Prescribing of unlicensed or off-label medicines is usually initiated in secondary care which can lead to problems when the patient returns to primary care. In one study, 1 in 3 patients discharged with an unlicensed medicine reported problems in obtaining the medicines in primary care . To ensure optimal clinical outcomes, it is essential that exactly the same medicine is prescribed in primary care as was prescribed for the patient in secondary care.
The GP should take all possible measures to minimise the risk of the pharmacist dispensing a product other than that intended.
- All instructions from the discharge summary letter should be carefully transferred to repeat prescriptions so the patient receives the exact same formulation.
- Include specific formulation needs e.g. alcohol-free
- Specify the source of supply e.g. a named ‘Specials’ manufacturer
A 4 kg neonate was discharged from hospital on Phenobarbital 20 mg three times a day (tds) prescribed as 2 ml tds of 50 mg/5 ml alcohol-free Phenobarbital suspension. The general practise prescribing system included a British Pharmacopoeia (BP) suspension of 15 mg/ 5 ml, and the GP prescribed and the pharmacy dispensed 6.8 ml (20 mg) tds of this suspension.
Four days later, the child was taken to hospital with lethargy and increased fitting. The 15 mg/5 ml preparation contains 38% alcohol and the volume of 6.8 mg administered to the child was similar to giving the neonate a glass of wine three times a day. As a neonate cannot metabolise alcohol as efficiently as an adult, this would have resulted in lethargy and decreased their seizure threshold, which explained the increased fitting.
To avoid this, the GP simply needed to specify on the prescription that the suspension should be 'alcohol-free'.
Incomplete information can lead to pharmacists dispensing inappropriate products
When conducting a medicines review, consider asking the following questions:
- Are there any problems with the medicine?
- Does the medicine taste ok?
- Is it easy to swallow?
- Is the patient / carer having to manipulate the formulation in any way? E.g. crushing tablets or opening capsules
A GP prescribed diclofenac tablets for a child with arthritis. A week later, the mother returned to the GP as she was concerned that the child was still in pain despite the medicine being given as directed. The GP discovered that the child had been dispensed 50 mg dispersible tablets and that the instructions from the pharmacy were to dissolve one tablet in 5ml of water and then give 1 ml of the liquid to the child, with the aim of providing a dose of 10 mg.
Dispersible tablets are usually licensed to aid administration of the whole dose. The content of dispersible tablets is not necessarily dissolvable, however, and if a proportion of the whole dose is required, the volume measured is unlikely to contain the amount of the medicine prescribed. Indeed, the dose actually dispensed could vary dramatically with each dose that they take – from as little as 2 mg up to 8 mg – and will rarely amount to the intended 10 mg. As a result, this child was not receiving a clinically effective dose and, therefore, had suboptimal pain relief.
The GP wrote a new prescription on which it was specified that a special was required. This ensured that the child received the intended dose, as the concentration of a special is more uniform and thus the amount of drug given in each dose is more consistent.
If you have any doubts, contact the original prescriber