Issues for surgery
Risk of withdrawal if omitted (see Further information).
Risk of relapse of schizophrenia or bipolar disorder if omitted.
Risk of QT-interval prolongation if continued (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.
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.
Interactions with common anaesthetic agents
Central Nervous System (CNS) depression
Also see Interactions with other common medicines used in the perioperative period.
Asenapine has 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
Asenapine 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.
Co-administration of asenapine 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 – avoid for amisulpride and paliperidone, for risperidone*
- 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.
Asenapine has CNS depressant effects which may be additive with antiemetics that also have CNS depressant effects such as cyclizine, droperidol and prochlorperazine.
Hypotension
Asenapine can increase the risk of hypotension when used concomitantly with droperidol and prochlorperazine.
QT-interval prolongation
Co-administration of asenapine 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*
*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).
**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.
Antimicrobials
Also see QT-interval prolongation above
Myelosuppression
Concomitant use of asenapine 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 asenapine 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.
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 – Reagila® (asenapine) 10mg sublingual tablets. Recordati Pharmaceuticals Limited. Accessed via www.medicines.org.uk 20/08/2019 [date of revision of the text July 2017]