Antihistamine
The vast majority of marketed H-antihistamines are receptor antagonists and only a minority of marketed compounds are inverse agonists at the receptor. Clinically, H-antihistamines are used to treat allergic reactions and mast cell-related disorders. Sedation is a common side effect of H-antihistamines that readily cross the blood–brain barrier; some of these drugs, such as diphenhydramine and doxylamine, are therefore used to treat insomnia. H-antihistamines can also reduce inflammation, since the expression of NF-κB, the transcription factor the regulates inflammatory processes, is promoted by both the receptor's constitutive activity and agonist (i.e., histamine) binding at the H receptor.
Norgestimate
Side effects associated with the combination of estradiol and norgestimate in postmenopausal women, with greater than or equal to 5% incidence over one year, include headache (23%), upper respiratory tract infection (21%), breast pain (16%), back pain (12%), abdominal pain (12%), flu-like symptoms (11%), arthralgia (9%), vaginal bleeding (9%), dysmenorrhea (8%), sinusitis (8%), vaginitis (7%), pharyngitis (7%), fatigue (6%), pain (6%), nausea (6%), viral infection (6%), flatulence (5%), tooth disorder (5%), myalgia (5%), dizziness (5%), depression (5%), and coughing (5%).