Zaditen

Zaditen contains ketotifen, an antihistamine and mast cell stabiliser used to prevent and treat allergic conditions including allergic conjunctivitis, allergic rhinitis, and as an adjunct in the management of allergic asthma.

Ketotifen works by blocking histamine H1 receptors and inhibiting the release of inflammatory mediators from mast cells.

Unlike many antihistamines that only block histamine after it has been released, ketotifen has the additional property of stabilising mast cell membranes.

This dual mechanism provides both immediate symptom relief and a preventive effect when used regularly over several weeks.

Zaditen is available as tablets, syrup, and eye drops. The oral forms are used for systemic allergic conditions, while the eye drops are used specifically for allergic conjunctivitis.

Oral ketotifen requires several weeks of regular use to achieve its full prophylactic effect, so patients should not expect immediate results when starting treatment.

For oral forms, take tablets or syrup twice daily with food — once in the morning and once in the evening.

The sedative effect is most pronounced during the first few days of treatment and usually diminishes with continued use. For eye drops, instil one drop into each affected eye twice daily.

Continue treatment regularly even if you feel well, as the prophylactic effect builds over several weeks. Do not stop abruptly if you have been taking oral ketotifen for prolonged periods.

Adults and children over 3 years: 1 mg twice daily with food. May be increased to 2 mg twice daily if needed. Children 6 months to 3 years: 0.5 mg twice daily.

Eye drops: one drop in each affected eye twice daily. Allow at least 4-6 weeks of continuous oral treatment to assess full prophylactic benefit.

Common (affecting more than 1 in 10): drowsiness, particularly during the first few days of treatment.

Common (1 in 10 to 1 in 100): dry mouth, dizziness, and increased appetite with potential weight gain. Uncommon (1 in 100 to 1 in 1,000): headache, nausea, and irritability.

Rare (less than 1 in 1,000): skin rash, cystitis, and hepatitis. The sedative effect typically reduces after the first week of treatment.

Weight gain can be significant in some patients and should be monitored. Eye drops may cause mild transient stinging on application.

Oral ketotifen causes drowsiness — avoid driving or operating machinery until you know how it affects you, especially during the first few days.

Alcohol enhances the sedative effect and should be avoided. Monitor weight during treatment as appetite stimulation can lead to significant weight gain.

Do not use as a rescue treatment for acute asthma attacks — it is a preventive medication only. Diabetic patients should note that the syrup formulation contains sugar.

Known allergy to ketotifen or any excipient. Oral ketotifen should not be used during pregnancy or breastfeeding unless the potential benefit outweighs the risk.

Caution in patients with epilepsy, as ketotifen may lower the seizure threshold. Not suitable as monotherapy for asthma — always use alongside regular preventer inhalers.