Further introduction about Acyclovir

Posted by beauty33 on January 29th, 2022

Pharmacopoeia standards

Source (name), content (potency)

This product is 9-(2-hydroxyethoxymethyl)guanine. Calculated as dry product, the content of C8H11N5O3 shall not be less than 98.0%.

Traits

This product is white crystalline powder; it is odorless and tasteless.

This product is slightly soluble in glacial acetic acid or hot water, almost insoluble in ether or dichloromethane; it is easily soluble in sodium hydroxide test solution.

Drug description

Pharmacology and Toxicology

Antiviral drugs. It can inhibit herpes simplex virus, varicella-zoster virus, cytomegalovirus, etc. in vitro. After the product enters herpes virus-infected cells, it competes with deoxynucleosides for viral thymidine kinase or cell kinase. The drug is phosphorylated into activated acyclovir triphosphate, and then it inhibits virus replication in two ways:

? Interfere with viral DNA polymerase and inhibit virus replication;

? Under the action of DNA polymerase, it combines with the growing DNA chain, causing the extension of the DNA chain to be interrupted.?The product has a special affinity for viruses, but has low toxicity to mammalian host cells. In vitro cell transformation assays have reported carcinogenicity, but animal experiments have not found evidence of carcinogenicity. Certain animal experiments have shown that high concentrations of drugs can cause mutations, but there is no basis for chromosomal changes.

The carcinogenic and mutagenic effects of this product are not yet clear. Large-dose injections can cause animal testicular atrophy and sperm count reduction. The drug can pass through the placenta. Animal experiments have confirmed that it has no effect on embryos.

Pharmacokinetics

Oral absorption is poor, about 15% to 30% is absorbed by the gastrointestinal tract. Eating has no obvious effect on blood drug concentration. It can be widely distributed in various tissues and body fluids, including brain, kidney, lung, liver, small intestine, muscle, spleen, breast milk, uterus, vaginal mucosa and secretions, cerebrospinal fluid and herpes fluid. The concentration is high in the kidney, liver and small intestine, and the concentration in the cerebrospinal fluid is about half of the concentration in the blood. The drug can pass through the placenta. 200 mg and 400 mg were taken orally every 4 hours, and the peak plasma concentration (Cmax) after 5 days was 0.6 mg/L and 1.2 mg/L, respectively. The protein binding rate of this product is low (9%?33%). Metabolized in the liver, the main metabolites account for 9% to 14% of the dose and are excreted in the urine. The blood elimination half-life (tl/2β) is about 2.5 hours. When the creatinine clearance rate is 50?80ml/min and 15?50ml/min, the blood elimination half-life (tl/2β) is 3.0 hours and 3.5 hours, respectively. The blood elimination half-life (tl/2β) of anuria is as long as 19.5 hours, and it is reduced to 5.7 hours during hemodialysis. The product is mainly excreted through the kidneys through glomerular filtration and tubular secretion. About 14% of the drugs are excreted in urine in their original form, and the excretion rate through feces is less than 2%. Exhaled breath contains trace amounts of drugs. About 6 hours of hemodialysis removes 60% of the drug in the blood. Peritoneal dialysis cleared very little.

Indications

1. Herpes simplex virus infection: Orally used for the initial and recurring cases of genital herpes virus infection; for recurrent cases, the product is used for prevention. Injections are used for people with immunodeficiency. Treatment of initial and recurrent mucosal skin infections and prevention of recurrent cases; also used in the treatment of herpes simplex encephalitis.

2. Herpes zoster: Orally used for the treatment of herpes with normal immune function and mild cases of immunodeficiency. The injection is used for the treatment of severe herpes patients with immunodeficiency.

3. Treatment of chickenpox in immunodeficiency patients.

4. Topically used for the initial treatment and recurrence of early genital herpes infection caused by herpes simplex virus and self-limited mucosal skin herpes simplex in immunodeficiency patients.

5. Use its sodium salt to treat acute retinal necrosis. Nucleotide antiviral drugs, used to treat:

? Herpes simplex keratitis;

?Herpes simplex;

?Herpes;

? Treat acute retinal necrosis with its sodium salt. Mainly used for superficial and deep keratitis caused by herpes simplex virus and herpes zoster virus.

Clinical application

1. Herpes simplex virus infection: It is used for the initial and recurring cases of genital herpes virus infection, and the product is taken orally for prevention of recurrent cases.

2. Herpes zoster: used for the treatment of patients with normal immune function and mild cases of immunodeficiency.

3. Treatment of chickenpox in immunodeficiency patients.

Acyclovir is catalyzed by the viral thymidine kinase (TK enzyme) and the kinase in the cell in the infected cells to generate acyclovir triphosphate, which inhibits the viral DNA polymerase. In addition, once acyclovir triphosphate is incorporated into the DNA that the virus is elongating, it will cause DNA synthesis to stop. Drug-resistant virus strains have been found clinically and experimentally, and the formation of drug resistance is related to the mutation of the viral thymidine kinase gene.

Adverse reactions

1. Common adverse reactions: inflammation or phlebitis at the injection site, skin itching or urticaria.

2. Rare adverse reactions: oral administration of skin itching, long-term administration of occasional menstrual disorders. During injection, especially intravenous injection, acute renal insufficiency, hematuria and hypotension are rare.

3. Rare adverse reactions: coma, confusion, hallucinations, epilepsy and other central nervous system symptoms.

4. Adverse reactions of topical medications: 28% of them have mild pain, burning and tingling, 4% of itching, and 0.3% of rash.

5. If the following symptoms persist or are obvious, attention should be paid to: joint pain, diarrhea, headache, nausea, vomiting, dizziness (more short-term medication) due to long-term oral administration of the product. Acne and insomnia are rare with long-term medication; loss of appetite is rare with short-term medication. Mild headaches are common with injections, and hyperhidrosis is rare. The product is less toxic to cells and has a wide range of safety. There were no obvious adverse reactions to topical eye drops and creams. Intravenous administration requires slow infusion for more than 1 hour or continuous slow infusion, generally no response. Sometimes rashes and nettles can be seen.

About us

Creative Biolabs provides high quality products and services to the global biology researcher at inception as their lofty mission. After more than ten years of innovation and development, we have grown into a prestigious CRO in the industry. In addition to providing researchers with various products such as coronavirus release, CoV, darunavir sars, fleximer, etc. We have also accumulated a lot of experience in drug discovery and vaccine development. Especially in the field of antiviral drugs and vaccines, our drug discovery, vaccine design, preclinical evaluation of drugs and vaccines, and in vitro diagnostic services are at the world-leading level.