Which oral medication should the nurse anticipate being prescribed for a pregnant client with a trichomonal infection?

Metronidazole is the appropriate medication for treating trichomonal infections during pregnancy. This antibiotic is effective against Trichomonas vaginalis, the organism responsible for the infection. It works by disrupting the DNA and inhibiting the nucleic acid synthesis of the protozoan, leading to its destruction.

The use of metronidazole is supported by the fact that it is generally considered safe for use during pregnancy, particularly in the second and third trimesters, although caution and professional guidelines should always be followed. It is effective and offers a clear therapeutic benefit to pregnant women diagnosed with this type of infection.

Other medications listed have different indications or uses. Clindamycin, while useful for certain bacterial infections, is not typically indicated for trichomoniasis. Amoxicillin is an antibiotic primarily used to treat bacterial infections and does not target the protozoan responsible for trichomoniasis. Azithromycin is an antibiotic effective against specific bacterial infections and is not the first-line treatment for trichomoniasis. Thus, metronidazole remains the most suitable choice for this condition in pregnant individuals.