Serc

Serc is a tablet for rotational vertigo. Its active ingredient is betahistine dihydrochloride, an anti-vertigo medicine (ATC code N07CA01). The product information says the mechanism is only partly understood. It may act on the histamine system and increase blood flow in the inner ear.

The 16 mg and 24 mg on the box are the weight of the dihydrochloride salt per tablet: 16 mg is equivalent to 10.42 mg of the active base and 24 mg to 15.63 mg. Both strengths hold the same ingredient, so do not take them together on your own.

On this page Serc is sold as 16 mg in a box of 60 tablets (3 strips of 20) and 24 mg in a box of 20 tablets (1 strip).

The Serc 16 mg product information lists vertigo, tinnitus and hearing loss associated with Ménière's syndrome. The 24 mg product information describes Ménière's disease by three main symptoms: vertigo with nausea and vomiting, progressive hearing loss and tinnitus. It also lists symptomatic treatment of vestibular vertigo.

The box sold in Thailand says Serc relieves rotational vertigo and dizziness from vestibular causes, including Ménière's syndrome, often called inner-ear fluid imbalance in Thai.

Many people ask which medicine to take for spinning vertigo. It depends on the cause, so if you have never had a diagnosis, see a doctor first. This medicine does not treat every cause of dizziness.

Doses in the product information for adults, including older adults:

• Serc 16 mg: start with 1 tablet (16 mg) three times daily, preferably with meals. The usual maintenance dose is 24–48 mg per day.
• Serc 24 mg: the recommended starting dose is 24 mg per day, up to a maximum of 48 mg per day (1 tablet morning and evening), adjusted to each person's response.

The pharmacist's view: for the same 48 mg per day, 16 mg means 3 tablets at 3 times and 24 mg means 2 tablets at 2 times, so fewer tablets and doses. Your doctor or pharmacist should still set the strength.

Swallow with water, preferably with or after a meal, which can ease mild stomach upset. If you take it three times a day, the NHS advises leaving 6 to 8 hours between doses.

Common side effects (1 in 100 to 1 in 10 people) in the product information are nausea, indigestion and headache. The NHS says they are usually mild and do not last long.

Side effects with an unknown frequency include:

• mild stomach complaints such as vomiting, stomach pain and bloating, often eased by taking the dose with food or by a lower dose
• skin allergy reactions such as rash, itching, hives and swelling of the face, lips or tongue
• severe allergic reaction (anaphylaxis), which is uncommon

If you have a swollen throat or tongue, a raised itchy rash or difficulty breathing, stop the medicine and get medical help at once (call 1669 in Thailand). For other bothersome side effects, speak to a pharmacist or doctor.

• Do not use: if you are allergic to the active ingredient or any other ingredient, or if you have a phaeochromocytoma.
• Asthma: some people with bronchial asthma do not tolerate it, so they need careful monitoring.
• History of stomach ulcer: caution is advised during treatment.
• Low blood pressure: the NHS says it may not be suitable.
• Previous allergic reaction or serious side effect from it: do not restart it on your own.

Before starting, tell your doctor or pharmacist about your health conditions, current medicines and any allergy history. For sudden severe dizziness with other symptoms, see a doctor rather than self-treating.

Comparing with the betahistine tablets sold here:

• Merislon (Betahistine Mesilate 6 mg) — 6 mg per tablet, box of 30, listed at 1-2 tablets three times daily. Choose it when your doctor or pharmacist advises it.
• Mertigo (Betahistine Mesilate 6 mg / 12 mg) — also the mesilate salt, in two strengths. Choose it when your doctor or pharmacist advises it.
• Serc (Betahistine Dihydrochloride 16 mg / 24 mg) — the dihydrochloride salt with a higher mg figure per tablet. Choose it when your doctor or pharmacist advises it.

A pharmacist's caution: mesilate and dihydrochloride are different salts, and the mg on each label is the weight of that salt. Do not compare Serc's mg one-for-one with Merislon or Mertigo, and do not swap without asking a pharmacist.

In short: same kind of active ingredient, different salts. Stay on what your doctor set; for a higher strength per tablet, ask a pharmacist about Serc.

The product information says no interaction studies have been done in people, but it points to two groups to be careful with:

• MAO inhibitors, including MAO-B selective ones such as selegiline used in Parkinson's disease: laboratory data suggest they may inhibit the breakdown of the active ingredient in the body, so use them together with caution.
• Antihistamines: because the active ingredient is an analogue of histamine, the two groups could in theory reduce each other's effect.

If you take regular medicines, herbal products or supplements, tell your pharmacist or doctor before starting so the full list can be checked together.

This is not a medicine to expect results from after the first tablet. The 24 mg product information says improvement may be seen after several weeks of treatment, and the best results are sometimes seen only after several months. The NHS says you may need to take it for some time before your symptoms improve.

In the early period, take it on time as your doctor or pharmacist directs and keep track of your symptoms. Do not raise the dose on your own because it feels slow. If you are not better, or you get worse, go back to your doctor or pharmacist to reassess.

Where Can I Buy Serc?

Order online at Intimo Life with delivery across Thailand in 1-3 working days. Parcels are packed discreetly for your privacy, with no product name on the outside of the box.