Getting the correct acyclovir dosage is like following a recipe - too little won't work properly, too much might cause problems, but just the right amount can work wonders. Whether you're treating cold sores, shingles, or chickenpox, understanding your dosage is crucial for success.

Standard Acyclovir Dosages for Common Conditions

Doctors typically prescribe acyclovir in these amounts:

• Cold sores (herpes labialis): 400 mg 3 times daily for 5 days


• Genital herpes (first outbreak): 200 mg every 4 hours (5 times daily) for 10 days


• Genital herpes (recurrences): 400 mg 3 times daily for 5 days


• Shingles (herpes zoster): 800 mg every 4 hours (5 times daily) for 7-10 days


• Chickenpox (in adults): 800 mg 4 times daily for 5 days

Important Timing Considerations

When you take acyclovir matters just as much as how much you take:

• Start at the first sign - For cold sores, this means when you feel that first tingle or itch


• Space doses evenly - If taking 3 times daily, aim for every 8 hours (like 7am, 3pm, 11pm)


• With or without food? - Can be taken either way, but food may help if you get nauseous

Special Dosage Adjustments

For Children

Dosing is based on weight for chickenpox (20 mg/kg 4 times daily, max 800 mg per dose). Always use pediatric formulations when available.

For Kidney Problems

Your doctor may reduce your dose if you have kidney issues, since acyclovir is eliminated through the kidneys.

For Elderly Patients

Older adults often need adjusted doses due to natural kidney function decline.

Common Dosage Mistakes to Avoid

• Doubling up - If you miss a dose, don't take two at once


• Stopping early - Finish the full course even if symptoms improve


• Using leftover medication - Different conditions require different doses


• Crushing tablets - Unless directed, swallow whole with water

What If You Miss a Dose?

Here's what to do based on when you remember:

Time Since Missed Dose	Action
Less than 2 hours late	Take it now
More than 2 hours late	Skip it and continue schedule
Next dose is due soon	Just take that one

Dosage for Prevention (Suppression Therapy)

Some people take acyclovir daily to prevent outbreaks:

• Typical suppressive dose: 400 mg twice daily


• Effectiveness: Can reduce outbreaks by 70-80%


• Duration: Often taken for 6-12 months at a time

Different Forms, Different Rules

Acyclovir comes in several forms with different dosing:

• Tablets (200/400/800 mg): Most common for adults


• Oral suspension: Better for children or swallowing difficulties


• Topical cream: Applied 5 times daily (not for genital areas)


• IV form: Used in hospitals for severe cases

How Long Until You See Results?

Most people notice improvement within 24-48 hours, but full effects take:

• Cold sores: 2-3 days to stop progression


• Shingles: 3-5 days for pain reduction


• Chickenpox: 1-2 days for fever improvement

When to Call Your Doctor About Dosage

Contact your healthcare provider if:

• You experience severe side effects


• Symptoms worsen after 3 days


• You're unsure about the correct dose


• You have special circumstances (pregnancy, other medications)

For comprehensive acyclovir dosage information tailored to your specific needs, always consult with your doctor or pharmacist.

Final Thoughts

Remember that acyclovir dosage isn't one-size-fits-all. What works for your friend's cold sore might not be right for your shingles. The most important things are to start treatment early, follow your prescribed schedule carefully, and complete the full course of medication. When used correctly at the proper dosage, acyclovir can significantly reduce both the severity and duration of viral outbreaks.