Controlled Drug Information
Controlled drugs (CDs) are substances defined in the Misuse of Drugs Regulations (MDR) 2001 and the MDR (Northern Ireland) 2002 and are widely and routinely used in veterinary and human medicine. In the UK, the Home Office has responsibility for the regulations on the storage, supply, dispensing and destruction of CDs. In Northern Ireland, this responsibility falls to the Department of Health, Social Services and Public Safety (DHSSPS).
All CDs are listed in five Schedules in the MDR as follows:
- Schedule 1 CDs have little or no therapeutic value and are subject to the greatest restrictions. They include cannabis and are not used in veterinary medicines;
- Schedule 2 CDs have therapeutic value but are highly addictive such as pethidine. Their use is strictly controlled;
- Schedule 3 CDs are similar to Schedule 2 drugs but are less controlled. They include barbiturates and some benzodiazepines;
- Schedule 4 CDs contain most of the benzodiazepines and also anabolic and androgenic steroids;
- Schedule 5 CDs include preparations such as codeine or morphine in very low strength, so that they present little or no risk of misuse and are subject to the least controls.
A list of all authorised veterinary medicines which contain CDs is available below. The VMD produces a guidance note, VMGN 20 - Controlled Drugs which details the requirements for CDs when used in veterinary medicine.
- Recording Use and Wastage of Multi-dose Controlled Drug Preparations
- Misuse of Drugs Regulations 2001
- Police Contact for Controlled Drugs
- Currently Authorised Veterinary Medicines containing Controlled Drugs
The VMD has received a number of enquiries from veterinary surgeons and veterinary nurses relating to a recently authorised veterinary medicine, Comfortan.
This veterinary medicine contains the Schedule 2 Controlled Drug (CD) methadone, and in accordance with the prescribing Cascade, should be used in preference to any human medicine containing methadone, unless there is a sound clinical reason for using a different product and it is in the interest of animal welfare.
Comfortan is subject to strict controls under the Misuse of Drugs Regulations regarding prescription, storage, destruction and record keeping. Most of the queries received have related to record-keeping and stock reconciliation, as there can be marked discrepancies between the recorded amounts used, the volume of product left in the vial, and the total stated volume. This article provides some further information and guidance on this issue.
During manufacture of the product, the filling volume is set and checked to ensure that what is stated on the label is in the vial, and that it does not greatly exceed the nominal volume, which, in the case of Comfortan, is 10 ml. Therefore there will be minimal variation in fill volume when the product arrives at the practice.
However, once opened and in use, there will be some wastage within the needle and hub of the syringe each time product is withdrawn. If numerous small doses are withdrawn, there will be considerably more product lost to this 'dead space' than if fewer, larger doses are required.
It is not possible to quantify exactly how much product might be wasted in the syringe hub and needle but there are ISO standards which specify the maximum amount of dead space that is permitted in needles and syringes of different sizes and gauges. This information can be requested from manufacturers or wholesalers, so that the most suitable injection supplies can be sourced, but, in general, the smaller the gauge of needle or size of syringe, the less wastage will occur.
It is known that some veterinary surgeons utilise insulin syringes when withdrawing controlled drugs to minimise wastage. This is acceptable, although it is important to ensure that the syringe allows accurate measurement of the dose (i.e. in ml).
Other factors that may increase wastage might be the use of a separate, larger bore needle to withdraw the product from the vial before changing to a smaller needle to administer the product, and, potentially, also the process of expelling air from the syringe prior to injection can lead to further losses. Therefore careful selection of the injection equipment and good technique can help reduce wastage due to dead space.
Regardless of all steps taken to minimise wastage, both the Home Office and the VMD or RCVS Practice Standards Inspectors are aware that some wastage will be unavoidable and therefore we advise veterinary surgeons to record the volume (dose) they withdraw on each occasion and write off the vial as unusable (destroyed) in the Register once there is no usable volume remaining. See the following example of how wastage can be recorded in a Controlled Drugs Register.
Provided that Inspectors are satisfied that appropriate measures are in place to comply with the requirements of the Misuse of Drugs Regulations, the recording of small discrepancies that can be explained by wastage due to dead space is not considered a breach of the legislation.
Please note that there has been several amendments to the Misuse of Drugs Regulations 2001, these can also be found on the OPSI website.
Every Police Force throughout England, Scotland and Wales has a dedicated Controlled Drug Liaison Officer (CDLO) who is available to liaise with any veterinary practice within their area. A CDLO is able to offer advice on safe storage; auditing; destruction; suspicious activity; internal thefts; forged or stolen prescriptions; as well as 'current crime trends' and 'demands on the streets'; etc. A CDLO is authorised under the MDRs if a Constable or authorised by the PCT Accountable Officer if employed by the Police service as a civilian.
Current contact details for Controlled Drugs Liaison Officers can be found on the Association of Police Controlled Drugs Liaison Officers Website.