Older people are more likely to be prescribed medication than younger people; however, unfortunately medication is not always prescribed appropriately, and age-related changes increase a person's vulnerability to adverse effects. According to the World Health Organization (WHO, 2022):
‘Rational use of medicines requires that patients receive medications appropriate to their clinical needs, in doses that meet their own individual requirements, for an adequate period of time, and at the lowest cost to them and their community.’
Irrational use of medicines is a major problem worldwide. The WHO estimates that more than half of all medicines are prescribed, dispensed or sold inappropriately, and that half of all patients fail to take them correctly. The over-use, under-use or misuse of medicines results in wastage of scarce resources and widespread health hazards.
Age-related changes and adverse medication effects
Older adults (people aged 65 or over) and those ethnic minority and low-income communities are under-represented in clinical trials. This means that prescribers have limited information about the efficacy of a drug and any side effects in these groups (Fisher et al, 2022).
Drugs given orally are normally absorbed in the small intestine, metabolised in the liver and excreted by the kidneys (Garza et, al, 2022). Age-related changes affect the ability to absorb and excrete drugs. Ageing affects the rate of stomach emptying and the speed with which food and medicines travel through the gastrointestinal tract. Blood flow is also reduced, affecting the absorption of medication (Dumic et al, 2019). Ageing leads to a decline in muscle mass and an increase in fat, which has an impact on the way medicines are absorbed (Distefano and Goodpaster, 2018). The size of the liver reduces by 20% in older age and blood flow to the liver is reduced by 40%, these changes reduce the ability to metabolise drugs (Kim et al, 2015).
Renal function declines with age and decline in renal function can impair the ability to excrete medication (Sönnerstam et al, 2016). Age-related changes at molecular level can alter the way drugs bind to specific receptors, and this can increase or decrease the effect of a medicine in an older person (Davies et al, 2020). Age-related changes affect the way an older person's body reacts to medication, and a medicine that was suitable for a person when younger may be inappropriate as the person ages. Older people and their families can find this difficult to understand and can resist changes to medication,
Age-related changes increase the risk of a person suffering adverse drug reactions (ADRs). Adverse drug reactions are ‘unintended, harmful events attributed to the use of medicines’ (Coleman and Pontefract, 2016). ADRs can have a major effect on a person's health and quality of life. The following case study outlines a medication review of a patient admitted to an inpatient ward caring for older people. We were able to check previous medical history, test results and medication history on our electronic patient record
‘Despite health professionals' awareness of the risks associated with polypharmacy and sedative use in older people, inappropriate prescribing still occurs’
Case history
Mr Jones (a pseudonym) is an 83-year-old Caucasian male. His medical records indicate that he has prostatic hypertrophy, atrial fibrillation and bipolar affective disease in remission. He has had two falls since admission to the ward (Table 1 provides details of his medication and indications) and was admitted originally for depression.
Table 1. Medication and indications
| Medication | Dose | Frequency | Indication | Comments |
|---|---|---|---|---|
| Tamsulosin | 400 microgram modified-release capsules | One daily | Prostatic hypertrophy | Drops blood pressure, give at night |
| Finasteride tablets | 5 mg | One daily | Prostatic hypertrophy | |
| Chewable vitamin tablets | 500 mg/400 unit | One daily | Not indicatedLow calcium? | Calcium can cause dyspepsia |
| Antacid liquid peppermint | 10 ml | Three times daily as required | Dyspepsia | Calcium can cause dyspepsia |
| Lansoprazole gastro-resistant capsules | 15 mg | One daily | No indication peptic ulceration or gastro-oesophageal reflux | Calcium can cause dyspepsia |
| Lactulose oral solution | 15 ml | Twice daily | Constipation | Calcium can cause constipation |
| Quetiapine modified release | 50 mg | Each night | Antipsychotic to treat bipolar disease | Increases risk of falls |
| Simvastatin | 40 mg | Each night | Elevated cholesterol | |
| Felodipine modified release | 10 mg | One daily | Hypertension | |
| Buspirone | 5 mg | Twice daily | Generalised anxiety disorder | |
| Mirtazapine orodispersible tablets | 45 mg | One daily | Depression | Can cause sedation |
| Zopiclone | 3.75 mg | Each night as required | New prescription | |
| Promethazine hydrochloride tablets | 25 mg | One each night | Long-acting antihistamine used as night sedation | |
| Promethazine hydrochloride | 25 mg | Each night as required | New prescription |
Initially, there was some reluctance from the ward consultant for the pharmacist and consultant nurse to conduct medication reviews. The consultant was responsible for patient care on the ward and may have considered that the reviews would infringe on the medical domain. However, it was agreed that the recommendations would be considered. Table 2 outlines the rationale for these.
Table 2. Medication changes and rationale
| Medication | Issue | Recommendation and rationale |
|---|---|---|
| Zopiclone 3.75 mg once each night as required | New sedatives should not be initiated in hospital as they increase risk of falls and factures. Patient has fallen twice since admission | New prescription on admission Discontinue |
| Promethazine hydrochloride tablets 25 mg one at night | This long-acting antihistamine can cause daytime sedation and increase the risk of falls | Discontinue |
| Promethazine hydrochloride tablets 25 mg one at night as required | Dose of long-acting antihistamine doubled on admission. Increased risk of daytime sedation and falls | Only as a last resortUse sleep hygiene measures |
| Chewable vitamin tablets 500 mg/400 unit one daily | It was considered that this was causing dyspepsia and possibly constipation | DiscontinueIf calcium required in the future prescribe calcium citrate better tolerated in older people |
| Lansoprazole gastro-resistant capsules 15 mg one daily | Multiple risks with long-term use. It is thought this might have been given because calcium carbonate was causing dyspepsia | Discontinue |
| Antacid liquid peppermint 10 ml three times daily as required | Not indicated for long-term use | For review in 1 week |
| Lactulose oral solution 15 ml twice a day | Unclear if required, monitor bowel actions using Bristol stool chart | For review in 1 week |
The review identified medications with three effects that needed consideration: drugs with sedative properties; drugs with the potential to cause hypotension; and medication affecting the gastrointestinal tract.
Medication with sedative properties
Mr Jones had suffered two falls in the inpatient unit. These affected his confidence and he required persuasion to remain active, especially after the second fall. The pharmacist and consultant nurse (review team) noted the new prescription of zopiclone and the increase in promethazine. Evidence-based guidance states that prescribers should not normally initiate new sedatives in hospital (O'Mahoney et al, 2015: Curtin et al, 2021). Z-drugs, such as zopiclone, increase risk of falls, and all sedatives and hypnotics increase fracture risk in older people (Anrade, 2018: Ryba and Rainess, 2020). The review team recommended that the as required zopiclone and the regular promethazine were discontinued. The as required promethazine could be retained, but nursing staff were encouraged to promote sleep hygiene and to use this a last resort. The consultant agreed to implement the recommended changes.
Medication that can cause hypotension
The review team asked nursing staff to check lying and standing blood pressure to establish whether Mr Jones had a postural drop. This was not noted, although he did complain of dizziness and said he moved around less than he used to because of this. The review team considered the increased risks secondary to the use of tamsulosin and quetiapine. It recommended that tamsulosin was prescribed at night to reduce the risks of hypotension.
Medication affecting the gastrointestinal tract
Mr Jones was taking 500 mg/400 unit chewable vitamin tablets, comprising a combination of calcium carbonate and vitamin D. The indication for this was unclear. Some individuals who take calcium supplements experience gastrointestinal side effects, including dyspepsia, bloating and constipation. Calcium carbonate appears to cause more of these side effects than calcium citrate, especially in older adults who have lower levels of stomach acid. Symptoms can be alleviated by changing to a different type of calcium, taking smaller calcium doses more often during the day, or taking the supplement with meals (National Institute for Health and Care Excellence (NICE), 2023). We checked all blood results and they were normal. There were some age-related changes to renal function.
The team could find no record of an indication for the use of lansoprazole, a proton pump inhibitor (PPI). Mr Jones reported a history of dyspepsia of several years' duration. NICE (2023) guidance recommends that if there is an endoscopy confirmed diagnosis of gastro-oesophageal reflux disease (GORD), a PPI should be offered for 4 or 8 weeks.
‘The review team recommended that the as required zopiclone and the regular promethazine were discontinued. The as required promethazine could be retained, but nursing staff were encouraged to promote sleep hygiene and to use this a last resort’
There is growing evidence of the adverse effects of PPIs, especially in older people. These include hypomagnesia, interstitial nephritis, fractures and Clostridium difficile-associated diarrhoea (Pezeshkian and Conway, 2018). Older adults are also at increased risk of pneumonia, B12 deficiency and dementia, and it is important to review the need for PPI treatment, especially in older people (Maes et al, 2017). Prescribers should ensure that PPIs are prescribed for recognised indications and appropriate durations to minimise PPI over-use and the associated increased risk of harm (All Wales, Medicines Strategy Group, 2018).
The team noted that Mr Jones was prescribed an antacid. NICE (2023) advises that this is not used long term; therefore, it was recommended that the medications affecting the gastrointestinal system were addressed at the same time. It was recommended that the 500 mg/400 unit chewable tablets were discontinued, and for Mr Jones to commence vitamin D supplements. The NHS (NHS, 2023) advises 10 micrograms a day for older people who are housebound. The review team recommended that the omeprazole was discontinued and that nursing staff commence monitoring bowel actions using the Bristol stool chart. This would be reviewed in 7 days (Nazarko, 2017). It was agreed to review the antacid in 7 days. The consultant accepted all of the recommendations.
Conclusion
Despite health professionals' awareness of the risks associated with polypharmacy and sedative use in older people, inappropriate prescribing still occurs. Some junior doctors can get into the habit of prescribing sedatives such as Z-drugs ‘just in case’. This practice can cause catastrophic harm to vulnerable individuals.
Sometimes a medication such as a PPI is prescribed without an awareness of the long-term adverse effects. As the evidence base grows, we may learn that a medication that appeared not to have side effects can be harmful in certain circumstances. All prescribers need to be alert to the dangers of polypharmacy and to review medication. The number of older people who are vulnerable to the adverse effects of medication is set to grow in line with an ageing population with multiple comorbidities.
Key Points
- Ageing affects the ability to absorb and excrete medicines
- Older adults are especially vulnerable to the adverse effects of medication
- The number of older adults prescribed five or more medications has quadrupled in the last 20 years
- Whilst clinicians are happy to initiate medication there is less appetite to review
- Ensuring the older person is only taking medicines that are clinically indicated reduces adverse effects and enhances quality of life
CPD reflective questions
- Why do you think the number of people prescribed five or more medicines has quadrupled?
- Ageing and hospital admission can affect quality of sleep. What measures, other than medication, could be introduced in a hospital ward to promote sleep?
- Medication review can reduce the risk of falls and adverse medication. How can you incorporate medication review into your day-to-day practice?
- Why do you think clinicians are reluctant to review medication? How can we overcome these barriers?