Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
Hypertension
Losartan potassium has been evaluated for safety in more than 3300 adult patients treated for essential hypertension and 4058 patients/subjects overall. Over 1200 patients were treated for over 6 months and more than 800 for over one year.
Treatment with losartan potassium was well-tolerated with an overall incidence of adverse events similar to that of placebo. In controlled clinical trials, discontinuation of therapy for adverse events occurred in 2.3% of patients treated with losartan potassium and 3.7% of patients given placebo. In 4 clinical trials involving over 1000 patients on various doses (10 to 150 mg) of losartan potassium and over 300 patients given placebo, the adverse events that occurred in ≥2% of patients treated with losartan potassium and more commonly than placebo were: dizziness (3% vs. 2%), upper respiratory infection (8% vs. 7%), nasal congestion (2% vs. 1%), and back pain (2% vs. 1%).
The following less common adverse reactions have been reported:
Blood and lymphatic system disorders: Anemia.
Psychiatric disorders: Depression.
Nervous system disorders: Somnolence, headache, sleep disorders, paresthesia, migraine.
Ear and labyrinth disorders: Vertigo, tinnitus.
Cardiac disorders: Palpitations, syncope, atrial fibrillation, CVA.
Respiratory, thoracic and mediastinal disorders: Dyspnea.
Gastrointestinal disorders: Abdominal pain, constipation, nausea, vomiting.
Skin and subcutaneous tissue disorders: Urticaria, pruritus, rash, photosensitivity.
Musculoskeletal and connective tissue disorders: Myalgia, arthralgia.
Reproductive system and breast disorders: Impotence.
General disorders and administration site conditions: Edema.
Cough
Persistent dry cough (with an incidence of a few percent) has been associated with ACE-inhibitor use and in practice can be a cause of discontinuation of ACE-inhibitor therapy. Two prospective, parallel-group, double-blind, randomized, controlled trials were conducted to assess the effects of losartan on the incidence of cough in hypertensive patients who had experienced cough while receiving ACE-inhibitor therapy. Patients who had typical ACE-inhibitor cough when challenged with lisinopril, whose cough disappeared on placebo, were randomized to losartan 50 mg, lisinopril 20 mg, or either placebo (one study, n=97) or 25 mg hydrochlorothiazide (n=135). The double-blind treatment period lasted up to 8 weeks. The incidence of cough is shown in Table 1 below.
Table 1 | * Demographics = (89% Caucasian, 64% female) |
| † Demographics = (90% Caucasian, 51% female) |
Study 1*
| HCTZ
| Losartan
| Lisinopril
|
Cough
| 25%
| 17%
| 69%
|
Study 2†
| Placebo
| Losartan
| Lisinopril
|
Cough
| 35%
| 29%
| 62%
|
These studies demonstrate that the incidence of cough associated with losartan therapy, in a population that all had cough associated with ACE-inhibitor therapy, is similar to that associated with hydrochlorothiazide or placebo therapy.
Cases of cough, including positive re-challenges, have been reported with the use of losartan in postmarketing experience.
Hypertensive Patients with Left Ventricular Hypertrophy
In the losartan Intervention for Endpoint (LIFE) study, adverse reactions with losartan potassium were similar to those reported previously for patients with hypertension.
Nephropathy in Type 2 Diabetic Patients
In the Reduction of Endpoints in NIDDM with the Angiotensin II Receptor Antagonist Losartan (RENAAL) study involving 1513 patients treated with losartan potassium or placebo, the overall incidences of reported adverse events were similar for the two groups. Discontinuations of losartan potassium because of side effects were similar to placebo (19% for losartan potassium, 24% for placebo). The adverse events, regardless of drug relationship, reported with an incidence of ≥4% of patients treated with losartan potassium and occurring with ≥2% difference in the losartan group vs. placebo on a background of conventional antihypertensive therapy, were asthenia/fatigue, chest pain, hypotension, orthostatic hypotension, diarrhea, anemia, hyperkalemia, hypoglycemia, back pain, muscular weakness, and urinary tract infection.