Losartan Potassium
Losartan potassium is an Angiotensin II receptor blocker, mainly used to control Hypertension, protects kidney function in type 2 diabetic patients and reduces the risk of stroke. It was introduced in the 1986s & gained approval for medical use in 1995. It is one of the most commonly prescribed Antihypertensive medicine in the world.
Mechanism of action;
losartan functions by selectively inhibiting the binding of Angiotensin ll to receptors. Angiotensin ll is a hormone that causes vasoconstriction by release of aldosterone. This inhibition relaxes blood vessals (vasodilation), increase blood flow & oxygen supply to heart. Blocking of Angiotensin receptor also increase the excretion of sodium & water from kidneys that lowers the risk of heart attack, stroke, and kidney damage.
It is a specific inhibitor of the urate transporter 1, prevents the uptake of uric acid into cells , leaving more uric acid in the bloodstream available to be excreted by the kidneys.
Indications
Hypertension
Left Ventricular Hypertrophy
Uricosuric
Prevents kidney damage in type ll diabetes & nephropathy
To lower the risk of stroke
DOSE
It is available in 25 mg , 50mg & 100mg oral tablets. Dose varies depending on the condition being treated.
For Hypertension
Initial dose: 50 mg once a day
Maximum dose: 100 mg once a day
Heart Failure: as per ACC/AHA 2022 guidelines 25 to 50 mg initial dose with a target dose between 50 to 150 mg per day.
Diabetic Nephropathy: Starting with 50 mg dayily can be raised to 100 mg based on patient condition.
For children above 6 Years of age
Starting dose: 0.7 mg/kg once a day , maximum 50mg per day.
Precautions
Pregnancy: In 2014 FDA declared losartan unsafe in pregnancy as it can cause fetal injury or death.
Hyperkalemia: studies show that there is risk of high potassium levels or electrolyte imbalance with the use of losartan. Avoid to take potassium supplements consult your health professional.
Patients with Kidney or Liver Disease – Needs dose adjustment & monitoring.
Over-the-counter medicines; If you are taking any over-the-counter (OTC) medicines, vitamins or supplements need to consult healthcare provider.
Drug interactios; It has adverse drug interactios with other drugs like Rifampicin, Phenobarbitol & anti fungal (Fluconazole) possibly effecting its anti hypertensive activity.
Side effects/ Adverse effects
common side effects
Respiratoy infections
Dizziness
Anemia
Back pain
Diarrhoea
serious side effects
Kidney Damage; can be seen if swelling at legs or foot, less urination, feeling tiredness, shortness of breathe, nausea, seizuires
Hyperkalemia; Electrolyte imbalances especially elevated Potassium levels may occur in patient that can be fatal. some symptoms include fatigue, bradycardia or feeling of skipped heartbeat and abnormal heart rhythm.
Severe Allergic reaction; Allergic reaction, chest pain, diarrhoea, hypoglycemia, swelling of the face, lips, mouth, tongue, or throat may be seen in patients with type ll diabetes & kidney damage.
Important Guidelines for Taking Losartan
With or Without Food – it can be taken with or withoutfood but need to take it at the same time daily
With Water – The best option is to take with one glass of plain water.
Avoid Grapefruit Juice – It can interfere with metabolism and affect drug levels. Avoid Potassium-Rich Juices (like Orange Juice) – Losartan can raise K levels & extra use of potassium may lead to hyperkalemia.
Recent Research
Recent studies have explored losartan’s potential beyond its established uses:
COVID-19: Investigations are ongoing into losartan’s efficacy in mitigating severe respiratory complications associated with COVID-19, given its effects on the renin-angiotensin system.
Marfan Syndrome: Research suggests losartan may reduce aortic dilation in patients with Marfan syndrome, potentially decreasing the need for surgical intervention.
Alzheimer’s Disease: Preliminary studies indicate that losartan could have neuroprotective effects, possibly slowing the progression of Alzheimer’s disease.
These emerging areas of research highlight the versatility of losartan and its potential applications beyond traditional cardiovascular and renal indications.