Aciclovir 400 Mg (Acyclovir)

Last Updated on 07/01/2026

Aciclovir 400 Mg is a drug that contains Acyclovir, an FDA-approved composition for the treatment of herpes and chicken pox in patients aged 2 years and older. The medication is available at pharmacies only with a prescription.

Uses Of Aciclovir 400 Mg

Usually, doctors prescribe Aciclovir 400 Mg for the treatment of:

• Chicken Pox
• Herpes: Herpes Zoster (Shingles), Herpes Labialis (Cold sores) and genital herpes.

How To Take Aciclovir 400 Mg

• Take some light food for the first dose of the day.
• Keep not more than 4 hours gap between two intakes a day.
• 4-5 times the intake of the drug is usually prescribed.
• Swallow the pill with water without breaking/chewing it.
• Maintain hygiene to restrict the contamination of the infection.

Dosage Of Aciclovir 400 Mg

The dosage of Aciclovir is extremely critical, especially for children between 2 years and 12 years. The dosage in such cases depends on the weight of the patient, and hence, the doctor’s guidance has to be followed strictly. Information related to the dosage has been stated below:

Chicken Pox:

• Dose can be given to patients more than 2 years old.
• For a weight of 40kg or less, the prescribed dosage is 20mg/kg, 4-times a day for 5 days.
• For patients weighing more than 40kg, the dosage is 800mg, 4-times a day for 5 days.

Cold Sore and Shingles:

• Above the age must take 800mg, 4 times a day for 7-10 days.
• Children between 2 years and 12 years must take 20mg/kg, 4 times a day for 7 days.
• Children below the age of 2 years must not take the pill.

Genital Herpes:

• Children more than 12 years and adults must take 200mg of Aciclovir, 5 times a day.
• Dosage duration is 10 days, and the gap between each medicine intake is 4 hours.
• Dosage for children 2-12 years is 20mg/kg, 5 times a day for 10 days.
• Do not use Aciclovir in kids less than 2 years without asking your doctor.

Dosage Monitoring Of Aciclovir 400 Mg:

• Gaps between intakes: Since the frequency of taking Aciclovir is 4-5 times a day, never give more than a 4-hour gap between two doses.
• Missed Dose: Try not to miss a dose. If you miss it, skip it and move to the next dose.
• Overdose: Overdosing can cause several issues for your kidneys. Hence, never overdose, and if done by mistake, call a doctor for emergent remedy.

Side Effects Of Aciclovir 400 Mg

Aciclovir can cause some side effects that can be mild to intense. In some of the cases, call the doctor immediately. Take consultation from a doctor about when to call him for side effects, as you take the medicine. Here is a list of side effects, you can face:

• Dehydration
• Contamination
• Fever
• Issues with the nervous system
• Immune deficit
• Skin rashes
• Nausea
• Dizziness
• Malfunction in the Kidney.

Precautions And Warnings:

Go through the precautionary measures sincerely and follow them for your safety and the safety of your close ones:

Need Prior consultations:

• You can face issues if there is no dosage adjustment done in case you are undergoing dialysis. If you are in such a situation, consult your doctor before starting the treatment.
• Your immune system can fall a lot. In case you have some blood disorders like thalassemia or HIV, then consult your doctor first about them.
• In case you are in the 2^nd or 3^rd trimester, Aciclovir can cause a minor hazard to your foetus. Hence, you need a dosage adjustment.

Never take:

• Aciclovir can affect the foetus when you are in 1^st Hence, if you are in 1st trimester, avoid taking the pill.
• Alcohol can create a burning sensation in your intestine and can also create an anomaly in kidney function.

Never Do:

• Avoid sexual intimacy during your treatment with Aciclovir.
• Never drive a car while taking a dose of Aciclovir.
• Never share your things with family and friends to avoid contamination.

FAQs

Q. Can Aciclovir 400 Mg Cause Constipation?

No, there is no such report available at the clinics. If you are facing it for the first time, report the same to your doctor.

Q. When To Start The Treatment With Aciclovir?

Try to start the treatment of herpes and chicken pox as fast as you can. This will prevent the contamination and will help with fast recovery.

Q. Is Fever A Side Effect Of Aciclovir?

No, you can face a fever from chicken pox, but it is not a side effect of Aciclovir. If you are facing a fever for herpes, call your doctor.

Q. Can I Get Aciclovir Without A Prescription?

No, you cannot get Aciclovir without a prescription. FDA rules says that no pharmacy must give Aciclovir without a prescription.

Q. Where To Buy Aciclovir 400 Mg?

Powpills is a safe and widely available online pharmacy to get Aciclovir. Carry and show your prescription for obtaining the drug.

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