Fexofenadine (Allegra) Contraindications and Precautions
- neonates
- terfenadine hypersensitivity
- breast-feeding
- children
- driving or operating machinery
- pregnancy
- renal disease
- renal failure
- renal impairment
Fexofenadine (Allegra) Contraindications and Precautions
Do not use fexofenadine in patients with a history of terfenadine hypersensitivity due to the similarity in chemical structure.
Fexofenadine should be used cautiously in patients with renal impairment associated with renal disease or renal failure. Peak plasma concentrations were 87% and 111% greater in patients with mild (CrCl 41 - 80 ml/min) to severe (CrCl 11 - 40 ml/min) renal impairment, respectively. Mean elimination half-lives were 59% and 72% longer, respectively, than in normal volunteers. Peak plasma concentrations in dialysis patients (CrCl <= 10 ml/min) were 82% greater and half-life was 31% longer than in normal volunteers. Patients with mild to severe renal impairment should be given half the initial dose due to reduced clearance of fexofenadine.
Fexofenadine is classified as pregnancy category C. Results of animal studies have revealed an absence of mutagenicity or infertility. Teratogenicity was not observed in rats given approximately 15 times the maximum daily oral dose in humans based on an AUC comparison. Decreased pup weight gain and survival occurred in rats given 3 times the maximum daily oral dose in humans. There have been no adequate and well-controlled studies on the use of fexofenadine in human pregnancy. Fexofenadine should be used during pregnancy only when the benefits of therapy outweigh the risks.
It is unknown if fexofenadine is excreted into human breast milk. Fexofenadine should be used during breast-feeding only when the benefits of therapy outweigh the risks.
The incidence of drowsiness was 1.3% in patients receiving fexofenadine monotherapy (vs placebo 0.9%). Patients should be warned about undertaking hazardous tasks (e.g., driving or operating machinery) while taking fexofenadine, although the risk is relatively low.
The safety and effectiveness of fexofenadine in children under 6 years of age have not been established. Antihistamines generally should not be used in neonates due to the possibility of paradoxical CNS stimulation.
[ Last revised: 1/4/2006 10:06:00 PM ]
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