From Ms S.C. Tulip, MRPharmS, and Mr D. Campbell, MRPharmS
SIR,—We read with interest the summary of the leading article in the
British Medical Journal about the potential problems associated with the interruption
of drug treatment prior to surgery (PJ, October 7, p510).
We would like to share our views on this with respect to children with cerebral
palsy, particularly those who take antiepileptic drugs.
Children with severe neurological problems, such as cerebral palsy, are frequently
referred for gastrointestinal surgery and orthopaedic procedures. These patients
are frequently maintained on continuous, and often complex, antiepileptic drug
regimens. They present a particular clinical problem pre- and post-operatively
because, when antiepileptic drug therapy is interrupted, seizure control can
become problematic. In this situation we suggest that the rectal route of administration
for certain anticonvulsants may be a useful and relatively simple alternative
for patients unable to take medication orally.
Pharmacokinetic data and literature evidence support the rectal administration
of carbamazepine, clonazepam, diazepam, lorazepam, phenobarbital and sodium
valproate. Vigabatrin and lamotrigine have pharmacokinetic properties which
may make them suitable for rectal administration (although there are no studies
to support this). Phenytoin and gabapentin are not well absorbed by the rectum
therefore their use rectally is unreliable and not recommended.
We have compiled guidelines following a detailed literature search and review
of pharmacokinetic data for antiepileptic drugs. These guidelines detail dosage,
formulation, and technique of administration, summarised in a quick reference
table. Our work was presented at the Fifth Congress of the European Association
of Hospital Pharmacists in March and has subsequently been submitted for publication.
However, we would be happy to send copies of the guidelines to anyone who is
interested.
We agree with the BMJ authors that problems associated with abrupt discontinuation
of drugs are not sufficiently recognised by the pharmaceutical industry. More
work should be done in this area to develop strategies to prevent the potentially
serious consequences of interrupting drug therapy when oral administration is
not possible. Greater emphasis on the potential use of the rectal route of administration
would certainly help in this respect.
Sarah Tulip
Research Pharmacist,
Centre for Health Studies,
University of Durham,
32 Old Elver,
Durham DH1 3HN
David Campbell
Head of Pharmacy,
North Durham Health Care NHS Trust