Aciclovir (ACV)
Aciclovir, also known as acyclovir or by its brand name Zovirax, is an antiviral medication primarily used to treat infections caused by various strains of the herpes virus. Manufactured by GlaxoSmithKline, it is effective in managing conditions such as chickenpox, shingles, and herpes simplex infections affecting the mouth, lips, and genitals. Though it helps in alleviating symptoms and promotes healing, aciclovir is not a cure and does not prevent the transmission of the virus.
Aciclovir operates by selectively targeting the herpes virus, inhibiting its ability to replicate without harming normal cells. Discovered in 1974 through innovative research methods, it received FDA approval for treating herpes infections in 1982. While it is widely used, aciclovir can cause side effects ranging from mild symptoms like upset stomach to more severe reactions requiring immediate medical attention. Dosage varies based on the patient's age and the specific condition being treated, highlighting the importance of following a physician's guidance.
Aciclovir (ACV)
Aciclovir, also known acyclovir, is an antiviral medication most commonly used to treat various strains of herpes. GlaxoSmithKline manufactures aciclovir under the brand name Zovirax. This drug is also known as acycloguanosine or ACV. It is an analog of quinine, which means it is similar to the drug quinine in composition but has different effects.
Aciclovir is most commonly prescribed to treat chickenpox (varicella) and shingles (herpes zoster), as well as herpes simplex infections of the mouth, lips, genitals, and anus. With the exception of herpes zoster, these conditions are infectious and spread via contact with the fluid in the sores or blisters that form on infected patients. The World Health Organization (WHO) estimates that as many as 3.7 billion people, or 67 percent of the world's population, carry the herpes simplex-1 form of the virus, which causes mouth sores commonly known as cold sores. WHO estimates that 417 million people, or about 11 percent of the total population, are infected with the herpes simplex-2 virus. This form of the virus is responsible for sexually transmitted genital herpes.
Aciclovir is not considered a cure for these conditions but it helps with healing, minimizes pain from the sores, and reduces the risk of disease complications. It can be used to prevent recurring outbreaks in those who have already experienced a herpes infection, and is sometimes used to prevent the immunocompromised—those individuals with lowered immunity, such as those undergoing chemotherapy or those who are HIV positive—from contracting a herpes infection.
History
Aciclovir was discovered in 1974 in the Wellcome Research laboratories near London. Its discovery was the result of the use of relatively new processes for drug research promoted by American biochemist Gertrude Elion (1918-1999) and American physician George Hitchings (1905-1998). Prior to their groundbreaking collaboration, which began in the 1940s, most drug research involved attempts to alter natural substances. Elion and Hitchings applied knowledge of chemical compounds and the systems of the human body. They sought ways to use biochemical effects to control the undesirable effects of bacteria, cancer cells, and viruses on the body without damaging normal cells. This new research technique resulted in the development of many new drug therapies, including aciclovir. As a result, Elion and Hitchings were awarded the Nobel Prize for Physiology or Medicine in 1988.
Continued research into the drug refined the drug's usefulness. In 1982, the US Food and Drug Administration (FDA) approved aciclovir for use in the treatment of various herpes infections.
How It Works
Aciclovir is very selective, as it only affects the herpes virus. It has a low rate of cytotoxicity, or toxicity toward normal cells. It works by interfering with the reproduction of the virus’s cells. A polymerase (enzyme) in the DNA of herpes virus cells activates the drug, which in turn acts on the DNA of the virus cells to prevent them from replicating. The interaction between the drug and the virus causes the drug to become more potent against the virus, eventually leading to a complete shutdown of the virus's ability to grow.
The DNA of normal cells does not activate aciclovir. Therefore, the drug does not affect or damage these cells.
Indications
Available by prescription as a tablet, capsule, injectable or suspension liquid, aciclovir is one of the most widely used drugs in the world, according to WHO. It is used to help heal the sores caused by chickenpox (varicella) as well as shingles (herpes zoster), an infection that sometimes occurs in people who have already had chickenpox.
Aciclovir is also used to treat genital herpes and herpes infections that occur on the skin, mouth, eyes, or nose. Aciclovir is sometimes used to prevent repeat outbreaks in an individual with genital herpes. However, the drug is not a cure and does not necessarily prevent the infected person from spreading the disease to another party. Aciclovir can also be used to help prevent a herpes infection in a person whose immune system is weakened by chemotherapy or another disease, such as HIV.
Side Effects
While aciclovir can greatly lessen the discomfort and duration of a herpes infection, it can also cause side effects. Some of the most serious ones include hives, additional rash or blisters, increased itching, difficulty breathing or swallowing, swelling of the face or lower limbs, hoarseness, weakness, fast heartbeat, blood in the urine or stools, stomach pains, hallucinations, aggressive behavior, difficulty speaking, numbness or tingling in the limbs, uncontrollable shaking, seizures, or loss of consciousness. The development of any of these conditions while taking aciclovir should be reported to a doctor immediately.
Less serious side effects include upset stomach, vomiting, dizziness, tiredness, joint pain, vision changes, and hair loss.
It is possible to overdose on aciclovir. Symptoms of an overdose include agitation, seizures, extreme fatigue, and lack of consciousness. If an overdose is suspected, emergency services should be contacted immediately.
Dosages
Dosing depends on the age of the patient and form of herpes being treated and will be determined by the prescribing physician.
In general, adults and children 12 years of age and older being treated for genital herpes receive 200 mg of the drug per dose, given four to five times per day for ten days. Doses to prevent a recurrence of genital herpes in patients 12 years of age and over are 200 to 400 mg given two to five times a day, for between five days and a year, depending on the frequency of outbreaks. For the treatment of chickenpox or shingles, patients weighing more than 40 kilograms (88 pounds) are given 800 mg four times a day for five days. Doses for children under the age of 12 or under 40 kilograms (88 pounds) are determined by a physician.
Bibliography
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