Can you drink alcohol on Claritin?
An occasional drink is usually low-risk with Claritin (loratadine), but the NHS advises against alcohol because both can leave you feeling sleepy — and that combined drowsiness is the thing to watch.
Why
Loratadine is a second-generation, "non-drowsy" antihistamine, which is why MedlinePlus lists no specific alcohol warning and flags drowsiness only as a possible side effect to report if severe. That makes the interaction much milder than with older sedating antihistamines (e.g. diphenhydramine). But it is not zero: the NHS notes loratadine "is classed as a non-drowsy antihistamine but it's still possible to feel sleepy after taking it," and advises "It's best not to drink alcohol while you're taking loratadine, as it can make you feel sleepy." Both alcohol and any residual sedation from the drug act on the central nervous system, so their drowsiness can add up in some people.
What to watch for
See how loratadine alone affects you before adding alcohol — a minority of people do feel sleepy on it. If you feel drowsy, don't drive or operate machinery. Heavier drinking amplifies the effect. If you're pregnant or breastfeeding, have liver disease, or take other medicines that cause drowsiness (sedatives, sleep aids, other antihistamines, some pain meds), ask a pharmacist before combining. Note some "Claritin" combo products (e.g. Claritin-D) add a decongestant, pseudoephedrine — a different profile — so check the Drug Facts label on your exact product.
This is general reference, not medical advice, and not a guarantee of safety. Interactions depend on your doses, health conditions, and other medicines. Always confirm with your pharmacist or doctor before combining products, and follow the dosing on each label.