Shingles Treatment in Hong Kong: Aciclovir, Valaciclovir, Famciclovir

The skin on one side of your chest stings when your shirt moves across it. A few days later a band of blisters has appeared in the same place, stopping short of the middle of your body. Tingling first, then a rash on one side only, is how shingles usually runs.

Hong Kong's Centre for Health Protection uses the medical name herpes zoster, commonly called 「生蛇」, and explains where it comes from. The chickenpox virus stays latent in the nervous system after the childhood illness and can reactivate years later when immunity falls (Hong Kong's Centre for Health Protection). The same page makes the practical point that early antiviral treatment can speed healing of the blisters, reduce symptoms and lower the risk of complications.

Antiviral tablets do most good in the first three days (NHS; CDC). What follows draws on those two sources, the CHP page and the manufacturers' labels for aciclovir, valaciclovir and famciclovir.

In short

• Shingles usually opens with tingling or pain on one side of the body, followed by a rash a few days later.
• Antivirals work best started within 3 days of the rash appearing, so do not wait to see whether it passes.
• Aciclovir, valaciclovir and famciclovir are the three used, and each course runs for about 7 days.
• Paracetamol, a cool compress and loose clothing help the pain; pain that outlasts the rash is post-herpetic neuralgia.
• Rash on the eye or nose, changes to vision, pregnancy, severely weakened immunity, or an age of 17 or under means urgent advice.

What are the first signs of shingles, and why does the 72-hour window matter?

Shingles rarely arrives without warning. Most people first notice tingling or pain in a strip of skin on one side of the body, sometimes with a headache or a general feeling of being unwell (NHS). The rash turns up a few days later. Red blotches become itchy blisters that ooze, then dry and scab over, and the whole area can take up to four weeks to heal. It stays on one side: the NHS says a rash on both the left and right of the body is unlikely to be shingles. Rarely, the pain comes without a rash.

Three days is the number that governs treatment. The NHS asks adults to see a pharmacist within 3 days of the rash appearing, and the CDC says treatment is most effective within 72 hours of symptom onset (NHS; CDC). The reason is in what antivirals do: they speed up the clearing of lesions, hold back new ones, cut viral shedding and reduce the severity of the acute pain, according to the CDC. The valaciclovir label is blunter about the other end of the window. Efficacy in people who started more than 72 hours after the rash appeared has not been established (valaciclovir label).

That is why the advice is not to wait and see. A mild rash may need no treatment at all, and the NHS says antivirals are usually offered when the pain or rash is moderate to severe, when the rash sits outside the chest, tummy and back, or when immunity is weakened. Waiting costs you the days when the tablets work best.

Which antivirals treat shingles, and how are they taken?

Three drugs carry the job, and the CDC lists aciclovir, valaciclovir and famciclovir as the preferred options (CDC). The CDC says these antivirals work best when started early, whichever one is used.

The tablet counts differ because the drugs differ. Aciclovir is taken five times across the day, and the 800 mg tablet makes one dose. Valaciclovir is converted into aciclovir inside the body, so it is taken three times a day and the 1000 mg tablet makes one dose. Famciclovir sits at three doses a day as well, 8 hours apart.

Those doses assume adult kidneys working normally. Both labels adjust for reduced kidney function: aciclovir drops to 800 mg twice daily when creatinine clearance is below 10 mL/min and 800 mg three times daily between 10 and 25 (aciclovir SmPC); the famciclovir gap between doses stretches from every 12 hours at a clearance of 40 to 59 mL/min to 250 mg every 24 hours below 20 (famciclovir label). If you already know your kidney function is reduced, that is the detail to raise before you start.

Drink water through the course. The labels stress hydration, and they name elderly people and people with kidney disease as more likely to run into neurological effects such as agitation, confusion, hallucinations or seizures, usually when the dose is higher than the kidneys can handle. If any of those appear, stop the tablets and get help quickly (valaciclovir label; aciclovir SmPC).

The ordinary side effects are the ones you would guess: headache, nausea, vomiting and diarrhoea. In the valaciclovir shingles trial, nausea affected 15% of people and headache 14%. In the famciclovir trials, headache was reported by 22.7% against 17.8% on placebo, and nausea by 12.5% against 11.6%. Aciclovir can be taken with or without food, and the course is finished even if the rash is settling (MedlinePlus).

How do you ease the pain, and what is post-herpetic neuralgia?

By the time the blisters have scabbed, the burning in that strip of skin can still be keeping you awake. Paracetamol is the first thing to reach for. The NHS also suggests a cool compress several times a day, loose clothing, keeping the rash clean and dry, and avoiding sticky dressings or rough fibres against the skin (NHS). Steroid tablets and nerve-pain medicines can be part of treatment too, and starting antivirals early lowers the chance of longer-lasting problems.

Post-herpetic neuralgia is the name for pain that continues in the area of the rash after the skin has healed (NHS). It can ache, burn or come as sharp pain, and the skin can be so sensitive that light touch or a change in temperature hurts. Some people describe itching, others a patch of numbness. It is often mild. For some it is severe, and it usually improves, taking anywhere from a few months to more than a year.

Treatment for it is different from treatment for the shingles itself. Paracetamol, sometimes with codeine, covers mild to moderate pain. Nerve pain is treated with amitriptyline, duloxetine, gabapentin or pregabalin, and lidocaine plasters can be applied to the sore area. Nerve-pain medicines start at a low dose and build over a few weeks, so they may not work straight away. Loose cotton or silk next to the skin, an ice pack wrapped in a towel for up to 20 minutes every 2 to 3 hours, and cool baths all help in the meantime.

One number from the valaciclovir label is worth knowing if you are older: in the shingles study, post-herpetic neuralgia lasted longer in people aged 65 and over (valaciclovir label). That is an argument for starting treatment early rather than waiting.

When is shingles urgent?

Most people recover from shingles without problems. A short list of situations needs urgent medical advice, and the NHS sets it out plainly: shingles while pregnant; shingles while breastfeeding with a rash on the breast; a rash on the eye or nose; any change to your vision; a severely weakened immune system, from chemotherapy for example; and an age of 17 or under (NHS).

The eye is the reason that list exists. The CDC notes that ophthalmic zoster should be diagnosed and treated within 72 hours to prevent progressive corneal involvement and potential vision loss (CDC). The NHS puts a rash on the nose in the same urgent list as the eye.

Watch for weakness on one side of the face, and for hearing problems or a change in how things sound. Those point to Ramsay Hunt syndrome, where the nerve serving the face is involved. A rash that becomes infected may need antibiotics. Pregnancy with shingles is usually mild and usually carries no risk to mother or baby, but a GP should arrange specialist advice on treatment (NHS). The aciclovir label says it is used in pregnancy only when the benefit outweighs the unknown risks, and notes that a registry of exposed pregnancies showed no increase in birth defects (aciclovir SmPC).

Can you pass shingles on to someone else?

This is the question that worries people with a new blister, especially if there is a newborn or a pregnant friend nearby. You cannot catch shingles from someone who has it (NHS). The virus in the blister fluid is the chickenpox virus, though, and someone who has never had chickenpox or the vaccine can catch chickenpox from that fluid. The CHP makes the same point: chickenpox spreads by contact with fluid from the vesicles of chickenpox or herpes zoster (Hong Kong's Centre for Health Protection).

Two conditions limit the risk. You are only infectious while the rash is oozing, so a rash that has scabbed over is no longer a source. And the fluid has to reach someone who has no protection. Keep the rash covered while it weeps, and stay off work or school during that stage if it cannot be covered (NHS). Keep away from pregnant people who have never had chickenpox, from anyone with weak immunity, and from babies under one month old. The chickenpox page covers the same virus in its first illness.

Does the shingles vaccine matter, and which shingles treatments does PockDose list?

It does, as background. The CDC says the recombinant zoster vaccine Shingrix comes in two doses for adults aged 50 and over, and is over 90% effective at preventing shingles and post-herpetic neuralgia in healthy adults in that age group (CDC). It is also advised after a previous episode, once the rash has gone, and it is put off during pregnancy. NHS eligibility runs from people who turned 65 on or after 1 September 2023, through unvaccinated adults aged 70 to 79, to adults of 18 and over with a severely weakened immune system, and shingles after vaccination tends to be milder (NHS). The CHP advises that older adults and immunocompromised adults may consider the vaccine after consulting doctors (Hong Kong's Centre for Health Protection). PockDose does not list the vaccine; the listings here are the antiviral tablets that treat an episode.

Match the strength to the dose in the table above: 800 mg aciclovir five times a day, 1000 mg valaciclovir three times a day where one tablet is one dose, or 500 mg famciclovir every 8 hours. Strengths and pack sizes sit on each product page, and the shingles page and the antivirals category gather the range; there are longer pages on aciclovir, valaciclovir and famciclovir. Ordering from PockDose needs no prescription. Start the course as soon as the rash appears, because the first three days are the ones that do the work.