Side-effects of specific drug classes (for elderly)

There are a number of differences between older people and younger people that have an impact on their treatment with medicines. These are particularly apparent in very old patients:

• Older people's bodies take up and eliminate medicines from the body differently than younger patients'.
• Older people are susceptible to a wide range of diseases, including Alzheimer's disease, heart disease, bone diseases and mental illnesses.
• Older people often have more than one disease at a time, making it difficult to treat the separate diseases.
• Older people may be weaker than younger patients, making them vulnerable to disease and the risks associated with medical treatment.

Side-effects of specific drug classes:

NSAIDs

• Gastrointestinal bleeding is more common and has more serious consequences in older patients.
• NSAIDs can worsen heart failure or aggravate impaired renal function. These effects can be worse in elderly patients.
• They are best avoided, if possible, for simple pain relief in osteoarthritis (OA), etc; paracetamol should be tried instead and, if this is insufficient, try a low-dose NSAID in addition, with proton-pump inhibitor (PPI) or misoprostol cover, or substitute a low-dose opioid.
• Consider complementary therapies such as acupuncture to help with pain management.
• The co-prescription of NSAIDs and ACE inhibitors in older patients can be a recipe for disaster; their combined deleterious effect on renal cortical perfusion and function can lead to significant renal impairment in the older patient.

Hypnotics

• Hypnotics with long half-lives are a significant problem and can cause daytime drowsiness, unsteadiness from impaired balance and confusion.
• Short-acting ones may also be a problem and should only be used for short periods if essential.
• In patients prone to falls or dizziness avoid using these agents unless absolutely necessary.
• Where benzodiazepines are used to help patients overcome a crisis or transitional period, great care must be taken that they be given only for short periods, to avoid the danger of dependence and addiction.
• It is much better to take a good history of an older patient's sleep habits and suggest sleep hygiene and non-pharmaceutical measures to overcome insomnia, than to prescribe drugs, which at best will be a temporary solution.

Diuretics

• This class of drugs is often overused in the elderly and should not be used for chronic treatment of gravitational oedema where measures such as leg-raising, increased walking/leg exercises and graduated compression stockings are often sufficient.
• Where diuretics are used to treat hypertension or cardiac failure, they should be reviewed regularly, along with an assessment of the patient's state of hydration and U&Es if necessary.
• Withdrawal of diuretics requires careful monitoring and consideration of potential contra-indications to withdrawal and can be difficult to achieve. For example, patients with well-controlled heart failure can develop troublesome symptoms and blood pressure can rise significantly in hypertensive patients.

Digoxin

In the very elderly, the daily maintenance dose should be 125 micrograms. In the renally impaired, the dose should be 62.5 micrograms. 250 micrograms/day are likely to cause toxicity.

Drugs that cause bone marrow suppression

Drugs such as co-trimoxazole and chloramphenicol should only be used if there is no suitable alternative.

Anticoagulants and antiplatelet drugs

• Beware of gastrointestinal bleeding and contra-indications such as peptic ulceration which may have occurred a long time ago and been forgotten about.
• For warfarin, prescribe only when patients have a full understanding of why the drug is being taken, its dangers, correct daily dosing/timing and the importance of regular INR monitoring.

Antidepressants

• Tricyclic antidepressants commonly cause postural hypotension and confusion in the older patient; they should be used carefully.
• Serotonergic medications used for depression may cause serotonin syndrome and agitation in the older patient; this can be difficult to distinguish from some of the symptoms of depression.

Diabetic medication

• Long-acting oral hypoglycaemics such as chlorpropamide and glibenclamide should be avoided as there is a significant risk of hypoglycaemia when these agents are used in the older patient.
• Tight diabetic control must be balanced against potentially catastrophic events precipitated by hypoglycaemia, particularly in those who live alone, have a poor understanding of diabetes self-management, or who experience few warning symptoms of hypoglycaemia.