Based on NIH | Can Losartan cause anxiety, and what should I do if I start feeling anxious while taking it?

Losartan and anxiety: what to know
Losartan (an angiotensin II receptor blocker used for high blood pressure and heart/kidney protection) can be associated with anxiety in some users, although this appears to be uncommon. ^[1] Anxiety, nervousness, sleep problems like insomnia, and related neuro‑psychiatric symptoms are listed among post‑marketing adverse reactions for losartan and for the losartan/hydrochlorothiazide combination. ^{[1] [2]} Large clinical trials have generally shown losartan to be well‑tolerated with side effects similar to placebo, suggesting that when anxiety occurs it is relatively infrequent. ^{[3] [4]}

How often does anxiety occur?

• In controlled trials, the most common side effect reported more than placebo was dizziness; anxiety was not among the most frequent events, indicating it likely occurs at a low rate. ^{[3] [4]}
• Nevertheless, official product information includes anxiety, panic disorder, nervousness, sleep disorder/insomnia, and depression as possible adverse effects. ^{[5] [1]}
• Combination tablets with hydrochlorothiazide (HCTZ) also list anxiety and insomnia, which means some users may notice symptoms after starting or changing dose, especially with the combo product. ^{[2] [6]}

Why might this happen?

• The exact reason is not clear; losartan works on the renin‑angiotensin system, which is active in the brain as well as the body. ^[7]
• Experimental studies in animals actually suggest AT1‑receptor blockers like losartan may reduce anxiety‑like behavior, so in people who feel anxious on losartan, it may reflect individual sensitivity, drug interactions, sleep disruption, dehydration/electrolyte changes (especially if taking HCTZ), or unrelated anxiety that coincidentally starts after therapy. ^{[8] [9]}

What to do if you feel anxious on losartan

• Track timing: note when the anxiety started, how long it lasts, and any link to dosing, missed meals, caffeine, alcohol, or new medications. A clear temporal link to starting or increasing losartan (or adding HCTZ) raises suspicion of a drug effect. ^{[2] [5]}
• Check for other side effects: dizziness, palpitations, sleep trouble, or mood changes can cluster with anxiety and help your clinician assess causality. ^{[1] [5]}
• Review other causes: dehydration and low sodium or potassium from diuretics can worsen anxiety and restlessness; a clinician may check blood pressure, heart rate, and basic labs. ^[10]
• Do not stop abruptly without guidance: blood pressure can rise if you stop suddenly; instead, contact your prescriber promptly to discuss options. ^[4]

Options your clinician may consider

• Dose timing or adjustment: shifting dosing away from bedtime can help if insomnia/restlessness predominates; in some situations a temporary dose reduction may be considered while monitoring blood pressure. ^[11]
• Switch within the class: many people who do not tolerate one medication may do well on another ARB (e.g., valsartan, irbesartan) with similar benefits. This is a common, reasonable strategy if anxiety seems medication‑related. ^[4]
• Change class: if anxiety persists, an alternative such as a calcium‑channel blocker or thiazide alone may be considered based on your conditions and tolerability. ^[4]
• Address sleep and stress: short‑term sleep hygiene measures (consistent schedule, limiting caffeine/alcohol, and device use before bed) and relaxation techniques may ease symptoms while you and your clinician decide on medication changes. ^{[2] [5]}

When to seek urgent care

• Seek immediate help for severe anxiety with chest pain, shortness of breath, fainting, thoughts of self‑harm, or an allergic reaction (hives, swelling, trouble breathing). These symptoms need urgent assessment regardless of cause. ^[1]

Quick comparison: reported neuro‑psychiatric symptoms

Product	Reported neuro‑psychiatric effects (examples)
Losartan tablet (brand/generic)	Anxiety, panic disorder, nervousness, sleep disorder/insomnia, depression, memory impairment, tremor, vertigo. [1] [5]
Losartan/HCTZ (combination)	Anxiety, anxiety disorder, nervousness, insomnia, sleep disorder, depression, tremor, vertigo. [2] [6]

Bottom line

• Anxiety can occur with losartan or losartan/HCTZ, but it appears to be uncommon; overall tolerability in trials is similar to placebo. ^{[3] [4]}
• If you notice new or worsening anxiety after starting or changing losartan, it may be related, especially if accompanied by sleep problems or nervousness, and you should discuss dose timing, possible dose adjustment, or switching medications with your prescriber. ^{[1] [2]}

If you’d like, I can help you think through your current dose, when symptoms started, and other medications to prepare for a productive conversation with your clinician.