Table 1. Stems of SCEs Used at Least 10 Times in the Last 20 Years.

ranking of stems in SCEs	stem	definition	example
#1a	-ine	alkaloids and organic bases	atropine (according to WHO, ∼17.5% of INNs have used this stem in lists p1-p119)9
#2b	-tinib	tyrosine kinase inhibitors	imatinib
#3b	-stat–/–stat	enzyme inhibitors	atorvastatin, cobicistat
#3b	vir–/–vir–/–vir	antivirals (undefined group)	maraviroc, remdesivir
#5b	gli–/–gli-	antihyperglycaemics	glibenclamide, dapagliflozin
#5a	-one	ketones	naloxone (according to WHO, ∼7.5% of INNs have used this stem in lists p1-p105)9
#7b	-imod	immunomodulators, both stimulant/suppressive and stimulant	fingolimod
#8	-sertib	serine/threonine kinase inhibitors	no drug is yet on the market
#9c	fos–/–fos-	phosphorus derivatives; various pharmacological categories belonging to “fos”, other than insecticides, anthelminthics, pesticides, etc.	foscarnet, sofosbuvir
#10	-lisib	phosphatidylinositol 3-kinase inhibitors, antineoplastics	idelalisib
#11b	-ast	antiallergic or anti-inflammatory, not acting as antihistaminics	zafirlukast
#11b	-tant	neurokinin (tachykinin) receptor antagonists	aprepitant
#13	-anib	angiogenesis inhibitors	nintedanib
#13	-bulin	antineoplastics; mitotic inhibitors, tubulin binders	eribulin
#13	-ciclib	cyclin dependent kinase inhibitors	palbociclib
#16b	-abine	arabinofuranosyl derivatives; nucleosides antiviral or antineoplastic agents, cytarabine or azacitidine derivatives	capecitabine
#17	-entan	endothelin receptor antagonists	bosentan
#17	-oxacin	antibacterials, nalidixic acid derivatives	levofloxacin
#19	-conazole	systemic antifungal agents, miconazole derivatives	ketoconazole
#19b	prost–/–prost–/–prost	prostaglandins	prostalene (veterinary use), misoprostol, latanoprost
#21	-caftor	cystic fibrosis transmembrane regulator (CFTR) protein modulators, correctors, and amplifiers	ivacaftor
#21	-nicline	nicotinic acetylcholine receptor partial agonists/agonists	varenicline
#23	-tecan	antineoplastics, topoisomerase I inhibitors	irinotecan
#23	-adol–/–adol	analgesics	tramadol
#23	-ciguat	guanylate cyclase activators and stimulators	riociguat
#23	-denoson	adenosine A receptor agonists	regadenoson
#27	-parib	poly-ADP-Ribose polymerase inhibitors	olaparib
#27	-terol	bronchodilators, phenethylamine derivatives	formoterol
#27	-vaptan	vasopressin receptor antagonists	tolvaptan

^aA number of other stems include this one (e.g., -terone for androgens).

^bThese stems possess substems that categorize in more detail. For example, -brutinib, -citinib, -ertinib, and -metinib group together tyrosine kinase inhibitors (-tinib) with the same target (Bruton kinase, Janus Kinase, EGFR, MAPK, respectively).

^cThe stem -fos is, instead, used for insecticides, anthelmintics, pesticides, etc., phosphorus derivatives.