– pyridazines – cilazapril – luminol – maleic hydrazide – phthalazines – hydralazine – dihydralazine – todralazine – pyridines – aminopyridines – 4-aminopyridine – amrinone – milrinone – methapyrilene – phenazopyridine – pyrilamine – tripelennamine – betahistine – carbolines – clopidol – dihydropyridines – amlodipine – dicarbethoxydihydrocollidine – felodipine – isradipine – nicardipine – nifedipine – nimodipine – nisoldipine – nitrendipine – 3-pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, methyl ester – dimethindene – 2,2'-dipyridyl – disopyramide – doxylamine – indinavir – isonicotinic acids – ethionamide – iproniazid – isoniazid – nialamide – prothionamide – pyridoxic acid – 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine – metyrapone – naphthylvinylpyridine – nevirapine – nicotine – nicotinic acids – arecoline – clonixin – etazolate – niacin – niacinamide – 6-aminonicotinamide – nicorandil – nikethamide – niceritrol – niflumic acid – nimodipine – pipemidic acid – piromidic acid – 3-pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, methyl ester – xanthinol niacinate – nicotinyl alcohol – omeprazole – pheniramine – brompheniramine – zimeldine – chlorpheniramine – picolines – amprolium – vitamin b 6 – pyridoxal – pyridoxal phosphate – pyridoxamine – pyridoxine – picolinic acids – fusaric acid – picloram – pyridoxic acid – streptonigrin – polyvinylpyridine n-oxide – pyridinium compounds – cetylpyridinium – desmosine – diquat – isodesmosine – 1-methyl-4-phenylpyridinium – obidoxime chloride – paraquat – pyridostigmine bromide – pyrithiamine – trimedoxime – viologens – benzyl viologen – pyridones – bemegride – iodopyridones – iodopyracet – propyliodone – mimosine – trazodone – pyrithioxin – quinolinic acids – quinolinic acid – tolperisone – triprolidine – tropicamide – pyrimidines – buspirone – dipyridamole – epirizole – fursultiamin – hexetidine – minoxidil – mopidamol – morantel – nicarbazin – oxypurinol – pyrantel – pyrantel pamoate – pyrantel tartrate – pyrimethamine – pyrimidinones – alloxan – barbiturates – amobarbital – barbital – hexobarbital – mephobarbital – methohexital – murexide – pentobarbital – phenobarbital – primidone – secobarbital – thiobarbiturates – thiamylal – thiopental – cytosine – flucytosine – 5-methylcytosine – risperidone – ritanserin – sparsomycin – uracil – bromouracil – fluorouracil – tegafur – hydroxyphenylazouracil – orotic acid – pentoxyl – thiouracil – methylthiouracil – propylthiouracil – thymine – uracil mustard – pyrithiamine – thiamine – fursultiamin – thiamine monophosphate – thiamine pyrophosphate – thiamine triphosphate – trapidil – trimethoprim – trimethoprim-sulfamethoxazole combination – pyrrolidines – anisomycin – bepridil – clemastine – 3,4-dichloro-n-methyl-n-(2-(1-pyrrolidinyl)-cyclohexyl)-benzeneacetamide, (trans)-isomer – glycopyrrolate – imino furanoses – kainic acid – lincomycin – clindamycin – nafoxidine – nitromifene –