Fluticasone (Flonase) a nasal glucocorticoid has been prescribed for a client with allergic rhinitis. The nurse teaches the client which is the most common side effect of continuous use.

Montelukast is a medicine used to treat and prevent asthma and allergic rhinitis. It can cause some side effects, such as stomach pain, headache, cough, or fever. However, some side effects are more serious and need to be reported to the provider.

According to the sources I found, the most serious side effect of montelukast that should be reported to the provider is depression. Depression is a mental health condition that can affect your mood, thoughts, and behavior. It can cause symptoms such as feeling sad, hopeless, or worthless; losing interest in activities you used to enjoy; having trouble sleeping or concentrating; or having thoughts of harming yourself or others.

Montelukast has been linked to neuropsychiatric events, such as agitation, aggression, sleep disturbances, suicidal thoughts and behavior (including suicide). The mechanisms underlying these events are not well understood, but they can occur at any time during treatment. Therefore, patients and caregivers should be alert for changes in behavior or new neuropsychiatric symptoms when taking montelukast. If these occur, they should discontinue montelukast and contact a healthcare provider immediately.

The other options are not listed as serious side effects of montelukast that need to be reported to the provider. Constipation, blurred vision, and palpitations are possible side effects of other medicines used to treat asthma or allergic rhinitis, such as corticosteroids, antihistamines, or beta-agonists. However, they are not specific to montelukast and may not be related to its use.

Dimenhydrinate is an antihistamine commonly used to treat motion sickness and vertigo. One of the common side effects of dimenhydrinate is dizziness. It can cause sedation and impair cognitive and motor functions. Therefore, the client should be advised to be cautious when engaging in activities that require alertness, such as driving or operating machinery. Monitoring for dizziness and taking appropriate precautions can help prevent accidents and ensure the client's safety.

The other options provided in the original response are incorrect:

1. Administer 24 hr before effects are desired: This is not a correct instruction for dimenhydrinate. The medication is typically taken 30 minutes to 1 hour before the desired effects, such as before travel to prevent motion sickness.
2. Expect an increase in salivation: Dimenhydrinate does not typically cause an increase in salivation. This is not a known side effect of the medication.
3. Observe for diarrhea: Diarrhea is not a common side effect of dimenhydrinate. While gastrointestinal disturbances can occur with some antihistamines, it is not typically associated with dimenhydrinate use.