- What are antihistamine injections?
- What are examples of antihistamine injections available in the US?
- What are the side effects of antihistamine injections?
- Which drugs interact with antihistamine injections?
- What formulations of antihistamine injections are available?
- What about taking antihistamine injections during pregnancy or while breastfeeding?
Effects of antihistamines are prolonged if combined with MAO inhibitors like:
- phenelzine (Nardil),
- selegiline (Zelapar, Emsam, and Eldepryl),
- tranylcypromine (Parnate),
- procarbazine (Matulane),
- rasagiline (Azilect), and
- isocarboxazid (Marplan).
Antihistamine injections should be used with caution with MAO inhibitors.
What formulations of antihistamine injections are available?
Antihistamine injections are available in injection form.
- Diphenhydramine, promethazine, and dimenhydrinate are administered intramuscularly and intravenously.
- Hydroxyzine hydrochloride is administered only intramuscularly.
- Antihistamine injections are not recommended for administration via subcutaneous route.
What about taking antihistamine injections during pregnancy or while breastfeeding?
FDA lists diphenhydramine and dimenhydrinate as Pregnancy Category B and promethazine as Pregnancy Category C. Hydroxyzine does not have a Pregnancy Category. These categories mean that the safe and effective use of antihistamine injections is not established in during pregnancy; therefore, they should be used only if clearly needed.
It is not known whether injected antihistamine medication enters breast milk; therefore, it is best to be cautious before using antihistamine injections in women who are breastfeeding.
REFERENCE: FDA Prescribing Information.
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