Acyclovir

Description

Acyclovir is an antiviral medication primarily used to treat infections caused by certain types of viruses, particularly the herpes simplex virus and varicella-zoster virus. It works by inhibiting the replication of viral DNA, which helps to manage outbreaks of infections such as genital herpes, cold sores, and shingles.

Uses / Indications

• Genital herpes (initial and recurrent episodes)
• Cold sores (herpes labialis)
• Shingles (herpes zoster)
• Chickenpox (varicella) in children and adults
• Prevention of herpes infections in immunocompromised patients

Dosage and Administration

Adults:
Typically, for the treatment of genital herpes: 400 mg three times daily for 7 to 10 days.

Children (aged 2 years and older):
Dosage will vary based on weight and the type of infection; consult a healthcare provider.

Note: Dosage may vary based on specific medical conditions or doctor’s advice.

How It Works (Mechanism of Action)

Acyclovir is a nucleoside analogue that selectively inhibits the replication of viral DNA by targeting the viral enzyme DNA polymerase. This action prevents the virus from multiplying and spreading, aiding in the resolution of the infection.

Side Effects

Common side effects:

• Nausea
• Diarrhea
• Headache
• Fatigue

Rare/serious side effects:

• Kidney problems (increased creatinine levels)
• Severe allergic reactions (rash, itching, swelling)
• Neurological effects such as tremors or seizures (in highly excessive doses)

Seek medical attention if serious side effects occur.

Precautions / Warnings

• Inform your doctor if you have kidney disease or are pregnant/breastfeeding
• Hydrate well to help prevent kidney stress
• Monitor for symptoms of dehydration, especially if experiencing nausea or vomiting

Drug Interactions

May interact with:

• Probenecid (may increase acyclovir levels in the blood)
• Other nephrotoxic medications (may increase risk of kidney damage)
• Vaccines (live vaccines should be avoided during treatment)

Always inform your healthcare provider about any other medications or supplements you’re taking.

Storage Instructions

• Store at room temperature (20°C–25°C / 68°F–77°F)
• Keep away from moisture and direct light
• Keep out of reach of children

Missed Dose / Overdose

Missed a dose?
Take it as soon as you remember. If it’s almost time for your next dose, skip the missed dose. Do not double up.

Overdose symptoms:

• Nausea and vomiting
• Confusion or hallucinations
• Seizures
• Increased urination or kidney issues

Contact a poison control center or seek emergency medical help immediately.

Contraindications

• Allergic reaction to acyclovir or valacyclovir
• Severe renal impairment (without dose adjustment)

Brand Names / Alternatives

• Zovirax
• Sitavig (buccal tablets for cold sores)
• Generic name: Acyclovir