Antihistamines Include:

First Generation ( Non-selective ) 

Ethanolamine- Carbinoxamine. Clemastine, Diphenhydramine.

Ethylenediamines- Pyrilamine, Triplennamine

Akylamines- Brompheneramine, Chlorpheniramine, Dexchlor pheniramine, Pheniramine,Triprolidine

Phenothiazines- Methidilazine, Promethizine, trimeprazine

Piperidines- Azatadine, Cyproheptadine, Phenindamine

Miscellaneous- Astemazole, Loratadine, Terfenadine

Second Generation ( Peripherally selective )

Phthalazinone - Azelastine Piperazine - Cetrizine

Refer - Chlorpheniramine maleate

Interacting drugs- summary

+ Doxycyline 

Barbiturate

 phenobarbital decreases doxycycline half life and serum levels which may persist for 2 weeks after barbiturate therapy is discontinued

Nausea and vomiting during pregnancy

Drowsiness, dizziness, vertigo, or disoreintation, nervousness,

dry mouth, irritability, g-i obstruction

Acute asthmatic attacks

Narrow angle glaucoma, urinary retention,

pyloric -duodenal obstruction, epilepsy,

severe cardio-vascular disorders

Indication-

Nausea and vomiting during pregnancy

Dosage-

Take with food or milk

2 tab of 10mg at bed time.

If required 1 more tablet in the morning and afternoon

Refer Chlorpheniramine maleate

Take with food or milk