|Systematic (IUPAC) name|
|Licence data||US FDA:|
|Pregnancy cat.||B3 (AU) B (US)|
|Legal status||Prescription Only (S4) (AU) ℞-only (CA) POM (UK) ℞-only (US)|
|Routes||Intravenous, oral, topical (including eye ointment)|
|Excretion||Renal (62-90% as unchanged drug)|
|ATC code||J05 D06 S01|
|Mol. mass||225.21 g/mol|
|Melt. point||256.5 °C (494 °F)|
|(what is this?)|
Aciclovir (INN, BAN. Brand names: Cyclovir, Herpex, Acivir, Acivirax, Zovirax, Zoral, Xovir and Imavir) // or acyclovir (USAN, former BAN), chemical name acycloguanosine, abbreviated as ACV, is a guanosine analogue antiviral drug. It is one of the most commonly used antiviral drugs, that is primarily used for the treatment of herpes simplex virus infections, as well as in the treatment of varicella zoster (chickenpox) and herpes zoster (shingles).
- Genital herpes simplex (treatment and prevention)
- Herpes simplex labialis (cold sores)
- Acute chickenpox in immunocompromised patients
- Herpes simplex encephalitis
- Acute mucocutaneous HSV infections in immunocompromised patients
- Herpes of the eye
- Herpes simplex blepharitis (a chronic (long-term) form of herpes eye infection)
- Prophylaxis against herpesviruses in immunocompromised patients (such as patients undergoing cancer chemotherapy)
It has been claimed that the evidence for the effectiveness of topically applied cream for recurrent labial outbreaks is weak. An earlier review of scientific literature showed there is some effect in reducing the number and duration of lesions if aciclovir is applied at an early stage of an outbreak. Aciclovir trials show that this agent has no role in preventing HIV transmission, but it can help slow HIV disease progression in people not taking anti-retroviral therapy (ART). This finding emphasizes the importance of testing simple, inexpensive non-ART strategies, such as aciclovir and cotrimoxazole, in people with HIV.
Its use in pregnancy is advised against unless the benefits to the mother outweigh the danger to the foetus. Studies in mice, rabbits and rats (with doses more than 10 times the equivalent of that used in humans) given during organogenesis have failed to demonstrate birth defects. Studies in rats in which they were given the equivalent to 63 times the standard steady-state humans concentrations of the drug[Note 1] on day 10 of gestation showed head and tail anomalies.
Common adverse drug reactions (≥1% of patients) associated with systemic aciclovir therapy (oral or IV) include: nausea, vomiting, diarrhoea, encephalopathy (with IV use only), injection site reactions (with IV use only) and headache. In high doses, hallucinations have been reported. Infrequent adverse effects (0.1–1% of patients) include: agitation, vertigo, confusion, dizziness, oedema, arthralgia, sore throat, constipation, abdominal pain, hair loss, rash and weakness. Rare adverse effects (<0.1% of patients) include: coma, seizures, neutropenia, leukopenia, crystalluria, anorexia, fatigue, hepatitis, Stevens–Johnson syndrome, toxic epidermal necrolysis, thrombotic thrombocytopenic purpura and anaphylaxis.
Intravenous aciclovir may cause reversible nephrotoxicity in up to 5% to 10% of patients because of precipitation of aciclovir crystals in kidney. Aciclovir crystalline nephropathy is more common when aciclovir is given as a rapid infusion and in patients with dehydration and preexisting renal impairment. Adequate hydration, a slower rate of infusion, and dosing based on renal function may reduce this risk.
Aciclovir topical cream is commonly associated (≥1% of patients) with: dry or flaking skin or transient stinging/burning sensations. Infrequent adverse effects include erythema or itch. When applied to the eye, aciclovir is commonly associated (≥1% of patients) with transient mild stinging. Infrequently (0.1–1% of patients), ophthalmic aciclovir is associated with superficial punctate keratitis or allergic reactions.
Detection in biological fluids
Aciclovir may be quantitated in plasma or serum to monitor for drug accumulation in patients with renal dysfunction or to confirm a diagnosis of poisoning in acute overdose victims.
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). ACV-TP, in turn, competitively inhibits and inactivates DNA polymerases and incorporates itself into viral DNA chain.
- Herpes simplex virus type I (HSV-1)
- Herpes simplex virus type II (HSV-2)
- Varicella zoster virus (VZV)
- Epstein-Barr virus (EBV)
- Cytomegalovirus (CMV) – least activity
Resistance to aciclovir is rare, but is more common in patients on chronic antiviral prophylaxis (transplant recipients, people with acquired immunodeficiency syndrome due to HIV infection). Mechanisms of resistance in HSV include deficient viral thymidine kinase; and mutations to viral thymidine kinase or DNA polymerase, altering substrate sensitivity.
Aciclovir is poorly water soluble and has poor oral bioavailability (15–30%), hence intravenous administration is necessary if high concentrations are required. When orally administered, peak plasma concentration occurs after 1–2 hours. Aciclovir has a high distribution rate; protein binding is reported to range from 9 to 33%. The elimination half-life (t1/2) of aciclovir depends according to age group; neonates have a t1/2 of 4 hours, children 1-12 years have a t1/2 of 2-3 hours whereas adults have a t1/2 of 3 hours.
Aciclovir was seen as the start of a new era in antiviral therapy, as it is extremely selective and low in cytotoxicity. Nucleosides isolated from a Caribbean sponge, Cryptotethya crypta, were the basis for the synthesis of aciclovir. It was codiscovered by Howard Schaffer following his work with Robert Vince, S. Bittner and S. Gurwara on the adenosine analog acycloadenosine which showed promising antiviral activity. Later, Schaffer joined Burroughs Wellcome and continued the development of aciclovir with pharmacologist Gertrude B. Elion. A U.S. patent on aciclovir listing Schaffer as inventor was issued in 1979.
Vince later went on to invent abacavir, an nRTI drug for HIV patients. Elion was awarded the 1988 Nobel Prize in Medicine, partly for the development of aciclovir. Dr. Richard Whitley, a University of Alabama at Birmingham researcher and pioneer in antiviral therapy, was the first to successfully use the drug in humans.
- Subject to the same conditions as before
- "Zovirax (acyclovir) dosing, indications, interactions, adverse effects, and more". Medscape Reference. WebMD. Retrieved 5 February 2014.
- de Clercq, Erik; Field, Hugh J (5 October 2005). "Antiviral prodrugs – the development of successful prodrug strategies for antiviral chemotherapy". British Journal of Pharmacology 147 (1) (Wiley-Blackwell, published January 2006). pp. 1–11. doi:10.1038/sj.bjp.0706446. PMC 1615839. PMID 16284630
- Rossi, S, ed. (2013). Australian Medicines Handbook (2013 ed.). Adelaide: The Australian Medicines Handbook Unit Trust. ISBN 978-0-9805790-9-3.
- Joint Formulary Committee (2013). British National Formulary (BNF) (65 ed.). London, UK: Pharmaceutical Press. ISBN 978-0-85711-084-8.
- Elad S, Zadik Y, Hewson I, et al. (August 2010). "A systematic review of viral infections associated with oral involvement in cancer patients: a spotlight on Herpesviridea". Support Care Cancer 18 (8): 993–1006. doi:10.1007/s00520-010-0900-3. PMID 20544224.
- Worrall, G (July 1996). "Evidence for efficacy of topical acyclovir in recurrent herpes labialis is weak." (PDF). BMJ (Clinical research ed.) 313 (7048): 46. doi:10.1136/bmj.313.7048.46a. PMC 2351426. PMID 8664786.
- Graham Worrall (6 Jan 1996). "Acyclovir in recurrent herpes labialis". BMJ 312 (7022): 6. doi:10.1136/bmj.312.7022.6. PMC 2349724. PMID 8555890. – Editorial
- Mascolinli, M; Kort, R (June 2010). "5th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention: summary of key research and implications for policy and practice - biomedical prevention" (PDF). Journal of the International AIDS Society. 13 Suppl 1 (Suppl 1): S4. doi:10.1186/1758-2652-13-S1-S4. PMC 2880255. PMID 20519025.
- "GLOBAL ACYCLOVIR Acyclovir 400mg and 800mg tablets". Medsafe. GLOBAL PHARMACEUTICALS LTD. 28 April 1999.
- "PRODUCT INFORMATION NAME OF THE DRUG OZVIR TABLETS" (PDF). TGA eBusiness Services. Ranbaxy Australia Pty Ltd. 26 August 2011. Retrieved 6 February 2014.
- Razonable, RR (October 2011). "Antiviral drugs for viruses other than human immunodeficiency virus" (PDF). Mayo Clinic proceedings. Mayo Clinic 86 (10): 1009–26. doi:10.4065/mcp.2011.0309. PMC 3184032. PMID 21964179.
- Brigden D, Rosling AE, Woods NC (July 1982). "Renal function after acyclovir intravenous injection". The American Journal of Medicine 73 (1A): 182–5. doi:10.1016/0002-9343(82)90087-0. PMID 6285711.
- Sawyer MH, Webb DE, Balow JE, Straus SE (June 1988). "Acyclovir-induced renal failure. Clinical course and histology". The American Journal of Medicine 84 (6): 1067–71. doi:10.1016/0002-9343(88)90313-0. PMID 3376977.
- Baselt, RC (2008). Disposition of toxic drugs and chemicals in man (8th ed. ed.). Foster City, CA: Biomedical Publications. p. 29-31. ISBN 9780962652370.
- "Acyclovir (acyclovir) Capsule Acyclovir (acyclovir) Tablet [Genpharm Inc.]". DailyMed. Genpharm Inc. November 2006. Retrieved 5 February 2014.
- "Aciclovir Tablets BP 400mg - Summary of Product Characteristics (SPC)". electronic Medicines Compendium. Actavis UK Ltd. 20 August 2012. Retrieved 5 February 2014.
- O'Brien, JJ; Campoli-Richards, DM (1989). "Acyclovir. An updated review of its antiviral activity, pharmacokinetic properties and therapeutic efficacy". Drugs 37 (3): 233–309. PMID 2653790.
- Wagstaff, AJ; Faulds, D; Goa, KL (January 1994). "Aciclovir. A reappraisal of its antiviral activity, pharmacokinetic properties and therapeutic efficacy.". Drugs 47 (1): 153–205. doi:10.2165/00003495-199447010-00009. PMID 7510619.
- Sweetman, S, ed. (7 August 2013). "Aciclovir". Martindale: The Complete Drug Reference. London, UK: Pharmaceutical Press. Retrieved 6 February 2014.
- Aciclovir Tablets BP 400mg - Summary of Product Characteristics (SPC) - (eMC)
- Garrison, Tom (1999). Oceanography: An Invitation to Marine Science, 3rd ed. Belmont, CA: Wadsworth Publishing Company. p. 471.
- Sepčić, K. (2000). "Bioactive Alkylpyridinium Compounds from Marine Sponges". Toxin Reviews 19 (2): 139–160. doi:10.1081/TXR-100100318.
- Laport, M. S.; Santos, O. C.; Muricy, G. (2009). "Marine sponges: Potential sources of new antimicrobial drugs". Current pharmaceutical biotechnology 10 (1): 86–105. PMID 19149592.
- Schaffer, Howard; Robert Vince, S. Bittner, S. Gurwara (1971). "Novel substrate of adenosine deaminase". Journal of Medicinal Chemistry 14 (4): 367–369. doi:10.1021/jm00286a024. PMID 5553754.
- Elion, Gertrude; Furman, Fyfe, Miranda, Beauchamp and Schaffer (1977). "Selectivity of action of an antiherpetic agent, 9-(2-hydroxyethoxymethyl)guanine". Proc Natl Acad Sci USA 74 (12): 5716–5720. doi:10.1073/pnas.74.12.5716. PMC 431864. PMID 202961.
- US 4146715
- Vince, R. "A brief history of the development of Ziagen" Chemtracts 2008, 21, 127–134.
- Saugata Hazra, Manfred Konrad, Arnon Lavie. The sugar ring of the nucleoside is required for productive substrate positioning in the active site of human deoxycytidine kinase (dCK): implications for the development of dCK-activated acyclic guanine analogues. PMID: 20684612
- Harvey Stewart C. in Remington’s Pharmaceutical Sciences 18th edition: (ed. Gennard, Alfonso R.) Mack Publishing Company, 1990. ISBN 0-912734-04-3.
- Huovinen P., Valtonen V. in Kliininen Farmakologia (ed. Neuvonen et al.). Kandidaattikustannus Oy, 1994. ISBN 951-8951-09-8.
- Périgaud C., Gosselin G., Imbach J. -L.: Nucleoside analogues as chemotherapeutic agents: a review. Nucleosides and nucleotides 1992; 11(2–4)
- Rang H.P., Dale M.M., Ritter J.M.: Pharmacology, 3rd edition. Pearson Professional Ltd, 1995. 2003 (5th) edition ISBN 0-443-07145-4; 2001 (4th) edition ISBN 0-443-06574-8; 1990 edition ISBN 0-443-03407-9.