Cyclizine: nausea, vertigo and travel sickness tablets

Cyclizine treats feeling sick and being sick, and it helps dizziness and vertigo. The NHS lists sickness when travelling, Meniere's disease, side effects of radiotherapy and morning sickness in pregnancy among the causes it can be used for.

It usually comes as tablets that you swallow with water, which can be bought from pharmacies or prescribed. The NHS page does not list brand names or a time to onset.

The NHS does not give a fixed dose; your pharmacist or doctor will tell you how much to take and for how long, and the pack leaflet gives the details for the product you have.

If you miss a dose, skip it and take the next at the usual time. Taking an extra dose can be dangerous, so call NHS 111 if you take more than prescribed.

Because the tablets can be bought from a pharmacy as well as prescribed, it is worth reading the leaflet in your pack every time and asking the pharmacist if anything in it does not fit your situation. Tell them about long-term conditions and every other medicine you use, since cyclizine has more interactions than many people expect.

Cyclizine treats the symptom rather than the cause. If sickness or dizziness keeps coming back, lasts for days, or comes with severe headache, confusion, repeated vomiting or an inability to keep fluids down, that calls for medical assessment rather than longer self-treatment.

Most adults and children aged 6 and over can take cyclizine. It is not suitable if you have high blood pressure, glaucoma, epilepsy, liver problems or heart failure, conditions that affect urination such as an enlarged prostate, or a bowel obstruction, or if you have previously reacted to it. Tell the prescriber or pharmacist about these before starting.

Common effects include constipation or diarrhoea, dry mouth, headaches, blurred vision and drowsiness. Do not drive or use machinery if you have blurred vision or feel drowsy.

Rare serious effects are anaphylaxis (swollen throat or tongue, raised itchy rash, breathing difficulty), muscle twitches, spasms or seizures, heart rhythm problems or palpitations, unusual bleeding and jaundice. Call 999 for anaphylaxis and NHS 111 for other serious effects.

Suspected side effects can be reported through the Yellow Card scheme.

The NHS says not to drink alcohol while taking cyclizine, because it can make you very drowsy and could cause breathing problems.

Medicines that should not be taken with it include the antidepressant amitriptyline, the bladder medicines oxybutynin and solifenacin, sleep aids such as diphenhydramine and zolpidem, the muscle relaxant baclofen, strong painkillers such as codeine and morphine, and anxiety medicines such as diazepam. Ask a pharmacist to check your own list.

Cyclizine can be used in pregnancy, with doctors prescribing the lowest effective dose. It is not usually used while breastfeeding because it could cause side effects in a baby, though a doctor may recommend it for a short time if the benefits outweigh the risks.

You can eat as normal while taking cyclizine. Avoid driving while drowsy or if your vision is blurred.

Domperidone and metoclopramide are other prescription anti-sickness options, and their guides explain how they differ. For vertigo, the cause matters more than the symptom, so persistent dizziness is worth discussing with a doctor.