Fluid balance – the 3 Ds
Many patients with AL amyloidosis should limit their fluid intake
This advice is extremely important, but is often overlooked.
Patients receiving chemotherapy for other conditions that are not AL amyloidosis are often told to “drink plenty” to avoid dehydration. But in AL amyloidosis, this well-meaning advice is inappropriate and can prove dangerous.
Many patients with AL amyloidosis have amyloid deposits in the kidneys and/or in the heart. These two problems mean that the body is unable to cope well with excess fluids. The combination of kidneys that are unable to sufficiently clear the fluid into the urine and a heart that is too stiff to pump efficiently may be problematic. Even if just one of these organs is affected by amyloidosis, excess fluids can make matters worse.
Patients with fluid overload may develop swelling in the legs (oedema) or difficulty breathing due to heart failure.
The ALchemy (AL amyloidosis chemotherapy) study is a large, on-going, “real world” study of chemotherapy in AL amyloidosis, started at the NAC in 2009 and funded by a grant from the charity Myeloma UK. In this study, fluid overload has been clearly identified as the number 1 serious side effect experienced by patients with AL amyloidosis. It is far more common than infection, neuropathy or any other severe side effects reported. Fluid overload comprised nearly 40% of all the episodes of toxicity. Nearly 1 in 3 of the patients who were hospitalised because of toxicity had fluid overload.
Fluid excess can be avoided by careful attention to the 3 Ds:
3. Daily weights
Fluid intake should be steady and should usually not exceed 1.5 litres per day
Salt intake should be limited. This includes attention not just to salt added to the food from the salt pot, but also to food with high salt content such as crisps, bacon, canned meats, sausages, canned soups and smoked fish. It can be very helpful to meet with a dietician for precise and personalised dietary advice.
Doctors will often prescribe diuretics (water tablets) which increase the amount of urine produced and help the body to lose excess salt and water in the urine. This can help to reduce ankle swelling and breathlessness. Diuretics prescribed may include furosemide and spironolactone. Taking these drugs is not a substitute for avoidance of excessive dietary salt and water.
Patients should follow their doctor’s advice carefully regarding the dose of diuretic and the time of day when the tablet should be taken.
3. Daily weights:
Some patients benefit from recording their weight regularly, usually daily or weekly. It is important that weight should be measured consistently- using the same scales, at the same time of day. This is usually best done first thing in the morning after passing urine, just wearing underclothes. Several litres of fluid can accumulate in the body without it being very noticeable. An increase in weight can be an early sign of fluid excess. The doctor or nurse can then recommend appropriate measures such as increased diuretic dose, before the patient even feels unwell because of the fluid overload.
Careful control of high blood pressure is important in patients with amyloid deposits affecting the kidneys. However, certain blood pressure drugs should be avoided if there is amyloid affecting the heart. The drugs which are most commonly used in heart failure due to other causes may actually lead to a worsening of heart failure due to amyloidosis.
In patients with low blood pressure, drugs such as fludrocortisone or midodrine may help to maintain blood pressure and allow higher diuretic doses.
Some patients may experience light-headedness, fatigue on minimal exertion or fainting due to drops in blood pressure. They may benefit from instruction in how to change position carefully from lying to sitting, sitting to standing and standing to walking.
Special medication considerations
Many standard heart failure medications reduce the already low blood pressure in patients with cardiac amyloidosis and can actually worsen the symptoms. the following drugs should be used with caution:
- calcium channel blocker drugs
- angiotensin converting enzyme (ACE) inhibitor
- angiotensin receptor blockers
- beta blockers
Under certain circumstances some other treatments may be helpful. For example:
- Alpha agonist blocker drugs such as midodrine may help to maintain blood pressure and allow higher diuretic doses.
- In some cases anticoagulation (warfarin) may be recommended.
- Pacemakers may be recommended if there is a slow or irregular heart rate.
Symptoms of peripheral neuropathy: Medications that may help to alleviate neuropathic pain include amitryptiline, gabapentin, pregabalin and duloxetine. Medical staff can give advice regarding appropriate foot care and footwear. This is important in order to prevent painless ulcers at pressure points and to protect areas of the foot that lack sensation.
Symptoms of autonomic neuropathy: If there is orthostatic hypotension, elastic stockings may be recommended. Drug treatment with midodrine may also be helpful. Care should be taken to avoid dehydration if there is vomiting and diarrhoea. Intravenous fluids and anti‑nausea drugs may be necessary. There are drugs that can help to control diarrhoea and constipation, and others that can help to combat erectile dysfunction. If there are disturbances of heart rhythm, drug therapy or implantation of a pacemaker may be necessary.
It is very important that patients tell their doctors about any other drugs they may be taking, including complementary or alternative medications or supplements before starting treatment for AL amyloidosis. Some drugs may interact inside the body and lead either to toxicity due to raised drug levels, or lack of effect due to reduced drug levels. It is vital that the doctors prescribing drugs for AL amyloidosis have full access to all information regarding other medications, in order to avoid these problems.
If patients who are taking chemotherapy for AL amyloidosis become ill or require any treatment for a different condition or surgery it is important to inform the treating doctors and the NAC doctors, so that care can be co-ordinated.
Surgery and anaesthesia
It is generally advisable for patients with AL amyloidosis to avoid undergoing surgery, anaesthesia and other invasive procedures.
If such procedures are necessary, patients should request that the surgeons, anaesthetists and other doctors involved contact the NAC doctors beforehand, to discuss any special considerations involved. For example, it is very important that great care is taken to monitor and maintain blood pressure and fluid balance throughout such procedures. Care should also be taken because of the tendency of tissues with amyloid in them to bleed and to heal poorly.
Pregnancy and fertility
Thalidomide, one of the drugs sometimes used to treat AL amyloidosis, is well known to be particularly harmful to a developing foetus. Before the regulatory authorities allowed thalidomide to be licensed for its current uses, very strict conditions were instituted for prescription of this drug, to ensure that there is no chance that it is taken by a pregnant woman. The drug even reaches the sperm in men, so men taking thalidomide must use condoms at all times, if having intercourse with a woman who could become pregnant. All patients taking this drug must follow the regulatory guidelines for prescription of thalidomide.
Many of the other drugs used to treat AL amyloidosis are also dangerous during pregnancy, so women of child-bearing age should use contraception during treatment.
Many of the drugs used to treat AL amyloidosis may damage fertility. Both men and women of child-bearing age should consider options for freezing sperm or eggs before starting these treatments. Doctors at the NAC can refer patients for appropriate counselling regarding these possibilities.