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Zovirax (Aciclovir)

Zovirax (Aciclovir)

Zovirax belongs to the group of medicines called antivirals, which attack viruses in the body to prevent them from growing and spreading, although they do not eradicate them completely. Zovirax acyclovir tablets contain the active ingredient acyclovir, as well as microcrystalline cellulose, aluminium, magnesium silicate, sodium starch glycolate, povidone K30, magnesium stearate, hypromellose, polyethylene glycol 400, titanium dioxide (E171) and polyethylene glycol 8000. Zovirax is also available in different forms to treat different conditions.

The herpes virus is the cause of several different health issues in its various forms, from the herpes simplex virus which causes cold sores and genital herpes to the varicella-zoster virus which causes chickenpox and shingles. While you can purchase over-the-counter remedies to treat cold sores, sometimes this treatment is simply not strong enough to combat the virus and get rid of the symptoms, and it is unlikely to be strong enough to treat the other illnesses caused by the virus.

 

Indeed, the herpes virus can lay dormant in the body and reappear at any moment, so when tackling illnesses caused by the herpes virus, an antiviral medicine is usually required.

 

What is Zovirax acyclovir?

Zovirax belongs to the group of medicines called antivirals, which attack viruses in the body to prevent them from growing and spreading, although they do not eradicate them completely. Zovirax acyclovir tablets contain the active ingredient acyclovir, as well as microcrystalline cellulose, aluminium, magnesium silicate, sodium starch glycolate, povidone K30, magnesium stearate, hypromellose, polyethylene glycol 400, titanium dioxide (E171) and polyethylene glycol 8000. Zovirax is also available in different forms to treat different conditions. The mildest version is a topical cream or ointment, while the stronger medication is available as a dispersible tablet or as a liquid suspension, which is used when local topical treatments are ineffective or simply unsuitable for treating the virus.

 

When is Zovirax acyclovir used?

Zovirax acyclovir is used to treat two common viruses: the herpes simplex virus and the varicella-zoster virus. It works by attacking the virus to prevent it from multiplying, which in turn lessens the severity of the virus to stop it from spreading further. It is used to treat the following common illnesses:

  • Chickenpox;
  • Shingles;
  • Cold sores;
  • Genital herpes;
  • Hepatic whitlow.

 

Zovirax can be used by both adults and children.

 

How do you use Zovirax acyclovir?

You should always use medicines exactly as your doctor or pharmacist has instructed you to.

 

Zovirax can come as a topical cream or ointment or as a dispersible tablet. The tablet form is used to treat more severe cases and to treat chickenpox and shingles. Zovirax acyclovir can also be given via intravenous drip in a hospital setting if required.

 

When taking Zovirax in tablet form at home:

  1. Start taking your medicine as soon as possible once it has been prescribed;
  2. Dissolve the tablet in a glass of water and stir it, then drink it;
  3. You can also swallow the tablet whole with a little water. Always drink plenty of water when taking Zovirax tablets as they can cause kidney problems if you do not.

 

To apply the cream:

  1. Wash your hands.
  2. Apply to the affected area.
  3. Wash hands again.
  4. Repeat every four hours.

 

What dosages are there?

The dose you are given will depend on the severity of your virus, your age and your weight. As such, the details below are given as a general guide only and you should always take the dose that your doctor prescribes. Zovirax tablets come in 200 mg, 400 mg and 800 mg versions. The usual dose for adults is 200 mg – 800 mg taken five times a day. You should space the dose so that you take one tablet roughly every four hours: a suggested guide for timings is: 7 am, 11 am, 3 pm, 7 pm and 11 pm. The treatment should be taken for seven consecutive days. You should always complete the course of treatment given to you, even if you feel better before the treatment finishes, to prevent the virus from spreading again.

 

Never take more than your prescribed dose. If you miss a dose, take it as soon as you remember unless it is nearly time for your next Zovirax tablet, in which case you should skip the forgotten dose. Never take a double dose to make up for a missed Zovirax tablet. Try setting an alarm as a reminder for you to take your medication at the right time. If you take too much Zovirax acyclovir you may experience the following:

  • Hallucinations;
  • Feeling confused or agitated;
  • Fits;
  • Loss of consciousness.

 

You should stop taking the medication and seek immediate medical assistance.

 

Zovirax cream contains 5% acyclovir and comes in 2 mg or 10 mg tubes, it should be applied to the affected area every four hours.

 

What are the side effects of Zovirax acyclovir?

As with all medication, Zovirax comes with a warning of some side effects, although of course not everyone who takes Zovirax tablets or uses Zovirax cream will suffer from them. If side effects become serious or unbearable speak to your doctor. Zovirax comes with a risk of allergic reactions. If you experience an allergic reaction, stop taking the medicine and seek immediate medical assistance.

 

The following are signs of an allergic reaction:

  • Swelling around the face, lips or tongue;
  • Rash, itching or hives on your skin;
  • Difficulty breathing, shortness of breath or wheezing;
  • Unexplained high temperature.

 

Common side effects that may affect up to 1 in 10 people include:

  • Dizziness;
  • Nausea;
  • Diarrhoea;
  • Stomach pain;
  • Headaches;
  • Itching;
  • Skin reactions after exposure to light;
  • Tiredness;
  • Fever.

 

Uncommon side effects that may affect up to 1 in 100 people include:

  • A bumpy, itchy rash like hives;
  • Hair loss;
  • Reduced numbers of red blood cells (anaemia);
  • Reduced numbers of white blood cells (leukopenia);
  • Reduced numbers of blood platelets – cells that help the blood to clot (thrombocytopenia).

 

There are some simple things you can do try to help with the side effects, such as drinking plenty of water, eating a simple diet and getting enough rest to allow your body to recover. You can also use unscented cream to help with itching and flaking skin.

 

Very rare side effects that may affect up to 1 in 10,000 people include:

  • Shaking or tremors;
  • Hallucinations;
  • Nosebleeds;
  • Bruising easily;
  • Feeling agitated or confused;
  • Inability to think clearly or concentrate;
  • Inflammation of the liver (hepatitis);
  • Yellowing of the skin or whites of the eyes;
  • Kidney problems (passing little or no urine);
  • Decreased energy, weakness, shortness of breath, light-headedness, palpitations, anaemia;
  • Effects on some blood urine tests;
  • Unsteadiness and lack of coordination;
  • Difficulty speaking or hoarseness;
  • Seizures;
  • Pain in the lower back, around the kidneys or just above the hip;
  • Unconsciousness;
  • Paralysis of all or part of the body.

 

When should you not use Zovirax acyclovir?

Do not use Zovirax tablets or Zovirax cream if you are allergic to acyclovir, valaciclovir or any of the other ingredients listed on the packet. You should also check with your doctor or pharmacist before taking Zovirax if you:

  • Are over the age of 65;
  • Have a weak immune system;
  • Have kidney problems;
  • Are thirsty. When taking Zovirax tablets or Zovirax cream, you must ensure you are drinking plenty of liquids (water).

 

Take care when driving or operating heavy machinery while using Zovirax tablets or Zovirax cream, as you may experience dizziness, tiredness and an inability to concentrate. If you do experience these side effects, do not drive or operate heavy machinery until you are sure they have disappeared. Check with your doctor or pharmacist if you are pregnant or breastfeeding as it may not be suitable for you to take Zovirax at this time.

 

Does Zovirax acyclovir interact with other medications?

As with all medication, there is a risk that different medications can interact with one another and lessen the effectiveness or cause further problems. Always discuss any medication you are taking with your pharmacist or doctor, including herbal medicines and supplements. In particular, tell your doctor or pharmacist if you are taking any of the following medications:

  • Cimetidine, which is used to treat stomach ulcers;
  • Probenecid, which is used to treat gout;
  • Tacrolimus, ciclosporin or mycophenolate mofetil, which are used to prevent your body from rejecting transplanted organs;
  • Aminophylline or theophylline, which are used to treat asthma.

 

Where can you buy Zovirax acyclovir?

You can buy Zovirax acyclovir from any pharmacy, wherever is most convenient for you. You can purchase it online and have it delivered to your home, office or local pharmacy, or you can buy it directly from your local pharmacy.

 

Can I get Zovirax acyclovir without a prescription?

You can only buy Zovirax acyclovir in tablet or liquid form with a prescription from a doctor. You will need to consult a doctor to check that the medication is suitable and the best option for you.

 

Topical Zovirax cream to treat oral cold sores can be purchased from a pharmacy without a prescription.

 

Sources:

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GlaxoSmithKline (2015). Zovirax IV 250mg – Patient Information Leaflet (PIL) – (emc). [online] Medicines.org.uk. Available at: https://www.medicines.org.uk/emc/product/5472/pil [accessed 5 Jan 2020].

 

Herpes Viruses Association (2020). About herpes simplex virus – Herpes Viruses Association. [online] Herpes Viruses Association. Available at: https://herpes.org.uk/frequently-asked-questions/herpes-simplex-virus/ [accessed 3 Jan 2020]. NHS UK (2019).

 

Aciclovir: a medicine used to treat cold sores, herpes and other viral infections. [online] nhs.uk. Available at: https://www.nhs.uk/medicines/aciclovir/ [accessed 6 Jan 2020].

 

Sinha, S. (2019). Zovirax (acyclovir) Uses, Dosage, Side Effects – Drugs.com. [online] Drugs.com. Available at: https://www.drugs.com/zovirax.html [accessed 3 Jan 2020].