Non_Medical_Prescribing

Case Study 1: Trimethoprim for lower Urinary Tract Infection. Background. For the purpose of this case study and to protect anonymity, the patient will be referred to as Sarah. The patient is a 29 year old woman, whom presented herself to Accident and Emergency with lower abdominal ache, frequency of micturition and dysuria for 24 hours. The author works as an Advanced Nurse Practitioner (ANP) and was asked to perform an assessment of Sarah as well as diagnose and discuss treatment options with her. Working under the supervision of her designated medical practitioner, the author diagnosed Sarah with a lower urinary tract infection and prescribed 200 mg of trimethoprim, to be taken orally, at 12 hour intervals for 3 days, until the course of treatment was completed. The decision to prescribe this drug will be examined throughout this case study. 2.3: Makes an accurate assessment and diagnosis and can generate treatment options Non- Medical Prescribers (NMP) are responsible and accountable for the assessment of patients with undiagnosed or diagnosed conditions and for decisions about clinical management required, including prescribing (Scottish Executive Health Department, 2006). Effective communication is the basis for good prescribing practice. According to Lewis and Allen (2002), this means building a relationship built on trust and mutual respect. This can be achieved by listening to and understanding patients’ expectations, needs and beliefs. Working in partnership with patients’ will help them to make informed choices, understand their treatment and encourage them to take responsibility for their health. To build rapport, the author began the consultation with a greeting, introduction and explaining the role of an ANP. A consultation provides the opportunity for patients to tell their story with an unfolding of symptoms, feelings and problems. However, stories are usually told in unstructured ways and the use of an assessment model helps the practitioner to obtain the information required for accurate diagnosis and subsequent safe prescribing practice (Kaufman, 2008). The assessment model used by the author is an integrated care pathway used across NHS Lanarkshire. This assessment model can be criticised for its focus on viewing patients by condition or pathology (Reed and Watson, 1994). However, the author feels that the tool is appropriate as it provides a structured way of consulting, when time constraints coupled with no immediate access to patients records, can increase the chance of achieving the correct diagnosis. The author rarely has access to medical records as it can take time for the hospital clerical staff to obtain the records for the storage facilities. This was indeed the case for Sarah. As discussed previously, Sarah is a 29 year old woman who presents with lower abdominal ache, frequency of micturition and dysuria for 24 hours. She had been previously fit and well, taking no prescription, homeopathic or over the counter medicines. She also denied any drug allergies. It is safe prescribing practice to check these details to minimise the potential for drug interactions with a newly prescribed medicine (Nuttall, Rutt-Howard, 2011, p143). She had no previous past medical history until March 2010 when she began having recurrent lower urinary tract infections, each episode treated effectively with trimethoprim or amoxicillin by her GP until August 2010 when she was admitted to hospital with Pyelonephritis (upper urinary tract infection). According to Butler and Courtenay (2002), UTI is thought to occur in women as the urethra is short and in close proximity to the vagina and rectum, this tends to offer little protection against the microorganisms into the bladder from these areas. The main risk factors include sexual intercourse, previous history of UTI and pregnancy (Butler and Courtenay, 2002). The main causative organism is Escherichia coli, accounting for 70% of cases, with the remaining 30% being caused by Klebsiella pneumonia, proteus mirabilis and staphylococcus saprophyticus (Moore,2005, p249). Sarah was worried that with her previous experience of urinary tract infections (UTI) would lead to hospital admission. The author reassured Sarah that a full examination and appropriate tests would be carried out in order to achieve the correct diagnosis and treatment options. The author asked Sarah a series of questions about her signs and symptoms in order to make a differential diagnosis. She had been well since her hospital admission with Pyelonephritis in 2010 and had experienced no further signs or symptoms of UTI until 24 hours ago, when she noticed lower abdominal ache which she initially thought was symptoms of her menstrual cycle, which started two days previously. However, she then felt a burning pain whilst passing urine, coupled with frequency of micturition; symptoms which point towards a lower UTI, due to bladder or urethral irritation. The majority of UTIs are caused by uropathogenic bacteria which, according to Moore (2005, p249), are among the most common bacterial infection found in women. Patients with an upper tract UTI are generally more severely ill than patients with lower UTI. Symptoms of upper UTI include loin pain, fever and vomiting (Chan and Chan, 2006, pp55- 54). Sarah denied having symptoms which may have suggested an upper Upper UTI. Sarah had no worrying signs of severe, systemic infection. Her vital signs were checked, and there was no elevation of pulse, temperature and respiratory rate which can all point towards signs of septic shock (Sanders et al, 2005, p153). After checking Sarah’s vital signs, a sample of her urine was obtained for testing. Urinalysis is a cheap, simple test that can be performed, using reagent sticks, to indicate a variety of disorders and diseases (Wells, 2007). The reagent stick showed evidence of leucocytes: Leucocyte esterase is an enzyme found in leucocyte granules that can be used in the diagnosis of UTI (Rigby and Gray, 2005). The urine also tested positive for nitrite: Nitrite is produced by the action of bacterial nitrite reductase on dietary nitrate. The presence is suggestive of a UTI but its absence does not exclude infection (Wells, 2007). In addition to testing Sarah’s urine for infection, and with her consent, a pregnancy test was performed, and the results were negative. Pregnancy is a risk factor for UTI as discussed previously, and it can influence the choice of antibacterial prescribed. According to Morgan and McKenzie (1993), UTI is the second most common condition for the use of antimicrobial treatment in primary and secondary care, and urine samples account for the highest single category of specimens examined in most medical laboratories. A Sample of urine was sent to the laboratory for culture and sensitivity to ensure Sarah hadn’t developed resistance to trimethoprim and change the antimicrobial if necessary (Rigby and Gray, 2005). The author’s conclusion given Sarah’s history, clinical signs and urinalysis with the presence of nitrite and leucocytes, was that of a lower urinary tract infection which should be treated with antibacterial therapy. Before deciding upon appropriate antibacterial therapy the author referred to the Scottish Intercollegiate Guidelines Network (SIGN) (2006) management of suspected bacterial urinary tract infection in adults, which suggests using trimethoprim or nitrofurantoin for 3 days. To make a safe prescribing decision about which antibacterial to use it is important to consider the patients’ present renal and hepatic function. Therefore, the author obtained venous bloods from Sarah. Blood tests ordered from the laboratory were Urea and electrolytes (to check present renal status), liver function tests (to check present hepatic function), C reactive protein and full blood count (to check for evidence of infection). Interpretation of the blood results revealed a raised white cell count and C reactive protein which would suggest evidence of infection (Sanders et al, 2005, p249). All other results were within normal limits. It is important to check Sarah’s renal function prior to treatment with an antibacterial. In renal failure antibacterial’s normally excreted by the kidney accumulate causing toxicity unless the dose is reduced. It is especially true to aminoglycosides which should be used with caution; and nitrofurantoin should be avoided all together (BNF 60, 2010, p364). Sarah’s renal function is within normal limits therefore trimethoprim is considered a safe choice of antimicrobial according to the author. Lanarkshire Area Drug and Therapeutics Committee (2007), indicate that trimethoprim should be used as the first line antibiotic therapy in lower urinary tract infection. It is important to prescribe in accordance with local formularies as they are developed to ensure prescribing decisions are cost effective and evidence based. The author concluded that trimethoprim would be a safe choice of antibacterial as Sarah had received this drug previously with no adverse drug reaction. Although, it is important to note that Sarah has experienced no adverse drug reactions to any medication in the past therefore, other antibacterial’s could have been considered if trimethoprim was unsuitable. 2.5: Applies knowledge of medications in prescribing practice. Trimethoprim is licensed for the use in Urinary tract infection (UTI) and treatment of trimethoprim sensitive organisms including Staphylococcus aureus, Eschersichia coli, proteus and streptococcus (EMC, 2011). Which according to Moore (2005, p249) are the most causative organisms in UTI. Trimethoprim fights these causative organisms by inhibiting the enzyme dihydrofolate reductase and interfering with the folic- folinic acid system (Simonsen et al, 2006, p195). Sarah had been prescribed trimethoprim previously for a lower UTI, which settled her symptoms at that time. However, bacteria can develop some resistance when exposed to the same antibacterial. In addition, it has been reported that there is less resistance to trimethoprim when compared to other sulphonamides (Simonsen et al, 2006, p195). To ensure Sarah was able to receive the recommended dose of trimethoprim, the author had to consider the pharmacokinetics of the drug. Pharmacokinetics deals with a drug’s actions as it moves through the body. Therefore, pharmacokinetics reviews how a drug is absorbed, distributed, metabolised and excreted (Lippincott, Williams and Wilkins, 2005, p12). Different drugs have different physical properties and this can affect the pharmacokinetics (Shargel, Wu-Pong and Yu, 2004, p453). In this context, it is important to consider the bioavailability and half-life of the drug being prescribed. Pharmacokinetic properties of a drug can be found directly from the drug manufacturer which the author accessed online. According to the EMC (2011), trimethoprim is rapidly absorbed from the gastrointestinal tract when taken orally with approximately 40-70% bound to plasma proteins. When a drug is taken orally, a large portion of the drug can be metabolised during first pass metabolism in the liver. This means that a substance could be absorbed into the blood but eliminated before it reaches systemic circulation (Simonsen et al, 2006 pp 53-55). The fraction of the ingested amount of drug that reaches the systemic circulation without being metabolised is a term called bioavailability (Simonsen et al 2006, p 54). Drug excretion can be expressed in terms of half –life, this is the time it takes for the concentration of the drug in the plasma to fall to half of its initial value (Nuttall, Rutt-Howard, 2011). The half- life of trimethoprim is approximately 8 to 10 hours. Peak plasma levels are reached within 1-4 hours with about 40-60% of a dose being excreted unchanged in the urine within 24 hours, with metabolites. This is important when prescribing trimethoprim in patients with renal impairment and elderly as they may require a reduced dose. Conversely, a study carried out by Curkovic et al (2010 p160), to determine the extent of elimination of trimethoprim via haemofiltration in 2 critically ill patients with renal failure concluded that trimethoprim is removed by haemofiltration to a significant degree, and dose reduction in these patients could lead to significant under dosing. It’s the authors understanding that even though this study was small, each patient must be considered on an individual basis when calculating the drug dose required. The author referred to the BNF 60 (2010 p353) to check for contraindications to prescribing trimethoprim for Sarah. The only contraindication noted was blood dyscrasias, which Sarah does not suffer from. However, it was important to note that the manufacturer advises not to use in pregnancy as it causes teratogenic risk in the first trimester. Folic acid is essential to foetal development, especially within the first trimester, and as trimethoprim is a folate antagonist this prevents dividing cells using folic acid, posing significant risk to the developing fetus (Schardein, 2000 p382). This was considered important to the author as Sarah is of child bearing age and this could have changed the prescribing decision had Sarah been pregnant. It is also important that trimethoprim is present in breast milk (BNF 60, 2010 p353), and although Sarah has no children, this would have been taken into consideration during the prescribing process. Taking all these details into consideration, and referring to local and SIGN guidelines, as discussed previously, the author made the decision to prescribe 200mg of trimethoprim, to be taken twice daily, for 3 days until the course is complete. Sarah had received trimethoprim previously with no adverse effects however, it was important to inform her of the undesirable side effects of the drug stated by the manufacturer. These effects include, allergic skin reactions, nausea, vomiting, itching and in more severe cases anaphylaxis and angioedema (EMC, 2011; BNF60, 2010 p353). The author believes it is important for Sarah to be informed of the undesirable effects in order that she can make an informed decision about taking the prescribed medication. 1.5: Is able to use the adverse drug reaction reporting mechanism. When making a prescribing decision it is important to consider the benefit of taking the drug and the risk of not taking it. The more serious adverse effects a drug has, the more important it is to come to a rational decision regarding the prescription in question (Simonsen et al, 2006 p12). The World Health Organisation (WHO) definition of an adverse drug reaction (ADR) has been one used for over 30 years. It is described as “a response to a drug that is noxious and unintended and occurs at doses normally used in man for the prophylaxis, diagnosis or therapy of disease, or for modification of physiological function” as cited by Davies (1999). Sarah disclosed that she had previously received trimethoprim with no adverse or unpleasant effects. However, Informing Sarah of the undesirable effects of the drug as stated by the manufacturer will help her to recognise the signs and symptoms of such effects, this is particularly important when discharging patients into a community setting. Hospital settings allow patients to be monitored closely when a drug is commenced and adverse effects can be recorded and treated appropriately. In a community setting, observation is reduced, therefore the importance of recognising adverse effects must be discussed with the patient so they can identify them quickly and stop the medication to prevent further harmful effects and possible hospitalisation (Simonsen et al, 2006 p12). A report published by Boseley (2008), estimated that the NHS spend almost £2 billion a year treating patients who have had an adverse drug reaction and that 6.5% of hospital admissions in 2006 were as a result of an ADR, this equates to over one million patients. This figure is alarming and reiterates the importance of discussing the undesirable and potentially life threatening side effects of the prescribed medicine with the patient and how to report such effects. Risk reduction and prevention should be the priority of any prescriber, with this in mind the author referred to the BNF to ensure the benefits of using trimethoprim outweighed the risks involved with taking the medication. Some drugs are closely monitored due to the risk of an adverse drug reaction, this is particularly true of newly licensed drugs which are denoted by an inverted black triangle in the BNF. Although all drugs undergo clinical trials, the test group tends to be small, and ADRs can be missed during the clinical trial period. Therefore, importance has been placed on the post marketing data collection of ADRs. This can be done in the UK using the yellow card scheme (Nuttall and Rutt-Howard, 2011 p189). The yellow card scheme can be found at the back of the BNF or online at the Medicines and Healthcare products Regulatory Agency (MHRA) website. It is important that practitioners and patients report any potential ADR and send the information to the MHRA, so they can process and disseminate the information gathered. Any ADR related to a black triangle drug must be reported regardless of severity (Nuttall and Rutt-Howard, 2011 p189). Even though trimethoprim is not a black triangle drug in the BNF, it is important to understand what the black triangle symbol means and also the process involved in reporting an ADR to the MHRA to help prevent further complications in patients. Trimethoprim is an established drug. However, if the patient experienced a serious drug reaction then it should be reported to the MHRA. Serious drug reactions are those which are fatal, life threatening, disabling, incapacitating, medically significant or have resulted in hospitalisation or prolonged hospitalisation (Medicines and Healthcare Products Regulatory Agency, 2008). 2.8: Understands how drugs are licensed and monitored. As previously discussed, the MHRA must be informed of any adverse drug reaction to prevent potential and further complications. The MHRA is the government agency responsible for ensuring that medicines and medical devices work, and are safe for the public (MHRA, 2008). The MHRA ensure that medicines are thoroughly trialled on thousands of people and meet rigorous standards before they are licensed. A license from the MHRA is required before any medicine can be used to treat people in the UK. No product can be 100% safe as all products have side effects. However, the MHRAs main aim is to safeguard the public and they have to consider the likely effects of taking the drug in relation to the risk to the patient. If the agency believes that the medicine does not meet these standards, they have the power to withdraw the product from the market, suspend production and prosecute a manufacturer or distributor if a law has been broken (MHRA, 2008). Trimethoprim has been licensed to treat urinary tract infections since 1969, and according to a study carried out by Jick and Derby (1995), it is a safe drug to use and drug reactions are very rare. The author acknowledges the study is fifteen years old, but also realises that trimethoprim was available for over 25 years prior to the study being conducted. To begin the process, companies must apply for permission to test drugs through clinical trials and the MHRA must be satisfied that they have met strict safety criteria. Results from the trials are then sent to the MHRA for detailed assessment. Once the MHRA is satisfied that the medicine works as it should and is acceptably safe, it is given a product license (MHRA, 2008). New chemicals and vaccines are put on probation for up to 2 years and labelled with a black triangle to ensure prescribers are aware of the need to monitor them carefully. The black triangle is not removed until the MHRA is satisfied the drug works safely in large numbers of people (MHRA,2008). As discussed previously, trimethoprim does not have a black triangle and has been available for use since 1969. The author believes the risks of using trimethoprim would be much smaller than using a new drug to the market with the black triangle attached and recognises the importance of looking for the black triangle when making a prescribing decision. 3.4: Writes and maintains coherent records of prescribing practice The Nursing and Midwifery council (NMC) (2009), state that good record keeping is essential to the provision of safe and effective care and is not an optional extra to be fitted in if circumstances allow. Good records help to improve accountability and address complaints and legal processes. The NMC recognise that the way in which nurses and midwives keep records is usually set by their employer, and this is undoubtedly the case for the author. The record kept for Sarah was an integrated care pathway, used within NHS Lanarkshire that supports the record keeping guidance set by the NMC (2009). The care pathway is a vital piece of documentation, made available to all members of the prescribing team, and shows how the author made the clinical judgement and decision to prescribe trimethoprim for Sarah based on the assessment described earlier in this case study. Non-medical prescribers are responsible for the decisions they make. Therefore, it is important that they ascertain a diagnosis before prescribing any medication (NMC, 2006). The care pathway was written at the same time as the assessment with details of the presenting complaint, past medical history, drug history including drug allergies, detailed clinical examination, diagnosis of lower UTI and the dose and frequency of trimethoprim prescribed, date, time and the authors’ designation as an ANP and non- medical prescriber. It is important to document this information as it promotes safe continuity of care, especially when discharging into the community. In addition to the care pathway, a discharge document was completed in order to obtain a prescription from the hospital pharmacy and documentation for Sarah’s GP. She was advised to take the discharge document with details of the prescription to her GP and arrange a follow up appointment. Providing Sarah’s GP with a copy of the discharge document is vitally important for safe continuity of care (SEHD ,2002). To ensure legal validity, the discharge document includes details of Sarah’s reason for attending hospital, discharge diagnosis, date and time of attendance, name, formulation and quantity of drug prescribed including any follow up arranged by the hospital and the prescribers details. (Courtenay, 2001, p17). This information should help make continuity of care and communication better and if Sarah does not respond to the trimethoprim prescribed then her GP can reassess her, identify potential on-going problems and make a further prescribing decision based on the information he has been presented with.