Acyclovir is a popular antiviral drug with selective activity against herpes simplex viruses of types 1 and 2, Varicella zoster and Epstein-Barr viruses, and cytomegalovirus.


According to the instructions, the medicine is prescribed for the treatment of the following diseases:

  • primary and recurrent genital herpes, which is severe;
  • herpes zoster caused by the Varicella zoster virus;
  • recurrent and primary herpes simplex with damage to the mucous membranes and skin, caused by the virus Herpes simplex types 1 and 2, in patients with impaired immunity;
  • herpes zoster, accompanied by eye damage.

How does it work?

The active component of Acyclovir has antiviral and immunostimulating effects, effectively acting on Epstein-Barr viruses, Varicella zoster, Herpes simplex types 1, 2 and cytomegalovirus.

The mechanism of action is based on the formation of “defective” viral DNA, which blocks the reproduction of the virus.

With the herpes virus, the drug stops the formation of rash elements while accelerating the formation of crusts. In addition, the drug reduces the intensity of pain in the acute phase of herpes zoster, the likelihood of visceral complications and cutaneous dissemination.


  • Lactation period;
  • Hypersensitivity to the components of acyclovir or valacyclovir;
  • Children under 3 years of age (tablets)/

Use with caution:

  • pregnancy;
  • treatment of the elderly;
  • kidney dysfunction;
  • a history of various neurological reactions in response to taking cytotoxic drugs.

How to take Acyclovir?

The tablets should be taken with meals. The dosage regimen is set by the doctor individually.

In the treatment of infections of the mucous membranes and skin caused by Herpes simplex types 1 and 2, adults take this drug for 5 days. A single dosage is 1 tablet 200 mg, the frequency of administration is 5 times a day, observing a four-hour interval between doses.

  1. In some cases, longer treatment (up to ten days) and doubling of the single dosage may be required;
  2. Acyclovir, according to the instructions, is most effective in cases where treatment is started immediately after the infection is detected;
  3. To prevent possible recurrence of infections, take one tablet (200 mg) with an interval of 6 hours.

In the treatment of chickenpox (infections caused by the Varicella zoster virus), 2 tablets of Acyclovir (400 mg each) are taken 5 times a day for 7-10 days. For children, the dosage is usually calculated based on body weight.

For the treatment of shingles (infections caused by the Herpes zoster virus), take the same dosage as for treating chickenpox. The duration of treatment is 5 days. Children over 3 years of age are usually given an adult dosage.

Elderly people need to observe the water regimen, and the recommended dose of the drug for adults should be reduced.

Can Acyclovir cause side effects?

As a rule, these tablets do not cause side effects even in children. Some patients with impaired renal function or other concomitant diseases may experience:

  • skin rashes;
  • nausea;
  • stomach ache;
  • headaches;
  • vomiting;
  • diarrhea;
  • insomnia;
  • dizziness;
  • confusion of thoughts;
  • sleepiness;
  • a sense of alienation.

Very rarely, the drug could cause temporary convulsions, psychosis, hallucinations, difficulty breathing, increased hair loss and changes in laboratory parameters for liver and kidney studies.

Can I overdose on this medicine?

According to reviews, Acyclovir tablets do not cause overdose attacks when you take up to 5 g of the active substance at a time. This has been proven by experts, but there is no data on the intake of a higher concentration of the compound. If you have a feeling of uncertainty, or the body still exhibits some negative reactions, then it is better to immediately consult a specialist.

Can I use it during pregnancy and lactation?

  • Pregnancy: therapy can be carried out under medical supervision after assessing the ratio of the expected benefit with the possible risk;
  • Lactation period: the drug is contraindicated.

Can I take Acyclovir with other medicines?

Co-administration of the tablet form with external agents (ointments, creams) enhances the therapeutic effect.

The excretion of the active substance is slowed down with simultaneous treatment with drugs that lower the level of uric acid in the blood. It is not recommended to combine this antiviral with drugs that have a nephrotoxic effect.

Otherwise, the antagonism of this medicine is still not well understood.

Acyclovir reviews

Most reviews about this drug are positive. The drug is considered effective, inexpensive and accessible.

Some patients say that improvement comes quickly, while others point out that symptom relief is not immediate.

Users also note that this medicine can cause side effects (edema, dermatoses).

The tablets are usually used in cases where it was not possible to stop the symptoms of herpes by external means. Users note that the best results are achieved when using the drug with the first symptoms of the disease.