Dizziness, somnolence, fatigue and dry mouth have been reported with an overdose of fexofenadine hydrochloride. Single doses of up to 800 mg and doses of up to 690 mg twice daily for one month or 240 mg once daily for one year were administered to healthy volunteers without clinically significant adverse effects compared to placebo. The maximum tolerated dose of fexofenadine hydrochloride has not been established. Results This cohort study of a source cohort of 1.3 million pregnancies in Denmark from 2001 to 2016 included all pregnancies exposed to fexofenadine. No association has been established between the use of fexofenadine during pregnancy and the risk of serious birth defects, spontaneous abortion, preterm birth, short for gestational age or stillbirth. For the treatment of allergic rhinitis, fexofenadine is just as effective as cetirizine, but is associated with less drowsiness than cetirizine. [20] Fexofenadine has also been shown to inhibit papule and histamine-induced flare-ups significantly more than loratadine or loratadine,[21] but slightly less effective than levocetiridine. [22] There are limited data on the use of fexofenadine during pregnancy. In 20 years, only 13 severe cases have been reported, which is considered low. Pregnant or breastfeeding women are also advised to consult a doctor or pharmacist before taking this product. There are no data on breast milk content following administration of fexofenadine hydrochloride. However, when terfenadine was given to nursing mothers, it was found that fexofenadine is excreted in breast milk. Therefore, Allevia 120 mg is not recommended for mothers who breastfeed their babies.
Breastfeeding women should only use Allevia 120 mg if instructed to do so by a doctor. Due to three over-the-counter NEAs (loratadine, fexofenadine, and cetirizine) available on the market, Aetna does NOT consider concomitant treatment with TWO non-sedating antihistamines medically necessary. Antacids containing aluminum or magnesium should not be taken within 15 minutes of fexofenadine, as they reduce its absorption by almost 50%. [5] This is not thought to be due to a change in pH (in fact, absorption may actually increase under an increasingly alkaline pH), but to the formation of metal complexes with charged/polar units on fexofenadine. As proposed by Shehnaza et al (2014), various sites of the molecule would be responsible for this interaction, including the nitrogen piperidine, the carboxylic acid group (-COOH) and the two hydroxyl groups (-OH). [28] The Agency for the Regulation of Drugs and Health Products has added Allevia (fexofenadine hydrochloride) 120 mg antihistamine tablets to the general sales list. Objective To investigate the risk of adverse foetal outcomes associated with the use of fexofenadine during pregnancy. Table 3 presents the results of sensitivity analyses of the primary endpoints. For the analysis of serious congenital malformations, the prevalence of CR was 1.12 (95% CI, 0.82-1.52) for fexofenadine use compared with loratadine use in the first trimester, 1.02 (95% CI 0.77-1.36) for pregnancies with fexofenadine use in the first trimester compared to pregnancies not exposed to fexofenadine during pregnancy but recently taken fexofenadine before the onset of pregnancy, and 1.03 (95% CI 0.84-1.26) for fexofenadine use compared with cetirizine use in pregnancy, where exposure duration was prolonged throughout pregnancy. For analyses of spontaneous abortions, the RRs were 0.94 (95% CI, 0.81-1.10) for fexofenadine use compared with loratadine use in pregnancy and 0.81 (95% CI 0.70-0.94) for pregnancies with fexofenadine use compared with pregnancies not exposed to fexofenadine during pregnancy but recently used by fexofenadine before the onset of pregnancy. For analyses based on the number of prescriptions filled for fexofenadine (1 or ≥2 prescriptions filled), no differences were observed in the estimates for serious birth defects and spontaneous abortions.
Table 2 shows the results of consistent analyses of spontaneous abortions and secondary outcomes. The proportional hazard hypothesis was respected for all analyses of fetal death. Spontaneous abortions occurred in 413 pregnancies (8.4%) with fexofenadine use and 439 pregnancies (9.0%) with cetirizine (HR, 0.93; 95% CI 0.82-1.07), corresponding to an ARD of -0.05% (95%, CI, -0.17% to 0.06%) per 1000 pregnancies. In patients with seasonal allergic rhinitis who received fexofenadine hydrochloride up to 240 mg twice daily for 2 weeks compared to placebo, no significant difference in QTc intervals was observed. In addition, no significant changes in QTc intervals were observed in healthy volunteers who received fexofenadine hydrochloride up to 60 mg twice daily for 6 months, 400 mg twice daily for 6.5 days and 240 mg once daily for one year compared to placebo. Fexofenadine at concentrations 32-fold higher than the therapeutic concentration in humans had no effect on the delayed K+ rectifier channel cloned from the human heart. Taking erythromycin or ketoconazole while taking fexofenadine increases plasma fexofenadine levels, but this increase does not affect the QT interval. The reason for this effect is probably due to transport-related effects, particularly p-glycoprotein (p-gp). [5] Erythromycin and ketoconazole are inhibitors of p-gp, a carrier protein involved in preventing intestinal absorption of fexofenadine. When p-gp is inhibited, fexofenadine may be better absorbed by the body and increase its plasma concentration more than expected.
[ref. needed] Pregnancies with fexofenadine and cetirizine in a pairwise comparison, matched to inclination values. OR indicates the odds ratio. The carcinogenic potential of fexofenadine hydrochloride has been evaluated using terfenadine studies with supporting pharmacokinetic studies showing exposure to fexofenadine hydrochloride (via plasma AUC). No evidence of carcinogenicity was observed in rats and mice administered terfenadine (up to 150 mg/kg/day). The results of sensitivity analyses corresponding to the limitation of exposure periods until the end of the first trimester or week 22 of pregnancy for the analysis of severe birth defects or spontaneous abortions, as well as the results of analyses of severe birth defects in single pregnancies and induced abortions, are given in Table 8 of the supplement.