ADHD

Question

Do medicines for CF and the drug methylphenidate go together

Answer

Thank you for your question.

Indeed different medications can influence each other. Since patients with CF already take a lot of medicines it is important when a medicine is added to check whether
- the edition of this extra medicine is safe for the patient
- There are interactions between the new and already prescribed drug
- a change in dosing of one of the medicines is necessary

Methylphenidate (Ritalin®) is a medicine known to interact with several other medications. With this we mean that the transformation or brake down(metabolism) of one medicine is influenced by the presence of another medicine e.g. by using similar brake down systems in the liver or during excretion by the kidneys. Indeed many medicines are being transformed in the liver and/or excreted by the kidneys.

The list of medications that interact with Ritalin® does not include a drug that is commonly used in a treatment of patients with cystic fibrosis. There is however an interaction with Linezolid, an antibiotic used to treat infection with specific bacteria such as MRSA (Methicilline resistant Staphylococcus aureus).
When Linezolid and Ritalin® are used concomitantly there is an increased risk of ‘serotoninerg syndrome’. In this syndrome the patient is confused, sweats, has a high fever, has chills and tense muscles. Extra attention for these symptoms are necessary when the patient is on both medicines.

Another problem concerns the use of Ritalin® and gases that are used to put patients to sleep. These gases indeed make the patient more vulnerable to the side effects of methylphenidate, such as increased blood pressure. Care should be taken when a patient on Ritalin® needs general anesthesia. It is advised to stop Ritalin® the day of the surgery or anesthesia.

Finally we need to mention that methylphenidate can influence appetite and as a consequence of that growth. Since growth and weight evolution are very important for patients with CF, extra attention to evolution of weight and height is needed when a patient needs Ritalin®.

We advise the patient to always mention all the medicines that he takes when he visits a doctor. The doctor will then check if a specific problem could occur in case new medication is started.

We hope that this information is useful for you.
Dr. T. Van Ackere, Professor K. De Boeck

02.01.2012