Pharmacology - Antihistamines (Practice)

Questions regarding antihistamines generally want you to know what H1 and H2 antihistamines are used for:
H1 antihistamines are useful for:
1. Treating dermatologic manifestations of an allergic response. (ex. chlorpheniramine)
2. Preoperative medication for sedation, antiemetic properties, anticholinergic effects. (ex. promethazine)
3. For controlling the symptoms of parkinsonism (ex. diphenhydramine)

H2 antihistamines such as cimetidine are used to reduce gastric acid secretion (ex. cimetidine). Now available OTC for heartburn