Final answer:
If a nurse encounters a patient with a lactose allergy, caution should be taken when administering montelukast as some formulations contain lactose. Allergies to cellulose, zolpidem, aspirin, xylitol, or ampicillin are generally not directly relevant to montelukast administration, but vigilance is always necessary if the medication's specific excipients are not known.
Step-by-step explanation:
When a nurse is preparing to administer montelukast to a client, it is critical to check for allergies that may cause an adverse reaction to the medication. The specific allergies that should alert the nurse to hold the medication and contact the prescribing health care provider would be to excipients in montelukast such as lactose, which is a known ingredient in some formulations of montelukast tablets. Allergies to cellulose, lactose, zolpidem, aspirin, xylitol, or ampicillin may indicate potential cross-reactivity or excipient reactions, except for lactose (which is sometimes present in montelukast tablets). Since the question lists specific substances, it is crucial to recognize that zolpidem is a sleep medication unrelated to montelukast, aspirin is a nonsteroidal anti-inflammatory drug that may trigger asthma exacerbations in some individuals but is not an allergy specifically related to montelukast, and ampicillin is an antibiotic, not an excipient in montelukast. Cellulose and xylitol are generally not known to cause severe allergic reactions. It's essential to verify the medication's formulation before proceeding in case of patient-reported allergies.