Azatadine
Azatadine is an antihistamine, related to cyproheptadine, with anti-serotonin, anticholinergic (drying), and sedative effects. Azatadine is in the same class of drugs as chlorpromazine (Thorazine) and trifluoperazine (Stelazine); however, unlike the other drugs in this class, azatadine is not used clinically as an anti-psychotic.
Mechanism of effect
Antihistamines such as azatadine appear to compete with histamine for histamine H1- receptor sites on effector cells. The antihistamines antagonize those pharmacological effects of histamine which are mediated through activation of H1- receptor sites and thereby reduce the intensity of allergic reactions and tissue injury response involving histamine release.
Pharmacodynamic
Antihistamines antagonize the vasodilator effect of endogenously released histamine, especially in small vessels, and mitigate the effect of histamine which results in increased capillary permeability and edema formation. As consequences of these actions, antihistamines antagonize the physiological manifestations of histamine release in the nose following antigen-antibody interaction, such as congestion related to vascular engorgement, mucosal edema, and profuse, watery secretion, and irritation and sneezing resulting from histamine action on afferent nerve terminals.
Pharmacokinetics
Absorption: Well absorbed after oral administration.
Metabolism: HepaticDosage
Usual Adult Dose for Allergic Reaction
1 to 2 mg orally twice a day
Usual Adult Dose for Allergic Rhinitis
1 to 2 mg orally twice a day
Usual Adult Dose for Urticaria
1 to 2 mg orally twice a day
Usual Pediatric Dose for Allergic Reaction
<12 years: not recommended
>=12 years: 1 to 2 mg orally twice a day
Usual Pediatric Dose for Allergic Rhinitis
<12 years: not recommended
>=12 years: 1 to 2 mg orally twice a day
Usual Pediatric Dose for Urticaria
<12 years: not recommended
>=12 years: 1 to 2 mg orally twice a day
Side effects
Headache , nausea , dry mouth , Blurred vision , vertigo , palpitations , dry eyes , aplastic anemia, , Diplopia , difficulty urinating , tirednessInteractions
Acetylcholine , potassium citrate , Topiramate , Zonisamide , Sodium Oxybate , propoxyphene , glycopyrrolate topicalAlerts
- glaucoma or increased pressure in the eye;
- a stomach ulcer;
- an enlarged prostate, bladder problems or difficulty urinating;
- an overactive thyroid (hyperthyroidism);
- hypertension or any type of heart problems; or
Points of recommendation
Take azatadine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.
Take each dose with a full glass of water.
Azatadine can be taken with or without food.
Store azatadine at room temperature away from moisture and heat.
Take the missed dose as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only your next regularly scheduled dose. Do not take a double dose of this medication unless otherwise directed by your doctor.
Use caution when driving, operating machinery, or performing other hazardous activities. Azatadine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.
Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while you are taking azatadine.
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