A nurse is teaching a client who has Multiple Sclerosis about a new prescription for baclofen. Which of the following instructions should the nurse include in the teaching?

A. "Monitor your blood pressure since hypertension can occur.": Baclofen primarily acts as a central nervous system muscle relaxant by stimulating GABA-B receptors. While it can cause hypotension in some cases, hypertension is not a common adverse effect. Blood pressure monitoring for high readings is generally not required unless indicated by comorbid conditions. B. "Do not take antihistamines with this medication.": Baclofen can cause central nervous system depression, including drowsiness, dizziness, and impaired coordination. Concomitant use of other CNS depressants, such as antihistamines, can increase the risk of excessive sedation and respiratory depression. Clients should avoid combining these medications. C. "Stop taking this medication immediately if you are drowsy.": Sudden discontinuation of baclofen, especially after prolonged use, can precipitate severe withdrawal symptoms, including hallucinations, seizures, and increased spasticity. Drowsiness is a common, expected side effect and should be monitored, but the medication should not be stopped abruptly. D. "Expect muscle spasticity to worsen initially.": Baclofen is prescribed to reduce muscle spasticity in multiple sclerosis. While some transient effects such as mild weakness may occur initially, spasticity should gradually decrease rather than worsen. Worsening spasticity is not a typical expectation when starting therapy.