Aciclovir

Key points

• Aciclovir belongs to the nucleoside analogue class of antiviral medicines.
• The tablet is supplied in 200 mg, 400 mg and 800 mg strengths.
• The onset time is 24 to 48 hours.

What aciclovir is used for

Aciclovir targets herpes viruses specifically. It is used for Herpes Simplex, including cold sores or genital herpes. It is also used for Varicella Zoster Infection, the virus that causes shingles and chickenpox. In recurrent herpes simplex, treatment may shorten how long symptoms last and reduce their severity. The tablet is taken by mouth, so it treats infection throughout the body. That helps with infections such as genital herpes and shingles, which can affect areas beyond the skin. It belongs to the Antivirals category of medicines.

How aciclovir works

Aciclovir prevents the virus from multiplying. It resembles a DNA building block, so the virus takes it up in place of the normal component. Inside an infected cell, aciclovir is converted to its active form. The active form is then added to the viral DNA strand as it grows. This stops the chain from extending, so fewer new virus particles are made. By limiting replication, aciclovir reduces the spread of the virus to new cells. With fewer new virus particles, the body can control the infection more effectively and sores or blisters can heal. The duration is 4 to 5 hours.

Aciclovir tablets

Aciclovir is supplied as a tablet. The product is Aciclovir. The tablet is taken by mouth and is the oral form supplied for treatment at home during an outbreak. It acts systemically, so it is not applied directly to a sore. Pharmacy partners in India ship orders to Malaysia in discreet packaging.

Before starting aciclovir

Do not take aciclovir if you have had a hypersensitivity reaction to aciclovir. Adequate hydration is advised during treatment. Dehydration can change the way the body handles aciclovir. Aciclovir is cleared by the kidneys, so kidney function may need review before treatment starts. Pre-existing kidney disease is an important factor to discuss with your healthcare professional. Begin treatment as early as possible in an outbreak. In pregnancy, aciclovir is used only when the benefits to the mother outweigh the potential risks. Aciclovir passes into breast milk, so it is used with caution during breastfeeding. Dosage for children is adjusted.

Side effects and interactions

Most people tolerate aciclovir well. Minor side effects include nausea, diarrhoea and headache. Rash and fatigue can also occur. Acute renal failure and neurological symptoms are serious side effects and require immediate medical attention. Tell your healthcare professional about all medicines you take, including over-the-counter products and probenecid; aciclovir interacts with probenecid. Aciclovir can interact with medicines that change kidney function. Your healthcare professional can review your full medication list.

Further reading

• Aciclovir (AN) | healthdirect
• Aciclovir
• Acyclovir: MedlinePlus Drug Information
• Acyclovir - StatPearls - NCBI Bookshelf