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Name of Trust / logo Memo – shortage of supply To: From: Date: 16th July 2014 Re: Phentolamine mesilate injection Description of products affected Phentolamine mesilate injection is licensed for the management of hypertensive episodes that may occur in patients with phaeochromocytoma, for example during pre-operative preparation and surgical manipulation. It is also licensed for the diagnosis of phaeochromocytoma by Rogitine blocking test if other more specific tests are not available.1 Background A phaeochromocytoma is a catecholamine producing tumour arising mainly from the chromaffin cells of the adrenal medulla. Although it may be malignant, symptoms usually result from the excess secretion of catecholamines 2 and include hypertension, headaches, palpitations, and excessive sweating. If the effects of the release of catecholamines are not controlled, a life-threatening crisis ultimately occurs and may range from a shock-like syndrome with multiple organ failure to hypertensive crisis, depending on the predominance of the catecholamine secreted.3 Long-term management involves surgery but this must be preceded by pharmacological therapy to block the pressor and other effects of the excess catecholamines. This is important for symptom control, but is also necessary in asymptomatic patients undergoing surgery since massive release of catecholamines and resulting acute increases in blood pressure may occur during induction of anaesthesia or when the tumour is handled. Choice of therapy is not entirely clear since there is a lack of evidence from controlled studies.3 Alpha-blockers are used in the short-term management of hypertensive episodes in phaeochromocytoma, one of which is phentolamine, a short-acting intravenous agent used mainly during surgery.4 Its use for the diagnosis of phaeochromocytoma has been superseded by measurement of catecholamines in blood and urine.4. Intravenous phenoxybenzamine, a non-selective, long-acting a-blocker, is also used in the management of phaeochromocytoma but it has many side effects4 and there have been ongoing supply problems with this preparation.5 Why we are providing this information Alliance Pharmaceuticals/Novartis discontinued the UK production of phentolamine injection in August 2012 therefore use of other parenteral agents for the treatment of hypertensive episodes in phaeochromocytoma are required.6 Implications for patient care Since massive release of catecholamines and resulting acute increases in blood pressure may occur during induction of anaesthesia or when the tumour is handled, it is necessary to have available an alternative parenteral antihypertensive agent following the discontinuation of phentolamine injection and ongoing supply problems with phenoxybenzamine injection. Alternative agents and management options Although rarely used, the availability of a parenteral alpha blocker is considered essential for phaeochromocytomas, as well as other acute hypertensive crises, as alternative agents such as remifentanyl and GTN are not as effective in this situation and have a much slower onset of action. However, there are currently no alternative injectable alpha blockers available within the UK and importers are experiencing difficulties sourcing unlicensed formulations of either phentolamine or phenoxybenzamine injections.7 It is important to note that there are potential patient safety issues associated with use of imported products in terms of varying strengths of preparations available and Trusts are advised to check carefully which version of the product they receive and to highlight any differences to departments and practitioners so that patients are not exposed to incorrect doses of the drug. A possible oral alternative is phenoxybenzamine 10mg capsules (Dibenyline™) which is licensed for the management of hypertensive episodes associated with phaeochromocytoma.8 The Society for Endocrinology has published a protocol from the Royal Hallamshire in Sheffield for its use in the preparation of patients with phaeochromocytoma and paraganglioma for surgery.5 References 1. Alliance Pharmaceuticals. Rogitine Ampoules 10mg. SPC (date of revision 17/02/2006): http://www.medicines.org.uk/emc/medicine/128/SPC/Rogitine+Ampoules+10mg/ #INDICATIONS 2. Jones AG, Evans PH, Vaidya B, et al. Phaeochromocytoma. BMJ 2012; 344: e1042 3. Martindale. Phaeochromocytoma (Latest modification: 05-Jan-2011), accessed via Medicines Complete 30/6/2014 4. BNF 66; September 2013 5. Society for Endocrinology. Protocol using oral phenoxybenzamine to prepare patients with catecholamine-secreting phaeochromocytoma and paraganglioma for surgery (October 2010): http://www.endocrinology.org/policy/docs/1010_Protocol_using_oral_phenoxybenzamine.pdf 6. Alliance Pharmaceuticals/Novartis. Personal communication. 30th June 2014 7. Personal communication with importers; 30th June 2014 8. Amdipharm Mercury. Phenoxybenzamine. SPC (date of revision April 2012): http://www.medicines.org.uk/emc/medicine/25769 Original document prepared by: Guy’s and St Thomas’ NHS Foundation Trust Medicines Information Centre Prepared 14 Jul 2014 Document modified by: Name of individual at other centre using the product with modifications, centre, date For all correspondence please contact: Name of person at base hospital where memo is circulated (i.e. NOT the original author at Guy’s and St Thomas’ NHS Foundation Trust Disclaimer: The content of some of this memo is based on consensus opinion from clinical practitioners. Users should bear this in mind in deciding whether to base their policy on this document. Individual trusts should ensure that procedures for unlicensed medicines are followed where a foreign import drug is required in the interim.