A nurse is evaluating teaching a client who has a new prescription for montelukast to treat asthma. Which of the following statements by the client indicates an understanding of the teaching?

Rebound congestion, also known as rhinitis medicamentosa, is a common adverse effect associated with the prolonged use of nasal decongestants. It occurs when the blood vessels in the nasal passages become dependent on the medication for constriction and lose their ability to regulate naturally. As a result, when the medication wears off, the nasal congestion worsens, leading to a cycle of continued use and worsening symptoms.

In this scenario, the patient's complaint of worsening nasal congestion despite using oxymetazoline every 2 to 4 hours for the past 5 days suggests the possibility of rebound congestion. The nurse should explain to the patient that prolonged or frequent use of nasal decongestants can lead to this effect and recommend gradually tapering off the medication use or discontinuing it altogether. The nurse may also suggest alternative non-medication strategies for managing nasal congestion, such as saline nasal sprays or steam inhalation.

A medication error refers to any preventable event that may cause or lead to inappropriate medication use or patient harm. In this case, the nurse administering a double dose of medication due to a failure to cut the pill in half is a medication error. It involves the administration of an incorrect dose, which can potentially result in harm or adverse effects for the patient.

The other situations mentioned do not necessarily indicate medication errors. A patient developing hives after starting an IV antibiotic could have an allergic reaction, and appropriate actions should be taken to address the reaction. A patient complaining of severe pain still present after receiving pain medication may require further assessment and intervention to manage their pain effectively. A patient refusing her morning medication is not a medication error but rather a patient's right to refuse treatment, and appropriate documentation and communication should be done in such situations.