Antihistamines Include:

Ethanolamine- Carbinoxamine. Clemastine, Diphenhydramine.

Ethylenediamines- Pyrilamine, Triplennamine

Akylamines- Brompheneramine, Chlorpheniramine, Dexchlor pheniramine, Triprolidine Phenothiazines- Methidilazine, Promethizine

Piperadines- Azatadine, Cyproheptadine, Phenindamine

Miscellaneous- Astemazole, Loratadine, Terfenadine

Interacting drugs - summary

Cyproheptidine +

Fluoxetine

 pharmacologic effects of flouoxetine may be decreased or reversed

Antihistamine, cold, urticaria.. 

Antihistamines Include:

Ethanolamine- Carbinoxamine. Clemastine, Diphenhydramine.

Ethylenediamines- Pyrilamine, Triplennamine

Akylamines- Brompheneramine, Chlorpheniramine, Dexchlor pheniramine, Triprolidine

Phenothiazines- Methidilazine, Promethizine

Piperadines- Azatadine, Cyproheptadine, Phenindamine

Miscellaneous- Astemazole, Loratadine, Terfenadine

CNS depression, paradoxical CNS excitation,

weight gain, increase in appetite,

hypersensitivity, dryness of mouth,

thickened respiratory secretion,

blurring of vision, bradycardia followed by tachycardia and arrhythmias,

GI disturbances and blood dyscarias.

Glaucoma, pyloric stenosis, acute asthamatic attack, paralytic ileus.

Special precautions:

Elderly, neonates, lactation, driving, BHP, epilepsy.

Indications:

Antihistamine, cold, urticaria..

Dosage:

Individualise dose.

Adults- 4 to 20mg daily.Initiate therapy with 4mg 3 times/day.

Majority require 12 to 16mg/day, occasionally as much as 32mg/day.

Do not exceed 0.5mg/kg/day.

Children -(7 to 14 years )- 4mg 2 or 3 times/day. Do not exceed 16mg/day.

Children(2 to 7 years) 2mg 2 or 3 times/day. Do not exceed 12mg/day..

1. Inform patients of a history of glaucoma, peptic ulcer, urinary retention, or pregnancy before starting antihistamine therapy

2. May cause nervousness, insomnia, and dry mouth

3. May cause drowsiness, or dizziness(except astemazole,loratadine, and tefenadine)

4. Patients should observe caution while driving or performing other tasks requiring alertness, coordination or physical dexterity.

5. Avoid alcohol and other CNS depressants (eg, sedatives, hypnotics, tranquilizers)

6. May cause GI upset, take with food. Take Astemazole on an empty stomach, at least 2 hours after or 1 hour before a meal. Take Lorantidine on an empty stomach.

7. Avoid prolonged exposure to sunlight, may cause photosentivity.

8. Do not crush or chew sustained releae preparations

9.Astemazole/ Terfenadine: Patients should not take these agents if they have hepatic dysfunction or if they are also receiving ketoconazole, itraconazole or erythromycin

10. Phenothiazines- Patients should report any involuntary muscle movements or unusual sensitivity to sunlight.

May be taken with meals to reduce GI discomfort