Methylphenidate


  Issues for Surgery


Risk of exacerbation of attention deficit hyperactivity disorder (ADHD) if omitted.

Risk of perioperative hypertension and arrhythmias if continued (see Interaction(s) with Common Anaesthetic Agents).

Risk of antagonising effect of sedative drugs if continued (see Interaction(s) with Common Anaesthetic Agents).


  Advice in the Perioperative period


Elective Surgery

Omit dose(s) on day of operation1, 2, 3, 4, 5, 6, 7, 8, 9.

Emergency Surgery

If dose(s) already taken on day of operation warn session Anaesthetist to avoid halogenated anaesthetics (see Interaction(s) with Common Anaesthetic Agents below).

Monitor blood pressure (BP) closely.

Post-operative Advice

Restart on first post-operative day.

Patients with Dysphagia
Xaggitin®, Concerta® XL and Delmosart® prolonged-release preparations are not suitable for patients with dysphagia10. Discuss alternative treatment with patient’s Psychiatrist.

Patients with Restricted Gastrointestinal Lumen 
Concerta® XL and Delmosart® prolonged-release preparations are non-deformable; they are not suitable for patients with restricted gastrointestinal lumen e.g. strictures10. Discuss alternative treatment with patient’s Psychiatrist.


  Interaction(s) with Common Anaesthetic Agents


Inhalational Anaesthetics

Methylphenidate is an indirectly-acting sympathomimetic, and might be expected to increase the risk of hypertension and arrhythmias if used with inhalational anaesthetics11, 12.

Manufacturers of various brands of methylphenidate advise withholding on the day of surgery if use of halogenated anaesthetics (e.g. sevoflurane) is planned due to the potential for a hypertensive reaction1, 2, 3, 4, 5, 6, 7, 8, 9.

Antagonism of Sedative Drugs

Methylphenidate increases the analgesic effects of opioids, including morphine, hydromorphone and oxycodone, but reduces the sedative and respiratory depressant effects11.

A case report describes difficulty sedating a child taking methylphenidate despite administration of midazolam and ketamine. Methylphenidate may possibly antagonise the effect of sedative drugs, and may also be associated with an increased incidence of vomiting11 - hence withholding methylphenidate on the day of surgery may be prudent for any form of sedation or general anaesthesia7, 11.

CNS Excitation (Serotonin Syndrome)

The manufacturers note that serotonin syndrome has been reported when methylphenidate has been co-administered with serotonergic medications1. They recommend monitoring for symptoms of serotonin syndrome with concomitant use of serotonergic products and discontinuing methylphenidate if serotonin syndrome is suspected1. There are no case reports describing interactions between methylphenidate and serotonergic drugs in the literature so the clinical relevance of this is not known; however, amphetamines are known to increase serotonin release so bear the possibility in mind if co-prescribing opioids that are weak serotonin reuptake inhibitors (e.g. fentanyl, pethidine).


  Interaction(s) with other Common Medicines used in the Perioperative Period


Linezolid

Concomitant treatment with methylphenidate and linezolid is predicted to increase the risk of elevated blood pressure – avoid concomitant use1, 10.

Seizure threshold

Methylphenidate may lower the seizure threshold1, 11; concurrent use with other drugs that lower the seizure threshold (e.g. tramadol) might result in additive effects11.

CNS Excitation (Serotonin Syndrome)

The manufacturers note that serotonin syndrome has been reported when methylphenidate has been co-administered with serotonergic medications1. They recommend monitoring for symptoms of serotonin syndrome with concomitant use of serotonergic products and discontinuing methylphenidate if serotonin syndrome is suspected1. There are no case reports describing interactions between methylphenidate and serotonergic drugs in the literature so the clinical relevance of this is not known; however, amphetamines are known to increase serotonin release so bear the possibility in mind if co-prescribing serotonergic medications (e.g. ondansetron, methylthioninium chloride).


  Further Information


Withdrawal

Abrupt cessation is not recommended10; careful supervision is needed as withdrawal may unmask depression and chronic over-activity1.


  References


  1. Summary of Product Characteristics – Concerta XL® (methylphenidate) 18 mg prolonged-release tablets. Janssen-Cilag Ltd. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text October 2018]
  2. Summary of Product Characteristics – Delmosart® (methylphenidate) 18mg Prolonged-release Tablets. Accord-UK Ltd. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text January 2018]
  3. Summary of Product Characteristics – Equasym XL® (methylphenidate) 10 mg Capsules. Shire Pharmaceuticals Limited. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text June 2018]
  4. Summary of Product Characteristics – Matoride XL® (methylphenidate) 18 mg Prolonged-release Tablets. Sandoz Limited. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text June 2019]
  5. Summary of Product Characteristics – Medikinet XL® (methylphenidate) 10 mg modified-release capsules, hard. Flynn Pharma Ltd. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text February 2019]
  6. Summary of Product Characteristics – Methylphenidate Hydrochloride 10 mg Tablets. Mylan. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text April 2017]
  7. Summary of Product Characteristics – Ritalin® (methylphenidate) 10 mg Tablets. Flynn Pharma Ltd. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text August 2019]
  8. Summary of Product Characteristics – Xaggitin XL® (methylphenidate) 18mg Prolonged-release Tablets. Martindale Pharma, an Ethypharm Group Company. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text February 2019]
  9. Summary of Product Characteristics – Xenidate XL® (methylphenidate) 18 mg Prolonged-release Tablets. Mylan. Accessed via www.medicines.org.uk 06/09/2019 [date of revision of the text April 2017]
  10. Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 31st August 2019]
  11. Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 31st August 2019]
  12. Dexamphetamine. In: Brayfield A (Ed), Martindale: The Complete Drug Reference. London: The Royal Pharmaceutical Society of Great Britain. http://www.medicinescomplete.com [Accessed 31st August 2019]