Preferred Sample Type


Suitable Specimen Types

  • Serum
  • EDTA Plasma
  • Li Hep Plasma
A minimum of 500 ┬Ál of plasma/serum is required.

Specimen Transport

First class post

Sample Processing in Laboratory

Place sample in toxicology rack.

Sample Preparation

None required

Turnaround Time

3 days.

Sample Stability

Keep refrigerated. 4 degrees.


General Information

Cyclizine is an antihistaminic drug with antiemetic and sedative effects that has been in use since 1954 for the prevention or treatment of motion sickness. The usual adult oral dose for motion sickness is 50 mg taken 30 minutes before travel and repeated 4-6 hours as needed, not to exceed 200 mg daily. A 50 mg i.m or i.v dose is frequently used for the treatment of post-operative vomiting or acute cardiac chest pain, and it may be repeated every 8 hours.

The adverse effects seen with cyclizine therapy include dry mouth, headache, blurred vision, drowsiness, tachycardia, urinary retention and restlessness. Cyclizine overdosage can cause central nervous system depression or stimulation, euphoria, hypertension, convulsions, coma and death from respiratory paralysis. 

Patient Preparation

For TDM, sample should be taken prior to dose. If toxicity is suspected, take sample at earliest opportunity


Cyclizine measured by HPLC-DAD.


Please note this assay is not currently UKAS accredited

Reference Range

Therapeutic use of cyclizine typically associated with concentrations of up to 0.25 mg/L. Toxicity is generally associated with concentrations > 0.75 mg/L. (Schulz et al. Critical Care 2012, 16:R136)


  • EQA Scheme?: Yes

The laboratories at Heartlands Hospital, Good Hope Hospital and Solihull Hospital form part of the services provided by University Hospitals Birmingham and are UKAS (United Kingdom Accreditation Service) accredited to the ISO 15189:2012 standard. For a list of accredited tests and other information please visit the UKAS website using the following link:

  • Heartlands, Good Hope and Solihull Hospital pathology laboratories are a UKAS accredited medical laboratory No.8217
  • United Kingdom Health Security Agency laboratory is a UKAS accredited medical laboratory No.8213

Tests not appearing on the UKAS Schedule of Accreditation currently remain outside of our scope of accreditation. However, these tests have been validated to the same high standard as accredited tests and are performed by the same trained and competent staff.

For further test information, please visit the test database:

Protection of personal information - Laboratory Medicine comply with the Trust Data Protection policy and have procedures in place to allow the Directorate and its employees to comply with the Data Protection act  1998 and associated best practice and guidance.

For further information contact Louise Fallon, Quality Manager, 0121 424 1235