From the Guidelines
Loratadine and cetirizine are the preferred antihistamines to use during pregnancy, as they have been shown to be safe and effective in numerous studies, including a recent review published in 2020 1. These second-generation antihistamines can be taken at standard adult dosing: cetirizine 10mg once daily or loratadine 10mg once daily. They are preferred because they don't cross the blood-brain barrier significantly, causing less drowsiness while effectively treating allergy symptoms. Some key points to consider when using antihistamines during pregnancy include:
- Using the lowest effective dose for the shortest duration needed to control symptoms
- Consulting with a healthcare provider before starting any medication during pregnancy
- Being aware of potential interactions with other medications
- Considering alternative treatments, such as intranasal corticosteroids, for allergic rhinitis First-generation antihistamines like diphenhydramine (Benadryl) at 25-50mg every 4-6 hours as needed are also considered safe but may cause drowsiness and should be used with caution, especially when driving or operating machinery, as noted in a study published in 2008 2. Chlorpheniramine is another acceptable option at 4mg every 4-6 hours as needed, although it may have sedative effects, as mentioned in a guideline published in 2007 3. It's essential to weigh the benefits of symptom relief against any potential risks and to consult with a healthcare provider before starting any medication during pregnancy. Additionally, it's crucial to be aware of the potential risks associated with other medications, such as oral decongestants, which may be related to rare birth defects, as noted in a report published in 2005 4.
From the FDA Drug Label
If pregnant or breast-feeding: if breast-feeding: not recommended if pregnant: ask a health professional before use. If pregnant or breast-feeding, ask a health professional before use.
The safe antihistamines to use during pregnancy are not explicitly stated in the provided drug labels.
- Cetirizine and loratadine require consultation with a health professional before use during pregnancy [5] [6]. It is recommended to consult a health professional before using any antihistamine medication during pregnancy.
From the Research
Safe Antihistamines During Pregnancy
- Second-generation antihistamines such as cetirizine and loratadine are considered safe to use during pregnancy 7
- First-generation antihistamines are generally not recommended due to potential risks 7, 8
- H1 antihistamines have been found to not be associated with an increased risk of major malformation or other adverse fetal outcomes in some studies 9
Antihistamines to Avoid During Pregnancy
- Intranasal antihistamines 7
- First-generation antihistamines 7, 8
- Mycophenolate mofetil, methotrexate, cyclosporine, azathioprine, and zilueton 7
General Considerations
- Every drug used in pregnancy carries a risk for teratogenicity and careful risk/benefit assessment should be done before prescribing them 8
- None of the antihistamines available today have been categorized as safe during pregnancy, and control studies are available for certain first-generation drugs regarding their safety in pregnancy, but the newer agents require further studies to be declared safer in pregnancy 8
- The use of H-1-antihistamines during pregnancy has been very controversial due to possible teratogenic effects of these drugs 8