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For information regarding cardiovascular adverse events (e.g., cardiac arrest, ventricular arrhythmias), please see CONTRAINDICATIONS and WARNINGS. In some cases, recognition of severe arrhythmias has been preceded by episodes of syncope. Similarly, rare cases of hypotension, palpitations, and dizziness have also been reported with Astemizole use, which may reflect undetected ventricular arrhythmia.

In studies the usual maintenance dose of Astemizole was 10 mg once daily.

TABLE 1 - Astemizole, Adverse Reactions Percent of Patients Reporting Controlled Studies*

Adverse Event Astemizole Placebo Classical**
(N = 1630) (N = 1109) (N = 304)
% % %
Central Nervous System
Drowsiness
7.1 6.4 22.0
Headache
6.7 9.2 3.3
Fatigue
4.2 1.6 11.8
Appetite increase
3.9 1.4 0.0
Weight increase
3.6 0.7 1.0
Nervousness
2.1 1.2 0.3
Dizzy
2.0 1.8 1.0
Gastrointestinal System
Nausea
2.5 2.9 1.3
Diarrhea
1.8 2.0 0.7
Abdominal pain
1.4 1.2 0.7
Eye, Ear, Nose, and Throat
Mouth dry
5.2 3.8 7.9
Pharyngitis
1.7 2.3 0.3
Conjunctivitis
1.2 1.2 0.7
Other
Arthralgia 1.2 1.6 0.0
* Duration of treatment in Controlled Studies ranged from 7 to 182 Days
** Classical Drugs: Clemastine (N = 137); Chlorpheniramine (N = 100); Pheniramine Maleate (N = 47); d-Chlorpheniramine (N = 20)

Adverse reaction information has been obtained from more than 7500 patients in all clinical trials. Weight gain has been reported in 3.6% of astemizole treated patients involved in controlled studies, with an average treatment duration of 53 days. In 46 of the 59 patients for whom actual weight gain data was available, the average weight gain was 3.2 kg.

Less frequently occurring adverse experiences reported in clinical trials or spontaneously from marketing experience with Astemizole include: angioedema, asymptomatic liver enzyme elevations, bronchospasm, depression, edema, epistaxis, myalgia, palpitation, paresthesia, photosensitivity, pruritus, and rash.

Marketing experiences include isolated cases of convulsions. A causal relationship with Astemizole has not been established.