My mother has lost a lot of weight: should her medication be reviewed?
Unintentional weight loss in an older person deserves a GP visit, and a medication review should be part of it: some medicines reduce appetite and others are dosed according to body weight.
In short
- Losing 5% of body weight or more over 6 to 12 months without trying is a reason to see the GP.
- Many medicines that older people commonly take can reduce appetite, change taste, cause a dry mouth or cause nausea.
- Some doses also depend on body weight or kidney function, so weight loss may mean they need adjusting.
- Never stop a medicine on your own: record the weight, bring the complete medication list and ask for a review.
Yes, the medication should be reviewed. When an older person loses weight without trying, the doctor needs to look for the cause, and medicines are one of the first things to check: they may be contributing to the weight loss and, at the same time, may need adjusting because the body has changed.
Here we explain when to worry, which medicines can play a part, why weight matters for some doses and how to prepare for the appointment.
| What will you find in this article? |
When is weight loss in an older person a concern?
Losing 5% of body weight or more over 6 to 12 months without trying is considered significant. This is the criterion used by the journal American Family Physician for people over 65, and MedlinePlus summarises it as losing 4.5 kg or 5% of usual weight in that period with no known cause.
This weight loss is linked to more complications and higher mortality, so it is best not to wait and see whether it recovers on its own. To give you an idea of the numbers:
| Usual weight | 5% loss | Weight at which to see the GP |
|---|---|---|
| 55 kg | 2.75 kg | About 52 kg |
| 60 kg | 3 kg | 57 kg |
| 70 kg | 3.5 kg | About 66.5 kg |
| 80 kg | 4 kg | 76 kg |
Other clues also count: clothes or rings that have become loose, dentures that move, plates that come back almost full or less interest in cooking.
Can medicines cause weight loss?
Yes. Several medicines commonly used by older people can reduce appetite, change the taste of food, cause a dry mouth, make swallowing harder or cause nausea. Taking many medicines adds these effects together, and the American Family Physician review stresses that they should not be overlooked as a cause.
| How they affect eating | Examples of medicines cited |
|---|---|
| Change taste or smell | Allopurinol, ACE inhibitors (such as enalapril), antihistamines, levodopa, spironolactone |
| Reduce appetite | Benzodiazepines, digoxin, metformin, opioids, SSRIs (a type of antidepressant), antiepileptics |
| Cause a dry mouth | Anticholinergics, antihistamines, loop diuretics |
| Make swallowing harder or irritate the oesophagus | Bisphosphonates, iron, potassium, NSAIDs, doxycycline |
| Cause nausea | Digoxin, metformin, SSRIs, statins, bisphosphonates |
A medicine appearing in this table does not mean it is to blame, or that it should be stopped: many are essential. It means the doctor or pharmacist should assess it in the context of the whole treatment. To learn more about the risks of taking many medicines at once, read our guide to polypharmacy in older people.
Why should doses be reviewed after weight loss?
Because some doses are worked out taking body weight, age or kidney function into account. If the person loses weight, a dose that used to be right may no longer be. That is why the doctor may order a blood test and review the treatment even when the medicines are not causing the weight loss.
- Anticoagulants: the apixaban summary of product characteristics, for example, provides for a reduced dose in atrial fibrillation when at least two of these conditions apply: aged 80 or over, weighing 60 kg or less and a raised creatinine level. More in our article on anticoagulants.
- Digoxin: its dose is tailored to age, weight and kidney function, and loss of appetite, nausea or vomiting can be early signs of too much digoxin in the blood, according to the Spanish Society of Hospital Pharmacy.
- Diabetes medicines: eating less after taking insulin or other diabetes medicines is a common cause of low blood sugar, according to MedlinePlus.
What matters is that the healthcare team knows about the weight loss: it is information that changes decisions.
What other causes need to be ruled out?
Medicines are only one possible cause. The doctor will also consider depression, swallowing problems, the state of the mouth and dentures, cognitive decline, thyroid problems, digestive conditions and other illnesses that need investigating.
Social factors play a part too: living alone, being unable to go shopping, having little money or following very restrictive diets without supervision. So it helps to describe their daily life at the appointment, not just their symptoms. Our article on eating well for older people who take many medicines has ideas for improving meals.
A practical example: Rosa has lost 4 kilos in five months
Let us take the case of Rosa, aged 84, who lives alone and takes 8 medicines a day. Her daughter notices that her skirt has become loose and weighs her: she has gone from 62 to 58 kg in about five months, more than 6%. Rosa says food "tastes odd" and that she sometimes skips dinner.
This is what her daughter can do:
- Weigh her once a week, on the same scales and at the same time of day, and write it down.
- Gather all the medicines she takes, including those bought without a prescription and any supplements, and make a list with doses and times.
- Book an appointment with her GP and explain the weight loss, the poor appetite and the change in taste.
- Ask whether any medicine could be contributing and whether any dose needs adjusting or a blood test is needed.
- Tell the pharmacist about any changes, so the pill organiser or multi dose pack is updated the same day.
What she should not do is stop the medicine she suspects on her own: some cannot be stopped suddenly.
How can IMA Health help you?
If your mother takes several medicines, at IMA Health we coordinate with a specialised pharmacy so her medication is prepared by day and time of each dose, we deliver it to her home and we provide personalised follow-up. When the doctor adjusts a dose or stops a medicine, the pharmacy prepares the next doses with the change, which lowers the risk of carrying on with the old regimen.
Sources
- American Family Physician: Unintentional Weight Loss in Older Adults (Gaddey and Holder, 2021)
- MedlinePlus: unexplained weight loss (Spanish version)
- CIMA, Spanish Medicines Agency (AEMPS): apixaban 5 mg summary of product characteristics (section 4.2, in Spanish)
- Spanish Society of Hospital Pharmacy (SEFH), pharmacokinetics group: clinical case bulletin no. 15, digoxin toxicity (in Spanish)
- MedlinePlus: low blood sugar, self care (Spanish version)
This article is for information only and does not replace advice from your doctor or pharmacist.