| I-amino alkyl ethers (ethanol amines) | *presence of cHo | Hydroxyzine*** | ***2nd generation antihistaminic >has no CNS activity *antiemetic in pruritis ,minor tranqulizer |
| Diphenhydramine (Benadryl) | *antiemetic *antitussive *sedative | Buclizine HCL (Bucladin-S)*** | ****it has bulky structure >high lipid sol ,CNs depressent pass BBB ,antiemetic and antihistaminic properties |
| Dimenhydrinate (Dramamine) | *as diphenhydramine + theophilline salt *treat of motion sickness *analysis by Volhard (xxs AgNo3) #amm scn ,ferric alum indicator | Meclizine di HCl*** | ***uses as anti nauseant in prevention of motion sickness ,T of nausia & vomitting associated e Vertigo |
| Doxylamine*** | ****good night time hyp when compared e secobarbital *syn from acetophenon and grignard then hyd >socl2 | III- propylamine derivetives (pheniramines) | *adv >less sedation than other grps |
| Carbinoxamine maleate*** | ****racemic mix *it is example of cpds has more actiity in levo *related to Doxylamine *l (s) isomer superimposible upon more active (s) of chlorpheniramine | Pheniramine maleate (Avil) and chloro derivative | *chloro ,bromo pheniramine + potency by 20 fold ,*d isomer exhibit greater potency *syn from acetophenone + HCHO |
| II- ethylenediamines | *less antiemetic *less anticholenergic than amino alkyl ether | unsat olefinic analog 1-pyrrobutamine phosphate*** | ***long acting ,slow onset of action *active form (trans ,E) |
| Clemastine fumarate | *long duration of action than carbinoxamine ,start action after 12 h ,® is active >exception ,c more sterioselective *syn from amino pyridine | 2-Triprolidine HCl (Actifed)*** | ****most active H1 antagonist *activity due to trans isomer *syn |
| Tripelennamine HCL (pyribenzamine) | *2 forms citrate & HCl salt (bitter) so use citrate in oral adm (liq form ,more palatable) | 3-Dimethindane maleate (Fenistril)*** | ****antihistaminic activity only on levo rotatory isomer |
| cylclic basic chain analogues 1-Clemizole | 2N sep by 2c | Tricyclic ring system (phenodiazine & dibenzocycloheptanes) | *SAR *branched alkyl chain *c chain more potent invitro (due to presence of 3c) *have tranqulizing and antiemetic activites & potentiate analgesics and sedatives |
| 2-antazoline (Antistin) eye drops*** | ***phosphate salt less irritating to cornea of eye than HCL *2 N sep by 2c | Promethazine Hcl (phenergam) | *racemic mix (d,L) ,potent antiemetic ,sedating |
| 3-Thenaldine | *2 N sep by 3c | Trimerazine | |
| piperazine derivatives (cyclizines) | adv >more useful antiemetic *motion sickness *slow onset ,long duration | Methdilazine HCl (Tacaryl) | |
| cylizine (Marezine) ,chlorocyclizine | *is cl substituted >more activity *if dichloro or cl in position 2 or 3 >less act | isothiopendyl HCl | N containing isostere of phenothiazine (Azaphenothizine) |
| Methixene (it is azaphenothizine) | *moderate H1 antagonist ,marked antimuscarinic activity used for 1-sympotomatic T of Parkinsonism | ||