovirax was first reported in i977. It is 30 times more potent against the herpes simplex virus enzyme than the host enzyme. Acyclovir aciclovir is a nucleoside antiviral drug with antiviral activity in vitro against members of the herpes group of dna viruses. Acyclovir is a white, crystalline powder with the molecular formula c 8 h 11 n 5 o 3 and a molecular weight of 225. Acyclovir is an effective antiviral medication used primarily for treating the symptoms of herpes simplex virus infections, chickenpox, and shingles. Acyclovir is a synthetic purine nucleoside analogue with in vitro and in vivo inhibitory activity against herpes simplex virus types 1 hsv1, 2 hsv2, and varicellazoster virus vzv.
Acyclovir is an antiviral drug, a synthetic nucleoside analogue, that has inhibitory activity interferes with viral replication against the herpes viruses, including herpes simplex 1 and 2 cold sores and genital herpes, varicellazoster shingles and chickenpox, and epsteinbarr virus mononucleosis. What is acyclovir, and how does it work mechanism of action. Acyclovir i development represents a watershed in the field of antiviral chemotherapy acyclic guanosine analog active vs. Acyclovir or aciclovir is a humanmade purine nucleoside analog which suppresses the activity of all two types of herpes simplex virus hsv1 and 2, and varicellazoster. For hepatitis c, it is used in combination with other medications such as simeprevir, sofosbuvir, peginterferon alfa2b or peginterferon alfa2a. Zovirax acyclovir dosing, indications, interactions. It shows good in vitro activity against herpes simplex and. An overview of the mechanisms of action of and resistance to acyclovir and its major. The enzyme phosphorylates acyclovir to a monophosphate. However, resistance among some virus forms is possible because of changes in tk or in the dna. Oct 23, 2012 acyclovir aciclovir is a nucleoside antiviral drug with antiviral activity in vitro against members of the herpes group of dna viruses. Wellcome research laboratories, research triangle park, north carolina. Action and clinical pharmacology mechanism of action. It will not cure herpes, but it can lessen the symptoms of the infection.
Acyclovir, an acyclic purine nucleoside analog, is a highly potent inhibitor of herpes simplex virus hsv, types 1 and 2, and varicella zoster virus, and has. May 06, 2017 acyclovir purine analogue mechanism of action aciclovir is converted by viral thymidine kinase to aciclovir monophosphate, which is then converted by host cell kinases to aciclovir triphosphate acv tp. Hsv, vzv and modestly cmv mechanism of action preferentially taken up by virally infected cells monophosphorylated by virally encoded thymidine kinases di and triphosphorylation completed by. Acyclovir purine analogue mechanism of action aciclovir is converted by viral thymidine kinase to aciclovir monophosphate, which is then converted by host cell kinases to aciclovir triphosphate acv tp. The biochemistry and mechanism of action of acyclovir. An overview of the mechanisms of action of and resistance to acyclovir and its major clinical uses will be provided here. Dosing and treatment of the specific clinical syndromes are described in greater. Reconstitute 500mg or 1g vial with 10 ml or 20 ml, respectively, of sterile water for injection. Hsv, vzv and modestly cmv mechanism of action preferentially taken up by virally infected cells monophosphorylated by virally encoded thymidine kinases di and triphosphorylation completed by cellular kinases acvtp is the active moiety. Acyclovir monophosphate is subsequently converted to a triphosphate which is a more potent inhibitor of herpes virus dna polymerases than of cellular dna polymerases. Acyclovir is a synthetic purine nucleoside analogue with in vitro and in vivo inhibitory activity against herpes simplex virus types 1. Selective action in infected cells only minimal effect on host cells dna replication. Viruses take over living cells and reproduce themselves, often at the expense.
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