alniditan

Alniditan (, ; developmental code name R-91274) is a selective serotonin 5-HT1B and 5-HT1D receptor agonist with migraine-preventive effects which was never marketed. It was under development for treatment of migraine via subcutaneous injection in the 1990s and reached phase 3 clinical trials for this indication prior to the discontinuation of its development.

==Pharmacology== ===Pharmacodynamics=== {| class="wikitable floatleft" style="font-size:small;" |+ |- ! Target !! Affinity (Ki, nM) |- | 5-HT1A || 0.48–4.0 (Ki)51–116 ()79–~100% () |- | 5-HT1B || 0.39–2.5 (Ki)1.0–17 ()81% () |- | 5-HT1D || 0.4–2.5 (Ki)1.1–6.3 ()~100% () |- | 5-HT1E || 240–525 (Ki)2,090–6,170 () |- | 5-HT1F || 360–1,230 (Ki)1,200–6,760 () |- | 5-HT2A || 3,720 (Ki) or >10,000 () |- | 5-HT2B || 132 (Ki)71 () |- | 5-HT2C || 2,930 (Ki) (pig) () |- | 5-HT3 || (mouse) |- | 5-HT4 || 5,120 (guinea pig) |- | 5-HT5A || |- | 5-HT6 || 5,470 (rat) |- | 5-HT7 || 55 (Ki)479 () |- | α1 || 97 (rat) |- | α1A–α1D || |- | α1 || 460 (rat) |- | α2A || 37 |- | α2B || 170 |- | α2B || 18 |- | β1, β2 || |- | β3 || |- | D1 || (rat) |- | D2 || 1,950 |- | D3 || 280 |- | D4 || 80 |- | D5 || |- | H1 || 3,830 (guinea pig) |- | H2–H4 || |- | mACh || (rat) |- | M1–M5 || |- | I1, I2 || |- | σ1 || 40 (guinea pig) |- | σ2 || |- | || |- | || |- | || (rat) |- | || (rat) |- | || 365 (rat) |- class="sortbottom" | colspan="2" style="width: 1px; background-color:var(--background-color-notice-subtle,#eaecf0); color:inherit; text-align: center;" | Notes: The smaller the value, the more avidly the drug binds to the site. All proteins are human unless otherwise specified. Refs: |}