Cinnarizine (Stugeron): uses, drowsiness and cautions

Cinnarizine reduces the sensations of vertigo, where you or your surroundings feel as if they are spinning, and the nausea and vomiting that come with it. The NHS lists travel sickness, seasickness and Ménière's disease, an inner ear condition that affects balance and hearing. The Stugeron 15mg product information is narrower, licensing it for the control of motion sickness. You can buy it from a pharmacy or be prescribed it.

Tablets are swallowed, and some types can be sucked or chewed; it is best taken after eating. For travel sickness the NHS says adults and children aged 12 and over take 2 tablets of 15mg 2 hours before travelling, then 1 tablet every 8 hours during the journey if needed. Children aged 5 to 11 take 1 tablet 2 hours before and half a tablet every 8 hours if needed. If a doctor prescribes it, follow their directions, because dose and duration depend on the reason.

If you are using it for travel sickness and miss a dose, you can take another if at least 8 hours have passed since the last one. For Ménière's disease, skip a missed dose and take the next at the usual time. Never double up. Taking an extra dose is unlikely to cause problems, but speak to a pharmacist as soon as possible if you take more than the packet or prescription says, or call 111 if you cannot, or if it was deliberate.

The commonest side effect is feeling very sleepy. The Stugeron product information found somnolence in 9.9% of people in pooled trials, especially at the start of treatment, and weight increase in 1.5%. If you feel drowsy, do not drive, cycle or use machinery until it passes. Alcohol, sedatives and tricyclic antidepressants can increase the sedative effect, and the NHS advises avoiding alcohol.

Taking it with food lowers the chance of indigestion; the product information notes that, as with other antihistamines, it may cause stomach discomfort. Because of its antihistamine effect, it may prevent a positive skin allergy test reaction if used within 4 days beforehand.

Other common effects listed by the NHS are heartburn, bloating, nausea and weight gain. Serious effects are rare but need prompt action: an allergic reaction with a swollen throat or tongue, a raised itchy rash or difficulty breathing; liver problems with itchy skin, dark urine and yellowing of the skin or eyes; low, twitchy or jerky movements, muscle stiffness, trembling or shaking, which is more likely in older people who have taken cinnarizine for a long time; and a red, raised, sometimes ring-shaped rash on sun-exposed skin.

Call 999 for suspected anaphylaxis and 111 for any other serious effect. Speak to a pharmacist or doctor if side effects bother you or do not go away. Suspected side effects can be reported through the Yellow Card scheme.

Most adults and children aged 5 and over can take cinnarizine. The NHS lists reasons it may not suit you: a previous allergic reaction or serious side effect, liver or kidney problems, prostate problems or difficulty passing urine, glaucoma or a risk of it, epilepsy, Parkinson's disease and porphyria. The product information adds that in Parkinson's disease it should only be given if the advantages outweigh the risk of worsening the disease, and that it should be avoided in porphyria.

Tablets contain lactose and sucrose, so people with rare hereditary problems with fructose or galactose, or lactase deficiency, glucose-galactose malabsorption or sucrase-isomaltase insufficiency, should not take them. Check the leaflet for your product.

The NHS says some types of medicine may not mix well with cinnarizine: strong painkillers such as tramadol, medicines for migraine and nerve pain such as amitriptyline, sleeping pills such as zopclone, and anxiety medicines such as diazepam, mostly because they add to sleepiness. Tell your doctor about all medicines, herbal remedies and supplements.

Cinnarizine is not usually recommended in pregnancy; talk to a doctor or pharmacist, who may suggest another medicine. The Stugeron entry says its safety in human pregnancy has not been established and that it is not advisable. It is not usually used while breastfeeding and the product information says its use is not recommended in nursing mothers because there are no data on whether it reaches breast milk.