Source: FDA, National Drug Code (US) Revision Year: 2019
SEMPREX-D Capsules are indicated for relief of symptoms associated with seasonal allergic rhinitis such as sneezing, rhinorrhea, pruritus, lacrimation, and nasal congestion. SEMPREX-D Capsules should be administered when both the antihistaminic activity of acrivastine and the nasal decongestant activity of pseudoephedrine are desired (see CLINICAL PHARMACOLOGY). The efficacy of SEMPREX-D Capsules beyond 14 days of continuous treatment in patients with seasonal allergic rhinitis has not been adequately investigated in clinical trials.
SEMPREX-D Capsules have not been adequately studied for effectiveness in relieving the symptoms of the common cold.
The recommended dosage for adults and adolescents 12 years and older is one capsule administered orally, every 4 to 6 hours four times a day.
There have been no reports of overdosage with Semprex-D Capsules. In the clinical trial program and in international post-marketing experience, there have been two reported overdoses with acrivastine. Doses were 72 mg and 322 mg. Both patients recovered without sequelae. Adverse events included trembling, stridor, loss of consciousness and possible convulsions in the first patient and somnolence in the second.
Since acrivastine and pseudoephedrine have pharmacologically different actions, it is difficult to predict how an individual will respond to overdosage with SEMPREX-D Capsules. However, acute overdosage with SEMPREX-D Capsules may produce clinical signs of either CNS stimulation or depression. Overdosage of sympathomimetics has been associated with the following events: fear, anxiety, tenseness, restlessness, tremor, weakness, pallor, respiratory difficulty, dysuria, insomnia, hallucinations, convulsions, CNS depression, arrhythmias, and cardiovascular collapse with hypotension. Treatment for overdosage with SEMPREX-D Capsules should follow general symptomatic and supportive principles.
In a placebo-controlled, double-blind clinical trial in 18 healthy male subjects, single doses of acrivastine up to 400 mg (50 times the recommended antihistaminic dose) produced only a weak vagolytic effect, manifested as an increase in heart rate, and did not cause cardiac repolarization delays (i.e., increased QTc). Daily doses of acrivastine up to 2400 mg (75 times the recommended antihistamine dose) in an uncontrolled study in 38 cancer patients produced a 15-beats-per-minute increase in mean heart rate and occasional episodes of nausea and vomiting. The effects of acrivastine plus pseudoephedrine at single or multiple doses higher than the recommended daily dose of SEMPREX-D Capsules (i.e., 32 mg acrivastine plus 240 mg pseudoephedrine) on heart rate and cardiac repolarization have not been investigated in clinical trials.
The mean LD50 (single, oral dose) of acrivastine is greater than 4000 mg/kg (23600 mg/m2 or 1000 times the recommended human daily dose) in rats and greater than 1200 mg/kg (3600 mg/m2 or 153 times the recommended human daily dose) in mice. The mean LD50 (single, oral dose) of pseudoephedrine hydrochloride is 2206 mg/kg (13015 mg/m2 or 73 times the recommended human daily dose) in rats and 726 mg/kg (2178 mg/m2 or 12 times the recommended human daily dose) in mice. The toxic and lethal concentrations of acrivastine and pseudoephedrine in human biologic fluids are not known. Based upon pharmacokinetic screening data from clinical trials, the maximum plasma acrivastine concentration after dosing with acrivastine 8 mg was 393 ng/mL and the maximum plasma pseudoephedrine concentration after dosing with pseudoephedrine hydrochloride 60 mg was 1308 ng/mL.
Store at 15°C to 25° C (59°F to 77° F) in a dry place and protected from light.
Keep out of the reach of children.
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