Medicines approved for use in the UK are categorised in one of three ways:²

• General Sales List (GSL) medicines can be bought in places such as supermarkets and do not require the supervision of a pharmacist.
  
• Pharmacy (P) medicines can only be bought at a pharmacy and are sold under the supervision of a pharmacist.
  
• Prescription only medicines (POM) must be prescribed by a doctor, dentist, or exceptionally, another qualified health professional.

There is a range of exemptions from these restrictions which allow certain groups of health professionals, including paramedics, to sell, supply and administer particular medicines directly to patients. The exemptions are distinct from prescribing, which requires the involvement of a pharmacist in the sale or supply of the medicine. They also differ from the arrangements for Patient Group Directions (PGDs) as the latter must comply with specific legal criteria, be signed by a doctor or dentist and a pharmacist and authorised by an appropriate body. The exemptions that allow suitably trained ambulance paramedics to administer these drugs in specified circumstances exist under Part III of Schedule 5 to the Prescription Only Medicines (Human Use) Order 1997. For this purpose, a Paramedic is defined as being on the register of Paramedics maintained by the Health Professions Council pursuant to paragraph 11 of Schedule 2 to the Health Professions Order 2001.³

Diazepam and morphine are both controlled drugs regulated under the Misuse of Drugs Act 1971. This Act and its Regulations control the availability of drugs that are considered sufficiently ‘dangerous or otherwise harmful’, with the potential for diversion and misuse.⁴ The drugs which are subject to the control of the Misuse of Drugs Act 1971 are listed in Schedule 2 of the Act and are termed CDs. The Act establishes a series of criminal offences for their unauthorised, and therefore unlawful, possession, possession with intent to supply, supply, importation and unlawful production.

As many CDs have legitimate medical purpose, the Regulations made under the Misuse of Drugs Act 1971, authorise and govern certain activities that would otherwise be illegal under the Act. The Regulations identify those health care professionals who may legitimately possess and supply CDs. They also establish a regime of control around prescribing, administrating, safe custody, dispensing, record keeping and destruction or disposal.⁴

Ambulance paramedics serving at any approved ambulance station are able to administer diazepam and/or morphine sulphate injection (to a maximum of 20mg) for immediate necessary treatment of sick or injured persons. Currently there is wide variation in how CDs are obtained, stored and recorded by qualified paramedics working in the ambulance service.⁴

Drugs can be delivered in a variety of forms including tablets, capsules, solutions, inhalers, and by a variety of different routes – e.g. oral, rectal, intravenous, and intramuscular. A drug formulation may allow for selective targeting of specific tissues or may prevent systemic absorption. The formulation of the drug and the route administered determine the absorption and distribution of the drug.

Formulations for oral administration

Tablets

e.g. Aspirin.

Tablets are presented in a variety of different sizes, colours, shapes and types. The formulation of the tablet will be based upon the requirements of the drug, e.g. modified release tablets control the rate of release of a drug as it passes through the gastrointestinal tract. Tablets may be formulated to be chewed, held under the tongue (sublingual) or between the gum and the inside of the mouth (buccal), swallowed or to dissolve readily in liquid (soluble or effervescent).

Sprays

e.g. Glyceryl trinitrate (GTN).

Sprays such as GTN are designed to be taken sublingually because the first-pass mechanism destroys the majority of any drug that is swallowed.

Liquids

Liquids, such as Calpol, are usually sweet, syrup-like solutions often designed to be taken by children where a tablet may be inappropriate.

Formulations for rectal administration

There are many different drug formulations that use the rectal route including enemas and suppositories; these are not commonly used in prehospital emergency care. Most commonly used is the rectal tube for delivery of diazepam. Rectal diazepam is formulated to be absorbed via the rectal mucosa and is highly effective.

Formulations for nebulisation

Nebulisation involves the passage of a gas (usually oxygen in paramedic care) through a solution of drug to create a fine mist to be inhaled by the patient. The drugs most commonly administered via this route in emergency prehospital care are bronchodilators. Studies have shown that only between 10% and 30% of an inhaled drug is actually deposited in the lungs, the rest is generally swallowed and passes into the gastrointestinal tract.⁵

Formulations for injection

Injections are sterile solutions, emulsions or suspensions where an active ingredient is either dissolved or requires to be dissolved in an appropriate solution. The injection may come in a pre-filled syringe, Mini-Jet, powder with solute to be mixed, an ampoule or a vial.

Most preparations are single-dose formulations that provide the correct volume to allow withdrawal and administration of the appropriate dose using standard techniques. However, initial doses of certain drugs may require the administration of less than is in the delivery system. An example is morphine, which has a typical presentation of 10mg in 1mL, although the initial adult dose is usually between 2.5 and 5mg.

Documentation of drugs is a legal requirement and also essential for patient safety. Good practice related to documentation will minimise the risk of misunderstandings and ensure that there is some uniformity of practice across different health disciplines.

The following points should be noted:⁶

• Unnecessary use of decimal points should be avoided, e.g. 2mg not 2.0mg.
  
• Quantities of 1 gram or more should be written as 1g etc.
  
• Quantities less than 1 gram should be written in milligrams, e.g. 500mg not 0.5g.
  
• Quantities less than 1mg should be written in micrograms, e.g. 100 micrograms not 0.1mg.
  
• When decimals are unavoidable a zero should be written in front of the decimal point where there is no other figure, e.g. 0.5 mL not. 5 mL.
  
• Use of the decimal point is acceptable to express a range, e.g. 0.5 to 1g.
  
• ‘Micrograms’ and ‘nanograms’ should not be abbreviated nor should ‘units’.
  
• In medicine and pharmacy the term ‘millilitre’ (ml or mL) is used; cubic centimetre, (cc, or cm³) should not be used.
  
• Unit abbreviations are not followed by a full stop (mL, not m.L. or mL.).
  
• A single space is left between the quantity and the symbol (24kg not 24kg).
  
• Unit abbreviations are not pluralised (kg not kgs).
  
• As a rule, fractions are not used, only decimal notation (0.25kg not ¼kg).

General guidelines

Whilst in the possession of the ambulance service the responsibility for the safekeeping of the medicines rests with the Chief Executive. The security of medicines in specialist kits (e.g. paramedic bags) should be checked by pharmacy staff periodically, normally every 3 months, in accordance with locally agreed procedures. They should carry out inspections of medicines in specialist kits with reconciliation, where necessary. Prescription only medicines may only be issued by non-clinical staff for whom training and Standard Operational Procedures are agreed and in place.⁷

Security

Security should be of prime concern to the paramedic, especially when carrying and administering CDs. The Misuse of Drugs (Safe Custody) Regulations 1973 imposes controls on the storage of Schedule 1, 2 and Schedule 3 CDs.⁸

On station

Drugs should be kept in a locked storage area where general access is not possible; this helps to minimise the risk of unauthorised access and to deter abuse or misuse. Each service should have written procedures surrounding the signing in and out of medicines.

On vehicles

Where drugs are left on an unattended vehicle, the vehicle should be closed and locked – this alone is not adequate where CDs are involved.

‘Doctor’s bag’

A ‘doctor’s bag’ is a locked bag, box or case for home visits, etc. which should be kept locked at all times, except when in immediate use. The person in lawful possession of this bag, or an individual authorised by them, must always retain the keys. Legal precedent holds that such a bag is regarded, once locked, as a suitable receptacle for storing CDs, but a locked vehicle is not.⁴

Stability

Medicines should be stored where they will not be subject to substantial variations in temperature. It is important that medicines are not stored close to heaters in ambulance vehicles as some may be damaged by heat.

Some medicines require storage under well-defined conditions, such as in a refrigerator. If ambulance services carry such medicines, provision should be made to meet these requirements.

Stock control

Stock rotation must be in operation to prevent the accumulation of ‘old’ stocks; this applies to vehicle or personal drug issue and drug supplies on station. It is the responsibility of the attending paramedic to ensure that all personal/vehicle drugs are checked and replenished, where necessary, on a day-to-day basis. Normally a supervisor will be responsible for monitoring the rotation of drugs held in station stores.

Oral administration

Note – Chewing aspirin is not a pleasant experience and current prehospital guidance suggests that it may be swallowed with water or chewed.⁹ The American Heart Association recommends that the tablet is chewed for speed of effect despite the unpleasant taste.¹⁰

Administration of Inhaled drugs (nebulised)

It is possible to nebulise bronchodilators in an intubated patient – the nebuliser should be connected to the oxygen supply as normal and then connected via a ‘T’ piece to the catheter mount immediately after the bag-valve ventilator or mechanical ventilator. It is essential that the nebuliser is maintained in an upright position to ensure that sufficient gas passes through the drug to aerosolise it.

Subcutaneous Injection

A subcutaneous (SC) injection is given beneath the skin into the connective tissue or fat immediately beneath the dermis. This route is generally used for small volumes of drugs (0.5 mL or less) that do not irritate tissue. The maximum volume that should be used for this route is 2mL.¹¹ It is not commonly used in the emergency situation due to the slow absorption rates although there may be benefit from the prolonged effects when given via this route.

Traditionally, SC injections have been given at a 45° angle into a raised skin fold.¹² However, there is a recommendation that with the introduction of shorter needles (5, 6 or 8mm), the injection is now administered at an angle of 90°.^13,14 The skin should be pinched up to lift the adipose tissue away from the underlying muscle, especially in thin patients. When injecting at 45° or into the buttock areas, which have the densest fat layer, lifting up of the skin fold is not required.¹⁵ Traditional teaching has suggested that an attempt be made to aspirate once the needle is inserted in order to confirm that the needle is not in a blood vessel. This is no longer considered necessary as piercing of a blood vessel in a SC injection has been shown to be very rare.¹⁶

Suitable sites include the lateral aspects of the upper arm, lower abdomen (umbilical region), and the upper outer quadrant of the buttocks.¹¹ The lower back may also be used if necessary.

Procedure

Select the correct equipment:

• Appropriate sized syringe
  
• 25-gauge needle
  
• Filter needle
  
• Cleansing swab
  
• Drug to be administered.

Intramuscular Injection

Intramuscular injections deliver medication into well perfused muscle, providing rapid systemic action and absorbing relatively large doses – from 1mL in the deltoid site to 5mL elsewhere in adults (these values should be halved for children).¹¹ Administration of an IM injection is a complex psychomotor task that requires considerable dexterity and underpinning knowledge.¹⁷ It is a two-handed procedure requiring the practitioner to use one hand to stabilise the injection site, and the other to administer the injection.

Site selection is of vital importance as the effect of the medication can be enhanced or diminished depending upon the selected site; complications are also associated with the chosen site.¹⁷ The most common complications are muscle contracture and nerve injury.^18,19 Site selection should take into consideration the patient’s general physical status and age, and the amount of drug to be given. The proposed site for injection should be inspected for signs of inflammation, swelling, and infection, and any skin lesions should be avoided.

Older and emaciated patients are likely to have less muscle than younger, more active patients. The proposed sites should be assessed for suficient muscle mass and where there is reduced muscle mass it is helpful to ‘bunch up’ the muscle before injecting.¹¹

There are five sites considered to be useful for IM injections although paramedics tend to use only two of these:

• The deltoid muscle of the upper arm.
  
• The dorsogluteal site using the gluteus maximus muscle, the traditional site in the UK.²⁰ Complications are associated with this site as there is a possibility of damaging the sciatic nerve or the superior gluteal artery if the needle is misplaced. Several studies show that even in mildly obese patients, injections into the dorsogluteal area are more likely to be into adipose tissue rather than muscle, and consequently slow the absorption rate of the drug.²¹
  
• The ventrogluteal site is a safer option which accesses the gluteus medius muscle. This site is recommended as the primary location for IM injections as it avoids all major nerves and blood vessels and there have been no reported complications.²¹ In addition, the thickness of adipose tissue over the ventrogluteal site is relatively consistent at 3.75 cm as compared to 1–9 cm in the dorsogluteal site. This ensures that a standard size 21-gauge needle will usually penetrate the gluteus medius muscle area.¹¹

Techniques

The angle of needle entry may contribute to the pain of the injection. For many years it has been stated that intramuscular injections should be given at a 90° angle to ensure the needle reaches the muscle and to reduce pain; most of the literature tends to support this contention.²² One study seems to indicate that the 90° angle is less important in terms of the depth of injection as an angle of 72° penetrates to 95% of the depth of a needle angled at 90°.²³ Based on this, the practitioner should endeavour to give the injection with the needle perpendicular to the patient’s body, which should ensure that it falls within the range of 72–90°.¹⁷

Fewer needlestick injuries and improved site accuracy have been reported when the hands are positioned near the intended entry site.¹¹ To ensure entry at the correct angle, the heel of the dominant palm should rest on the thumb of the non-dominant hand. It is suggested that by holding the syringe between the thumb and forefinger, a firm and accurate thrust of the needle at the correct angle can be achieved.¹¹

The traditional method of giving an intramuscular injection has been to stretch the skin over the site to reduce the sensitivity of nerve endings and to insert the needle in a dart like action at 90° to the skin.²⁴ Two different techniques are also available, the Z track technique and the air bubble technique.

Z-track technique

The Z-track technique is believed to reduce pain, as well as the incidence of leakage.²⁵ It involves pulling the skin downwards or to one side at the intended site, which moves the cutaneous and subcutaneous tissues by 1–2cm. The needle is inserted and the injection given. Ten seconds should be allowed before removing the needle to facilitate diffusion of the medication into the muscle. On removal, the retracted skin is released so that the tissues close over the deposit of medication thus preventing leakage from the site. Exercising the limb afterwards is believed to assist absorption of the drug by increasing blood flow to the area.²¹

Aspiration should be practised in IM injections. If a needle is mistakenly placed in a blood vessel, the drug may be given intravenously.

Air bubble technique

This technique arose historically from the use of glass syringes which required an added air bubble to ensure an accurate dose was given. It is no longer necessary to allow for the dead space in the syringe and needle, as plastic syringes are calibrated more accurately than glass ones, and it is no longer recommended by manufacturers.²¹ Studies comparing this technique with the Z-track technique have been inconclusive with one suggesting that the air bubble technique is more successful at preventing leakage than the Z-track technique,²⁶ whilst the findings of the other were inconclusive.²⁷ There are issues related to the accuracy of the dose when using this technique – it may significantly increase the dose.²⁸ Further research needs to be undertaken on this method as it is relatively new to the UK; it is recommended that the Z-track technique be used in preference.²⁹

Procedure (Z-track)²⁹

Rectal administration

The rectal route is not frequently used by paramedics, but it is suitable for patients who are having seizures where it may not be possible to cannulate. The drug is absorbed rapidly through the rectal mucosa.

Equipment required

• Clean, non-sterile gloves
  
• Lubricating jelly
  
• Rectal tube.