Losartan Side Effects

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Answer the side-effect intent for losartan without diagnosing; distinguish common from serious reactions and give safe next-step/reporting guidance.

What is losartan?

Losartan contains the active ingredient Losartan potassium.

• Active ingredient — Losartan potassium
• Registration number — A40/7.1.3/0069
• Registration holder — Biotech Laboratories (Pty) Ltd

It is approved for:

• To treat a condition known as hypertension or high blood pressure; or
• To protect the kidneys in type 2 diabetic patients with protein in their urine (proteinuria)

Common side effects of losartan

Not everyone gets side effects. The effects below are those listed in the South African approved leaflet, grouped using the leaflet’s own frequency wording.

Frequent side effects

• Flu-like symptoms
• Decrease in the haemoglobin (substance in red blood cells that makes it possible for blood to carry oxygen throughout the body) concentrations characterised by tiredness, dizziness, feeling cold, pale skin, trouble breathing, headache and weakness
• High potassium levels in your blood characterised by abdominal pain, chest pain, a fast or irregular heartbeat, muscle weakness or numbness in the limbs, nausea, vomiting and diarrhoea (hyperkalaemia)
• Headache
• Dizziness
• Vertigo (spinning sensation, loss of balance)
• Low sugar (glucose) levels in your blood (hypoglycaemia) (increased sweating, weakness, hunger, dizziness, trembling, headache, flushing or paleness, numbness, having a fast, pounding heartbeat)

Less frequent side effects

• Anaemia (tiredness, headaches, being short of breath when exercising, dizziness and looking pale)
• Low sodium levels in your blood characterised by nausea, vomiting, headache, confusion, fatigue, drowsiness, restlessness or irritability, muscle weakness, spasms or cramps, seizures and coma (hyponatraemia)
• Trouble sleeping (insomnia)
• Sleepiness
• Sleep disorders
• Migraine (severe headache)
• Low blood pressure characterised by dizziness and light-headedness
• Dizziness on standing up, especially when getting up from a sitting or lying position (orthostatic hypotension)
• Dry cough
• Blocked nose
• Sore throat and discomfort when swallowing (pharyngitis)
• Sinus disorder
• Diarrhoea
• Indigestion
• Nausea
• Pain of your stomach area
• Raised liver enzyme values when blood tests are done
• Hives (urticaria)
• A rare skin condition characterised by lesions or lumps under the skin (atypical cutaneous lymphoid infiltrates)
• Back pain, muscle cramps, leg pain, aching muscles, muscle tenderness or weakness, not caused by exercise (myalgia)
• Unusual tiredness or weakness
• Reported frequently only in type 2 diabetic patients with high blood pressure and protein in their urine. Side effects which may occur, but the frequency is unknown:
• Feeling depressed
• Altered perception or complete loss of taste
• Tinnitus (buzzing, hissing, whistling, ringing or other persistent noise in your ears
• Increased sensitivity of the skin to sun (photosensitivity)
• Joint pain (arthralgia)
• Erectile dysfunction/impotence (inability to get or maintain an erection)
• Generally feeling unwell (malaise)

Serious side effects and warning signs

This leaflet does not set out a separate list of serious side effects. The general warning signs below apply to any medicine.

General warning signs that apply to any medicine

How long can side effects last?

How long a side effect lasts depends on the effect, the product, how long it has been used, and the person. Some effects ease within days as the body adjusts. Others continue for as long as the product is used. A few can persist after stopping, and some need review rather than waiting.

• Settling effects — mild effects that ease over the first days or weeks of use
• Ongoing effects — effects that continue while the product is being used and improve after stopping
• Persistent effects — effects that continue after stopping and need medical review
• Delayed effects — effects that appear after weeks or months rather than immediately

Which of these applies to a particular effect is a clinical question. If a side effect is not settling, is getting worse, or is affecting your daily life, that is worth a conversation with a pharmacist or doctor regardless of how long it has been going on.

Factors that may affect side effects

The approved leaflet identifies the following cautions and factors.

Do not use it at all if

• If you are hypersensitive (allergic) to losartan potassium or any of the other ingredients of LOSARTAN BIOTECH 50 (listed in section 6)
• If you are pregnant or breastfeeding
• If you have a history of angioedema (severe reaction causing swelling of the face, lips, mouth, tongue or throat with or without difficulty in swallowing or breathing) relating to previous therapy with an angiotensin-converting enzyme (ACE) inhibitor or an angiotensin receptor blocker, such as LOSARTAN BIOTECH 50, or if you suffer from hereditary/idiopathic angioedema
• If you have a heart disorder affecting your heart muscle, known as hypertrophic obstructive cardiomyopathy
• If you have severe kidney disease
• If you have liver disease
• If you have a heart disorder affecting your heart valves, known as aortic stenosis
• If you have narrowing of the blood vessels to both, or to a single kidney
• If you are taking diuretics (medicines that increase the amount of water that you eliminate through your kidneys (water pills), such as spironolactone, triamterene and amiloride) that cause your body to retain potassium
• If you have a condition called porphyria (a rare hereditary disease in which there is abnormal metabolism of the blood pigment haemoglobin)
• Simultaneous administration of LOSARTAN BIOTECH 50 with lithium may lead to toxic blood concentrations of lithium
• If you are taking blood pressure-lowering medicine containing aliskiren. The safety of LOSARTAN BIOTECH 50 has not been established in children

Use with care, and tell your doctor, if

• You should tell your doctor or pharmacist about any medical problems you have or have had and about any allergies
• If you have recently suffered from excessive vomiting or diarrhoea
• If you are taking diuretics (water pills) or are under dietary salt restrictions leading to an extreme loss of fluid and salt in your body
• If you have liver or kidney disease
• If you suffer from porphyria
• If you have received a kidney transplant
• If you suffer from primary hyperaldosteronism (a syndrome associated with increased secretion of the hormone aldosterone)
• If you suffer from coronary heart disease or if you have had a stroke
• If you suffer from heart failure. Special caution is necessary when you are taking a beta- blocker (used to treat an abnormal heartbeat). Your doctor may check your kidney function, blood pressure and the amount of electrolytes (such as potassium) in your blood at regular intervals. Children and adolescents There is no experience with the use of LOSARTAN BIOTECH 50 in children. Therefore, LOSARTAN BIOTECH 50 should not be given to children

Pregnancy and breastfeeding

• You should not take LOSARTAN BIOTECH 50 if you are pregnant, breastfeeding or planning to become pregnant as safety in pregnancy and breastfeeding has not been established
• You should use adequate contraception while taking LOSARTAN BIOTECH 50
• If you are pregnant or breastfeeding, think you may be pregnant or are planning to have a baby, please consult your doctor, pharmacist or other health care provider for advice before taking LOSARTAN BIOTECH 50

Interactions and medicines to check

The approved leaflet names these interactions.

• Potassium-sparing diuretics (water pills), such as amiloride, triamterene and spironolactone
• Heparin, used to prevent blood clotting
• Trimethoprim-containing medicines, used to treat bacterial infections
• Medicines and supplements containing potassium
• Salt substitutes containing potassium
• ACE inhibitors (e.g. enalapril, lisinopril, ramipril) or aliskiren, used to treat high blood pressure
• Other medicines used to lower your blood pressure as they may cause a further reduction in your blood pressure
• Tricyclic antidepressants, used to treat depression
• Antipsychotics, used to treat psychotic disorders
• Baclofen, used to treat muscle spasms
• Amifostine, used to reduce the undesired side effects of certain cancer medicines
• Fluconazole, used to treat fungal infections
• Rifampicin, used to treat tuberculosis (TB)
• Lithium, used to treat depression or other mood disorders
• Nonsteroidal anti-inflammatory drugs (NSAIDs), such as indometacin, including cyclooxygenase-2 (COX-2) inhibitors and acetylsalicylic acid (aspirin), used to treat pain and inflammation. LOSARTAN BIOTECH 50 with food and drink

What to do if you experience side effects

If you think you are having a side effect, the response depends on how severe it is. Use the warning signs above first — if any of those apply, treat it as urgent.

If the symptom is severe or frightening

Get medical help immediately. Call 10177 for an ambulance, or 112 from a mobile phone, or go to the nearest emergency department. Take the product and its packaging with you if you can.

If the symptom is mild but bothering you

• Write down what the symptom is, when it started, and how it relates to when you take the product
• Check the leaflet that came with the product to see whether the symptom is listed
• Speak to your pharmacist — for many questions this is the fastest route to a useful answer
• Contact the prescriber if the symptom is affecting your daily life or is not settling

You can also report a suspected side effect in South Africa. Reporting does not replace getting medical advice, and you do not need to be certain the product was the cause.

When to seek urgent medical help

Some symptoms need medical attention straight away rather than an appointment in a few days. Do not wait to see whether they settle.

Get same-day medical advice if you have

• A high fever, or a rash together with feeling generally unwell
• Yellowing of the eyes or skin, or unusually dark urine
• Unusual bruising or bleeding that you cannot explain
• Severe or persistent vomiting or diarrhoea, especially if you cannot keep fluids down
• A sudden change in mood, or thoughts of harming yourself
• Any symptom that is rapidly getting worse

How to report a suspected side effect in South Africa

South Africa has an official system for reporting suspected side effects, run by the South African Health Products Regulatory Authority (SAHPRA). Reports from the public and from healthcare professionals are how safety signals get detected after a product is already in use.

Who can report

Anyone can report — you do not have to be a healthcare professional, and you do not need to prove that the product caused the problem. A suspicion is enough. Patients, caregivers and family members can all submit a report.

What to have ready

• The name of the product, its strength and form, and the batch number if you have it
• Why it was being used, and when it was started and stopped
• What the suspected reaction was, when it began, and how long it lasted
• Any other medicines, supplements or remedies being used at the same time
• Basic details about the person affected — age and sex are usually enough

How to report

SAHPRA accepts adverse reaction reports through its e-Services reporting system and through the Med Safety mobile app. Healthcare professionals can also report through the same routes. Current forms and access points are published on the SAHPRA site.

• SAHPRA Health Products Vigilance — the main vigilance and reporting hub
• SAHPRA e-Services — current adverse reaction reporting access

For a fuller walkthrough see how to report an adverse drug reaction.

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