- H1 first generation antihistamines

- inverse agonists that bind preferentially to the inactive conformation of the H1 receptor and shift the equilibrium toward the inactive receptor state

- allergic rhinitis, anaphylaxis, insomnia, motion sickness

- first one is benadryl

- neutral at physiologic pH and cross the BBB

Ethylenediamines: Pyrilamine

Tripelennamine

Alkylamine: Chlorpheniramine + Brompheniramine

Piperidines: Cyproheptadine + Phenindamine

- All very similar to diphenhydramine (Benadryl)

- Can't take with MAOIs

- First generation H1-antihistamines

- First generation H1-anthistamine

- similar action of Benadryl

- used to primarily relieve pre-op anxiety and reduce post-op nausea and vomiting

- First generation H1-antihistamines

- Pruitus (itchiness), alcohol withdrawl, anxiety, vomiting (first one), Motion sickness (last two)

- First generation H1 antihistamine

- anxiety, depression, pruritus

- mainly used just in patients with depression b/c even small doses can cause disorientation in nondepressed patients

- Second generation H1 antihistamines (less gets into the CNS then first gen therefore less sedating and less dry mouth)

- Allergic rhinitis and Urticaria (hives)

Alkylamines: Acrivastine

Piperidines: Loratadine + Desloratadine + Levocabastine + Ebastine + Mizolastine + Fexofenadine

- Second generation H1 antihistamines (less gets into the CNS then first gen therefore less sedating and less dry mouth)

- Allergic rhinitis and Urticaria (hives)

- Second generation H1 antihistamines (less gets into the CNS then first gen therefore less sedating and less dry mouth)

- Allergic conjunctivitis and rhinitis

- H2 receptor antagonists

- like Prilosec for stomach acid