oral+antihistamines+sedating

=Oral antihistamines (Sedating)=

How it works
Blocks the action of histamine, reducing the effects you see in hayfever. (also has some drying effects) //Antagonise the action of histamine at H1 receptors, reducing histamine-related vasodilation and increased capillary permeability. They also have anticholinergic activity, some have alpha-blocking activity and some have antiserotonin activity, eg cyproheptadine.//

Questions to Ask
What medications? - medical conditions? //contraindications to anticholinergics (////Closed angle glaucoma, increased intraocular pressure,// //bladder neck obstruction)// - allergies? //Avoid phenothiazine antihistamines in children <2–3 years. Promethazine is category C, safe to use in early pregnancy, but theoretical risk of neurological disturbance in infants when taken in late pregnancy//

How to take
//Controlled release tablet//, 6mg (one tablet) twice daily. Swallow tablet whole; do not crush or chew it. //Conventional tablet//, 2mg (one tablet) 4 times daily. Initially 22.65mg (half a 45.3mg tablet) 2–3 times daily; up to 45.3mg 3 times daily. Oral 25–75 mg once daily, or 10–25 mg 2–3 times daily
 * Dexchlorpheniramine**: Adult, child >12yrs
 * Pheniramine:** Adult, child >10yrs
 * Promethazine Hydrochloride:** Adult

Side effects
Common: sedation, dizziness, tinnitus, blurred vision, euphoria, incoordination, anxiety, insomnia, tremor, nausea, vomiting, constipation, diarrhoea, epigastric discomfort, dry mouth, cough

Other advice?
- Avoid alcohol when taking this medication as it can increase drowsiness - Sedating antihistamines are limited by their sedating and anticholinergic effects (phenothiazines such as promethazine have the most potent anticholinergic effects and are significantly sedative)

CMI
Dexchlorpheniramine: [|AMH] Polaramine Pheniramine: [|AMH] Avil Promethazine Hydrochloride: [|AMH] [|Phenergan]