Furosemide 40 mg and 100 mg Tablets

Furosemide is a well-established loop diuretic, prescribed to help the kidneys remove excess salt and water from the body. We supply furosemide as oral tablets in two strengths, 40 mg and 100 mg, with several quantities available to match different prescribed treatment plans.

Furosemide tablets at a glance

Furosemide works by acting on the kidneys to increase the amount of salt and water passed in the urine, which lowers the volume of fluid circulating in the body. This makes it useful for oedema linked to heart, liver, or kidney conditions and for hypertension, although other antihypertensive medicines are often preferred for routine blood-pressure management. Its effect usually begins within an hour of an oral dose and lasts for around six hours, which is why many people notice increased urination during that window rather than throughout the day.

We stock 40 mg tablets in quantities of 180, 270, or 360 and 100 mg tablets in quantities of 60, 90, 120, 180, 270, or 360. The strength and quantity selected should reflect the treatment plan provided by a prescriber; pack size does not determine the dose or length of treatment. If a doctor has specifically prescribed the branded version, we also list Lasix, which contains the same active ingredient, furosemide.

Furosemide is often taken once daily in the morning, although some people are instructed to take it twice daily, usually in the morning and around lunchtime. Follow the directions on the dispensing label rather than adjusting the dose according to swelling or urine output. If a dose is missed, follow the patient leaflet or ask a pharmacist; do not take two doses together to make up for it.

Who furosemide tablets are suitable for

Furosemide is generally used by adults being treated for oedema or hypertension under medical guidance, and dosing information is provided with the medicine. A few groups need particular care. Furosemide is a sulfonamide derivative, so anyone with a known sulfonamide allergy should check this history with a pharmacist before starting treatment. People with diabetes should be aware that furosemide can reduce glucose tolerance and occasionally reveal previously undiagnosed diabetes, so blood glucose may need closer monitoring. Furosemide should not be used in pregnancy unless a doctor judges it clearly necessary, since it crosses the placenta and can affect fetal fluid balance, and it should not be taken while breastfeeding, as it passes into breast milk and can reduce milk supply.

Furosemide must not be taken by people who cannot produce urine, are severely dehydrated or have a markedly reduced circulating blood volume, have severe low sodium or potassium levels, or are in a pre-comatose or comatose state associated with hepatic encephalopathy. Anyone who may fall into one of these groups should obtain medical advice before taking a dose. Because the tablets can occasionally cause dizziness or a drop in blood pressure, especially after the first dose or a dose change, care is also needed before driving or using machinery. Children may be prescribed furosemide, but paediatric dosing is calculated by body weight and has a low daily ceiling, so the 40 mg and 100 mg strengths we sell are usually intended for adult use rather than for children.

Before you start taking furosemide

Before the first dose, confirm a few practical points with a doctor or pharmacist. Kidney function and blood electrolytes, particularly potassium and sodium, are usually checked before and periodically during treatment, since furosemide can lower potassium levels and, less commonly, other electrolytes. It is also useful to review other medicines being taken, because furosemide can interact with certain blood-pressure medicines, lithium, some antibiotics such as aminoglycosides, NSAIDs, and digoxin, among others. Furosemide tablets can be taken with or without food; taking them earlier in the day, rather than close to bedtime, helps avoid night-time trips to the toilet.

Increased urination is expected, but excessive thirst, a very dry mouth, severe weakness, confusion, muscle cramps, fainting, an irregular heartbeat, or a marked reduction in urine output can indicate dehydration, low blood pressure, an electrolyte disturbance, or worsening kidney function. Seek prompt medical advice if these occur. Urgent help is also appropriate for a severe rash, facial or throat swelling, breathing difficulty, or sudden hearing changes.

Handling and storing your tablets

Store furosemide tablets correctly between doses. Keep them in their original container, tightly closed, at 20°C to 25°C and protected from direct light, bathroom humidity, and kitchen steam. As with any medicine, keep the pack out of the sight and reach of children. Avoid transferring tablets into unlabelled containers, since this makes it harder to check the strength and expiry date at a glance.

Ordering and delivery with us

Furosemide is classified as a prescription-only medicine in the United Kingdom, and we always recommend discussing it with a doctor or pharmacist before starting or changing treatment. Our ordering process does not require you to upload a prescription to place an order, so checkout is quick once you have chosen a strength and quantity. When your tablets arrive, check the product name, strength, quantity, expiry date, and dispensing label against what you expect. Keep the patient information leaflet, since licensing and packaging details can vary between brands and should be confirmed against the exact pack received.

Do not use tablets if the container or seal appears damaged, the label is unclear, or the tablets look different from the description supplied with the pack. Keep the parcel and its contents together while you contact our support team so that we can help check the order. Do not combine tablets from different packs unless a pharmacist has confirmed that the active ingredient, strength, and directions are the same.

We have been supplying medicines online since 2017, and our support team is available every day of the week by email, live chat, or phone, with a pharmacist on hand to answer practical questions about your order. Parcels are packed securely and dispatched in plain, unbranded packaging with no medicine labels visible on the outside, then delivered directly to your address in the United Kingdom. If furosemide is one part of a wider treatment plan, our Diuretics range may also be worth a look for related options your prescriber has discussed with you.