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.
Side effects of cyproterone acetate
The side effects of cyproterone acetate (CPA), a steroidal antiandrogen and progestin, including its frequent and rare side effects, have been studied and characterized. It is generally well-tolerated and has a mild side-effect profile, regardless of dosage, when it used as a progestin or antiandrogen in combination with an estrogen such as ethinylestradiol or estradiol valerate in women. Side effects of CPA include hypogonadism and associated symptoms such as demasculinization, sexual dysfunction, infertility, and osteoporosis; breast changes such as breast tenderness, enlargement, and gynecomastia; emotional changes such as fatigue and depression; and other side effects such as vitamin B12 deficiency, weak glucocorticoid effects, and elevated liver enzymes. Weight gain can occur with CPA when it is used at high doses. Some of the side effects of CPA can be improved or fully prevented if it is combined with an estrogen to prevent estrogen deficiency. Little quantitative data are available on many of the potential side effects of CPA.