Dyslipidemia Drug Summary

Antihistamines and Antiallergics (Oral)

Drug Dosage Remarks
Children  Adult 
First Generation 
Azatadine 6-12 years old: 0.5-1 mg PO 12 hourly  1-2 mg PO 12 hourly  Adverse Reactions
  • Most common: CNS effects (drowsiness, lassitude, dizziness, incoordination, paradoxical stimulation)
  • Other common: CNS effects (headache, psychomotor impairment); Antimuscarinic effects (dry mouth, viscous secretions, urinary retention, blurred vision)
  • Occasionally can cause GI effects (nausea and vomiting, diarrhea, epigastric pain, anorexia or increased appetite); CV effects (palpitations, arrhythmias, rarely hazardous ventricular arrhythmias); Hypersensitivity reactions (rashes, angioedema, anaphylaxis); Other effects (convulsion, sweating, myalgia, tremor, hypotension)
    • Promethazine may sometimes cause photosensitivity or jaundice
Special Instructions
  • Avoid use in patients who need mental alertness (eg driving or using machines) and with alcohol intake
  • Use with caution in patients with angle-closure glaucoma, urinary retention, prostatic hyperplasia, epilepsy, renal or hepatic impairment
    • Reduction of dosage may be needed
Brompheniramine  2-6 years olf: 1 mg PO 4-6 hourly
>6-12 years old: 2 mg PO 4-6 hourly
12 years old: 4 mg PO 4-6 hourly 		 4 mg PO 4-6 hourly 
Buclizine  -  25-50 mg/day PO 
Max dose: 100 mg/day 
Chlorpheniramine  Regular-release:
1-2 years old: 1-2 mg PO 12 hourly
2-5 years old: 1 mg PO 4-6 hourly
Max dose: 6 mg/day
6-12 years old: 2 mg PO 4-6 hourly
Max dose:  12 mg/day
Extended-release:
6-11 years old: 4 mg PO 12 hourly 		 Regular-release: 4 mg PO 4-6 hourly
Max dose: 24 mg/day
Extended-release: 8-12 mg PO 12 hourly 
Clemastine  1-3 years old: 0.25-0.5 mg PO 12 hourly
3-6 years old: 0.5 mg PO 12 hourly
6-12 years old: 0.5-1 mg PO 12 hourly
 1 mg PO 12 hourly
Max dose: 6 mg/day 
Cyproheptadine  2-6 years old: 2 mg PO 8-12 hourly
Max dose: 12 mg/day
7-14 years old: 4 mg PO 8-12 hourly
Max dose: 16 mg/day 		 4 mg PO 8 hourly
May increase as necessary up to 
Max dose: 32 mg/day 
Dexchlorpheniramine1  2-6 years old: 0.5 mg PO 4-6 hourly
Max dose: 3 mg/day
6-12 years old: 1 mg PO 4-6 hourly
Max dose: 6 mg/day 		 Regular-release: 2 mg PO 4-6 hourly
Max dose: 12 mg/day
Extended-release: 6 mg PO 12 hourly 
Dimethindene  -  Regular-release: 1-2 mg PO 8 hourly 
Diphenhydramine (Dimenhydrinate)  2-<6 years old: 6.25 mg PO 4-6 hourly
6-12 years old: 12.5-25 mg PO 4-6 hourly
>12 years old: 25-50 mg PO 6-8 hourly 		 25-50 mg 6-8 hourly
Max dose: 300 mg/day 
Homochlorcyclizine  -  10-20 mg PO 8 hourly 
Hydroxyzine  6 months-6 years old: 
Initial dose: 5-15 mg/day in divided doses 
Max dose: 50 mg/day in divided doses
>6 years old:
Initial dose: 15-25 mg/day in divided doses
Max dose: 100 mg/day in divided doses
 25 mg PO 24 hourly at night
May increase to 25 mg PO 6-8 hourly 
Mebhydrolin napadisylate  <2 years old: 50-100 mg/day PO in divided doses
2-5 years old: 50-150 mg/day PO in divided doses
5-10 years old: 100-200 mg/day PO in divided doses
>10 years old: 100-300 mg/day PO in divided doses 		 100-300 mg/day PO 
Mequitazine  5 mL/10 kg body weight/day PO  5 mg PO 12 hourly 
Oxatomide  Initial dose: 0.5 mg/kg PO 12 hourly
Optimal dose: 0.5-1 mg/kg PO 12 hourly 		 30 mg PO 12 hourly 
Pheniramine  5-10 years old: 22.5 mg PO 8 hourly
>10 years old: (syrup) 15-30 mg PO 8-12 hourly or 
(tab) 45 mg PO 8 hourly
Max dose: 3 mg/kg/day 		 45 mg PO 8 hourly
Max dose: 3 mg/kg/day 
Piprinhydrinate 1.5 mg PO 8 hourly  3-6 mg PO 8 hourly 
Promethazine  2-5 years old: 5-15 mg/day PO or
5 mg PO 12 hourly
>5-10 years old: 10-25 mg PO 24 hourly or 5-10 mg PO 12 hourly
Max dose: 25 mg/day 		 Initial dose: 10 mg PO 12 hourly or 25 mg PO 24 hourly at night
Max dose: 20 mg PO 8 hourly 
 Second Generation
Acrivastine  >12 years old: 8 mg PO 8 hourly  8 mg PO 8 hourly 

Adverse Reactions

  • Cause little or no drowsiness and antimuscarinic effect as compared to first generation antihistamines
    • Cetirizine may cause higher incidence of drowsiness as compared with other second generation antihistamines

Special Instructions

  • Use with caution in patients who need mental alertness (eg driving or using machineries), may rarely affect performance of skilled task
  • Use with caution in patients with hepatic or renal impairment, epilepsy, and in the elderly
Cetirizine  6 months- 1 year: 2.5 mg PO 24 hourly
1-2 years old: 2.5 mg PO 12 hourly 
2-6 years old: 5 mg PO 24 hourly or
2.5 mg PO 12 hourly
6-12 years old: 10 mg PO 24 hourly or 5 mg PO 12 hourly 		 10 mg PO 24 hourly 
Desloratadine  2-5 years old: 1.25 mg PO 24 hourly
6-11 years old: 2.5 mg PO 24 hourly 		 5 mg PO 24 hourly 
Ebastine  >6 years old: 5 mg PO 24 hourly  10-20 mg PO 24 hourly 
Fexofenadine  6 months-<2 years old: 15 mg PO 12 hourly
2-11 years old: 30 mg PO 12 hourly 		 Regular-release: 60 mg PO 12 hourly
Extended-release: 120-180 mg PO 24 hourly 
Ketotifen fumarate (Ketotifen hydrogen fumarate)  1 mg PO 12 hourly  1 mg PO 12 hourly or 
1 mg PO 24 hourly in the evening 
Levocetirizine  6 months-5 years old: 1.25 mg PO 24 hourly
6-11 years old: 2.5 mg PO 24 hourly
Max dose: 2.5 mg/day
≥12 years old: 5 mg PO 24 hourly
Max dose: 5 mg/day 		 5 mg PO 24 hourly
Max dose: 5 mg/day 
Loratadine1  2-12 years old:
>30 kg: 10 mg PO 24 hourly
≤30 kg: 5 mg PO 24 hourly 		 10 mg PO 24 hourly 

1Combination with corticosteroids are available. Please see the latest MIMS for specific formulations and prescribing information.

This is h3 text test - PD 4/6/26

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