Side effects to losartan potassium
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Side Effects of Losartan Potassium
Losartan potassium, a selective angiotensin II receptor antagonist, is widely used for the treatment of hypertension. While it is generally well-tolerated, several side effects have been documented in clinical trials and post-marketing surveillance.
Common Side Effects: Headache, Dizziness, and Fatigue
The most frequently reported side effects of losartan potassium include headache, dizziness, and fatigue. In clinical trials involving approximately 2,900 hypertensive patients, headache and dizziness were reported by 14.1% of patients, while fatigue was reported by 3.8% of patients1 2. These side effects were also commonly observed in patients receiving a placebo, indicating that they may not be solely attributable to losartan.
Respiratory Issues: Upper Respiratory Infections and Cough
Upper respiratory infections and cough are also noted among the side effects. Upper respiratory infections were reported by 6.5% of patients, and cough by 3.1%1 2. Interestingly, the incidence of cough with losartan is significantly lower compared to angiotensin-converting enzyme (ACE) inhibitors, which have a higher association with this side effect (8.8%)1 2.
Rare but Serious Side Effects: Hyperkalemia and Angioedema
Hyperkalemia, or elevated potassium levels in the blood, is a notable concern, especially when losartan is used in combination with potassium-sparing diuretics like spironolactone or triamterene3. In the RENAAL study, 38.4% of patients treated with losartan had serum potassium levels of ≥5.0 mmol/L, which was associated with an increased risk of renal events10. Angioedema and acute hepatitis have also been reported, albeit rarely, in patients treated with losartan3.
Other Considerations: Hypotension and Withdrawal Effects
First-dose hypotension is uncommon with losartan, and withdrawal effects such as rebound hypertension have not been observed in clinical trials1 2. The overall rate of patient withdrawal due to adverse experiences with losartan is lower than that of placebo (2.3% vs. 3.7%)1 2 4.
Special Populations: Pregnancy and Renal Impairment
Losartan should not be administered to pregnant women and breastfeeding mothers due to potential risks to fetal growth and newborn health3. Caution is also advised when prescribing losartan to patients with renal failure or liver dysfunction, as these conditions can affect the drug's metabolism and excretion3 9.
Conclusion
Losartan potassium is generally well-tolerated, with common side effects including headache, dizziness, and fatigue. While it has a lower incidence of cough compared to ACE inhibitors, it can cause hyperkalemia, particularly when used with potassium-sparing diuretics. Rare but serious side effects like angioedema and acute hepatitis have been reported. Overall, losartan's safety profile makes it a viable option for many patients with hypertension, but careful monitoring is essential, especially in those with renal impairment or other complicating conditions.
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Most relevant research papers on this topic
Safety and tolerability of losartan potassium, an angiotensin II receptor antagonist, compared with hydrochlorothiazide, atenolol, felodipine ER, and angiotensin-converting enzyme inhibitors for the treatment of systemic hypertension.
Losartan potassium is an effective and well-tolerated treatment for systemic hypertension, with a better tolerability profile than other antihypertensive agents.
Highly CitedSafety and tolerability of losartan compared with atenolol, felodipine and angiotensin converting enzyme inhibitors
Losartan has demonstrated an excellent tolerability profile in controlled clinical trials compared to other antihypertensive agents, with no significant differences observed for demographic subgroups.
RCT
Large Human Trial[Drug-interactions and adverse effects of losartan potassium, an angiotensin II receptor antagonist].
Losartan potassium has few side effects, but caution is needed when using it with potassium-sparing diuretics, and in pregnant or breastfeeding women, and those with renal or liver dysfunction.
Efficacy and safety of losartan.
Losartan is an effective and well-tolerated antihypertensive agent, with a smooth antihypertensive profile and similar effects to other drugs, with dizziness being the most common adverse experience.
RCTLarge Human TrialLosartan Potassium
Losartan potassium is a promising new antihypertensive agent with a novel mechanism of action, good efficacy, and favourable tolerability profile.
Antihypertensive efficacy and tolerability of once daily losartan potassium compared with captopril in patients with mild to moderate essential hypertension
Once-daily losartan potassium is more effective in lowering sitting diastolic blood pressure than captopril in patients with mild to moderate essential hypertension, with both drugs well-tolerated.
RCTAntihypertensive and anti-albuminuric effects of losartan potassium and felodipine in Chinese elderly hypertensive patients with or without non-insulin-dependent diabetes mellitus.
Losartan potassium treatment reduces albuminuria more effectively than felodipine in Chinese elderly hypertensive patients with or without non-insulin-dependent diabetes mellitus.
RCTEffects of losartan on a background of hydrochlorothiazide in patients with hypertension.
Losartan combined with hydrochlorothiazide effectively reduces blood pressure in hypertensive patients, with a dose-response relationship observed in this patient population.
RCTLarge Human TrialHighly CitedA Risk-Benefit Assessment of Losartan Potassium in the Treatment of Hypertension
Losartan potassium is an effective once-daily antihypertensive drug with well-tolerated dizziness, but long-term tolerability and effects beyond blood pressure control require further investigation.
Increased serum potassium affects renal outcomes: a post hoc analysis of the Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan (RENAAL) trial
Losartan treatment is associated with a high risk of increased serum potassium levels, which in turn increases the risk of renal outcomes in patients with diabetes and nephropathy.
RCTLarge Human Trial
Rigorous JournalHighly Cited