Aciclovir is an antiviral medicine
which means it is designed to act against viruses. Aciclovir is specifically
designed to treat the herpes simplex virus that causes cold sore symptoms, as
well as some other closely related viruses, such as the virus that causes
chicken pox and shingles.
Aciclovir works by interrupting the
normal process of viral replication – when viruses copy themselves inside your
cells. This helps reduce the number of viruses in your body and in turn helps
reduce the severity of symptoms experienced. Since the virus reproduces very
early in the infection, you will benefit most from treatment if you take
Aciclovir Tablets as soon as the first symptoms appear, ideally within 5 days
of their appearance.
This medication does not cure cold
sores as the virus continues to live in the body even after an outbreak, but it
works to reduce the severity and length of the outbreak whilst decreasing the
risk of transmitting the virus to other people. Aciclovir starts working almost
immediately after you start taking it and is effective in reducing the healing
time and reducing the risk transmitted to other people.
Cold Sores (Herpes Labialis):
Dose: One 200mg tablet five times a day. Your doctor may advise you to take two 200mg tablets (equivalent to one 400mg tablet) five times a day.
Frequency: Take one dose every four hours while you are awake. For example, at 7 am, 11 am, 3 pm, 7 pm, and 11 pm.
Duration: Usually for five days, but your doctor may extend this period if needed.
Important: Start taking aciclovir as soon as you feel the tingling, itching, or burning sensation that usually precedes a cold sore, or when the blisters first appear.
Genital Herpes (Herpes Simplex Genitalis):
For treating an initial outbreak:
Dose: One 200mg tablet five times a day. Your doctor may advise you to take two 200mg tablets (equivalent to one 400mg tablet) five times a day.
Frequency: Take one dose every four hours while you are awake. For example, at 7 am, 11 am, 3 pm, 7 pm, and 11 pm.
Duration: Usually for five to ten days, or as directed by your doctor.
For preventing recurrent outbreaks (suppression):
Dose: One 400mg tablet twice a day. Your doctor may adjust this dose based on how often your outbreaks occur.
Frequency: Take one tablet in the morning and one in the evening, approximately 12 hours apart.
Duration: This can be for several months as prescribed by your doctor.
For treating a recurrent outbreak:
Dose: One 200mg tablet five times a day. Your doctor may advise you to take two 200mg tablets (equivalent to one 400mg tablet) five times a day.
Frequency: Take one dose every four hours while you are awake, for five days, or as directed by your doctor.
Important: Start taking aciclovir as soon as you notice the first signs or symptoms of a recurrence (e.g., tingling, itching, burning, or blisters).
Shingles (Herpes Zoster):
Dose: Two 400mg tablets (800mg) five times a day.
Frequency: Take one dose every four hours while you are awake and during the night. For example, at 7 am, 11 am, 3 pm, 7 pm, and 11 pm.
Duration: For seven to ten days, as directed by your doctor.
Important: Start taking aciclovir as soon as possible after the shingles rash appears, ideally within 72 hours, to get the maximum benefit.
General Advice:
Swallow the tablets whole with a glass of water. If you have difficulty swallowing, some tablets can be dissolved in a small amount of water; stir and drink immediately.
Try to take your doses at the same times each day to maintain a consistent level of the medication in your body.
Complete the full course of treatment as prescribed by your doctor, even if your symptoms improve before the medication is finished. Stopping early may allow the virus to multiply again.
Drink plenty of fluids while taking aciclovir to help your kidneys work properly.
If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one.
Inform your doctor or pharmacist if you are taking any other medications, including over-the-counter medicines or herbal supplements, as they may interact with aciclovir.
Tell your doctor if you have any kidney problems as your dose may need to be adjusted.
If you experience any unusual side effects, such as allergic reactions (rash, itching, swelling, difficulty breathing), stop taking aciclovir and seek medical attention immediately. Other less serious side effects can occur; consult your doctor or pharmacist if you are concerned.
It is crucial to consult your doctor or pharmacist for personalized instructions on how to take aciclovir 400mg for your specific condition. They will consider your medical history and the severity of your infection to determine the most appropriate dosage and duration of treatment for you.
Medicines and their possible side effects can
affect individual people in different ways. The following are some of the side
effects that are known to be associated with this medicine. Just because a side
effect is stated here, it does not mean that all people using this medicine
will experience that or any side effect. While it is generally well-tolerated,
it can have a range of side effects. Here’s a detailed overview:
Common Side Effects
1. Nausea and Vomiting: Some patients may
experience gastrointestinal upset, including nausea and vomiting, particularly
after intravenous administration.
2. Diarrhoea: Diarrhoea is another common side
effect that may occur during treatment.
3. Headache: Mild to moderate headaches may occur
in some individuals.
4. Dizziness: Patients may experience dizziness or
light-headedness while taking acyclovir.
Less Common Side Effects
1. Rash: Skin rashes or hives may develop as a
reaction to the medication.
2. Fatigue: Some patients report feelings of
tiredness or fatigue.
3. Abdominal Pain: Mild abdominal discomfort can
occur.
4. Dehydration: High doses of intravenous acyclovir
may lead to dehydration, especially in patients with pre-existing kidney
issues.
Rare Side Effects
1. Neurotoxic Effects: Rarely, acyclovir can cause
neurotoxicity, particularly when high doses are administered. Symptoms may
include confusion, tremors, hallucinations, or seizures.
2. Renal Impairment: In some cases, acyclovir can
lead to kidney problems, especially when dehydration or rapid infusion occurs.
Monitoring renal function during treatment is essential.
3. Thrombocytopenia: A temporary decrease in
platelet count may occur, leading to a higher risk of bleeding or bruising.
4. Liver Enzyme Changes: Elevated liver enzymes may
be observed, indicating potential liver dysfunction.
For full information on side effects and correct
use, see the patient information leaflet. If any side effects concern you, or
you are experiencing any of the side effects mentioned in the patient
information leaflet whilst taking this medication, please contact our clinical
team or speak to your GP.
If you have a damaged or weakened immune system (immunocompromised) you
should seek medical advice before taking Aciclovir and at any time you
experience a cold sore or other infection.
If you are elderly, renally impaired, pregnant or breastfeeding, you
should seek medical advice before taking Aciclovir.
Get emergency medical help if you have signs of an allergic reaction to
this medication. These include:
- Hives
- Dizziness
- Fast or pounding heartbeats
- Wheezing
- Difficult breathing
- Swelling of your face, lips, tongue, or throat.
It is important that you let us know which prescription,
over-the-counter medicines and recreational drugs you are currently taking. You
must also tell us about any other medical conditions that you currently have
(or had in the past). This will help us ensure the prescribed medication is
safe and appropriate for you to take.
For full information on warnings, medication interactions and
contraindications, refer to the Patient Information Leaflet. Please read all
packaging and the Patient Information Leaflet before taking any new medicine
and inform our clinical team or your GP of medicines you are taking or intend
to take.
