Issues for surgery
Risk of withdrawal if omitted (see Further information).
Risk of relapse of schizophrenia or bipolar disorder if omitted.
Risk of Intraoperative Floppy Iris Syndrome (IFIS) in patients undergoing cataract surgery when continued (see Further information).
Risk of QT-interval prolongation if rcontinued (see Interactions with common anaesthetic agents and Interactions with other common medicines used in the perioperative period).
Advice in the perioperative period
Elective and emergency surgery
Continue.
Patients undergoing cataract surgery
Ensure the ophthalmologist/cataract surgeon is aware the patient is taking risperidone, which has alpha-adrenoceptor blocker activity (see Further information).
Post-operative advice
If a long Nil by Mouth (NBM) period is anticipated, or if there are concerns regarding enteral absorption, advice on alternative preparations/routes should be sought from a psychiatrist.
Patients receiving depot antipsychotic preparations
If a patient’s usual depot antipsychotic intramuscular injection is due whilst an inpatient ensure correct product is prescribed, it is administered by a healthcare professional who is aware of the correct injection technique (including use of z-track technique) and rotate injection site.
Interactions with common anaesthetic agents
Central Nervous System (CNS) depression
Also see Interactions with other common medicines used in the perioperative period.
Atypical antipsychotics have CNS depressant effects which may be additive with other medicines that also have CNS depressant effects such as:
- benzodiazepines
- inhalational anaesthetics and intravenous anaesthetics
- local anaesthetics
- opioids
Consult British National Formulary for available drugs in each class.
Hypotension
Risperidone can increase the risk of hypotension when used concomitantly with inhalational and intravenous anaesthetics.
QT-Interval prolongation
Also see Interactions with other common medicines used in the perioperative period.
Risperidone is known to cause QT-interval prolongation. Co-administration with other medicines known to prolong the QT-interval must be based on careful assessment of the potential risks and benefits for each patient.
Anaesthetic agents that may be used in the perioperative period that are known to, or predicted to, prolong the QT-interval include:
- desflurane, isoflurane, sevoflurane*
- thiopental (theoretical)**
*monitor ECG if concurrent use unavoidable; if risk factors for QT-prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia) use greater caution.
**monitor ECG with concurrent use if risk factors for QT-prolongation are also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia).
Interactions with other common medicines used in the perioperative period
CNS Depression
Also see Interactions with common anaesthetic agents for information on opioids.
Risperidone has CNS depressant effects which may be additive with antiemetics that also have CNS depressant effects such as cyclizine, droperidol and prochlorperazine.
Hypotension
Risperidone can increase the risk of hypotension when used concomitantly with droperidol and prochlorperazine.
Hypokalaemia
Dexamethasone and hydrocortisone may cause hypokalaemia (potentially increasing the risk of torsades de pointes) with risperidone – use with caution. If hypokalaemia occurs, corrective action should be taken and QT-interval monitored.
QT-interval prolongation
Co-administration of risperidone with medicines known to prolong the QT-interval must be based on a careful assessment of the potential risks and benefits for each patient since the risk of torsade de pointes may increase.
Medicines that may be used in the perioperative period that are known to prolong the QT-interval include:
- ciprofloxacin*
- clarithromycin*
- domperidone - avoid
- droperidol*
- erythromycin – particularly intravenous*
- granisetron*
- haloperidol - avoid
- loperamide*
- ondansetron*
- prochlorperazine*
*monitor ECG with concurrent use if risk factors for QT-interval prolongation also present (increasing age, female sex, cardiac disease, and some metabolic disturbances e.g. hypokalaemia).
Antimicrobials
Also see QT-interval prolongation above.
Macrolides
Clarithromycin is predicted to increase the exposure to risperidone through inhibition of CYP3A4.
Myelosuppression
Concomitant use of risperidone with the following can increase the risk of myelosuppression:
- co-trimoxazole
- linezolid
- trimethoprim
Whilst single surgical prophylactic doses should not pose a problem, monitor for side effects and consider reducing atypical antipsychotic dose if a prolonged course of clarithromycin or ciprofloxacin is required and monitor full blood count if a prolonged course of myelosuppressive medication is required.
Further information
Withdrawal
Abrupt withdrawal of risperidone may result in symptoms including sweating, insomnia, tremor, anxiety, nausea and vomiting.
Venous thromboembolism (VTE)
Cases of VTE have been reported with antipsychotic drugs, although a causal relationship has not been established. Patients with schizophrenia often have acquired risk factors for VTE; identify any risk factors and consider if thromboprophylaxis is indicated post-operatively.
Intraoperative Floppy Iris Syndrome (IFIS)
IFIS has been observed during cataract surgery in some patients on or previously treated with tamsulosin. Isolated reports have also been received with other alpha-adrenoceptor blockers and the possibility of a class effect cannot be excluded. As IFIS may lead to increased procedural complications during the cataract operation current or past use of medications with alpha-adrenoceptor blocking activity, including risperidone, should be made known to the ophthalmic surgeon in advance of surgery.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 20th August 2019]
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 20th August 2019]
Summary of Product Characteristics – Risperdal® (risperidone) 0.5mg Film-Coated Tablets. Janssen-Cilag Ltd. Accessed via www.medicines.org.uk 20/08/2019 [date of revision of the text September 2018]
Summary of Product Characteristics – RISPERDAL CONSTA® (risperidone) 25 mg powder and solvent for prolonged-release suspension for injection. Janssen-Cilag Ltd. Accessed via www.medicines.org.uk 20/08/2019 [date of revision of the text September 2018]