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. The adverse reaction information from clinical trials does, however, provide a basis for identifying the adverse events that appear to be related to drug use and for approximating rates.
Irbesartan-Hydrochlorothiazide
Irbesartan and hydrochlorothiazide tablets have been evaluated for safety in 1694 patients treated for essential hypertension in 6 clinical trials. In Studies I through IV with irbesartan and hydrochlorothiazide tablets, no adverse events peculiar to this combination drug product have been observed. Adverse events have been limited to those that were reported previously with irbesartan or hydrochlorothiazide (HCTZ). The overall incidence of adverse events was similar with the combination and placebo. In general, treatment with irbesartan and hydrochlorothiazide tablets was well tolerated. For the most part, adverse events have been mild and transient in nature and have not required discontinuation of therapy. In controlled clinical trials, discontinuation of irbesartan and hydrochlorothiazide therapy due to clinical adverse events was required in only 3.6%. This incidence was significantly less (p=0.023) than the 6.8% of patients treated with placebo who discontinued therapy.
In these double-blind controlled clinical trials, the following adverse events reported with irbesartan and hydrochlorothiazide tablets occurred in ≥1% of patients, and more often on the irbesartan-hydrochlorothiazide combination than on placebo, regardless of drug relationship:
| Irbesartan/ HCTZ (n=898) (%) | Placebo (n=236) (%) | Irbesartan (n=400) (%) | HCTZ (n=380) (%) |
Body as a Whole | | | | |
Chest Pain | 2 | 1 | 2 | 2 |
Fatigue | 6 | 3 | 4 | 3 |
Influenza | 3 | 1 | 2 | 2 |
Cardiovascular | | | | |
Edema | 3 | 3 | 2 | 2 |
Tachycardia | 1 | 0 | 1 | 1 |
Gastrointestinal | | | | |
Abdominal Pain | 2 | 1 | 2 | 2 |
Dyspepsia/heartburn | 2 | 1 | 0 | 2 |
Nausea/vomiting | 3 | 0 | 2 | 2 |
Immunology | | | | |
Allergy | 1 | 0 | 1 | 1 |
Musculoskeletal | | | | |
Musculoskeletal Pain | 6 | 5 | 6 | 10 |
Nervous System | | | | |
Dizziness | 8 | 4 | 6 | 5 |
Dizziness Orthostatic | 1 | 0 | 1 | 1 |
Renal/Genitourinary | | | | |
Abnormality Urination | 2 | 1 | 1 | 2 |
The following adverse events were also reported at a rate of 1% or greater, but were as, or more, common in the placebo group: headache, sinus abnormality, cough, URI, pharyngitis, diarrhea, rhinitis, urinary tract infection, rash, anxiety/nervousness, and muscle cramp.
Adverse events occurred at about the same rates in men and women, older and younger patients, and black and non-black patients.
Adverse events in Studies V and VI were similar to those described above in Studies I through IV.
Irbesartan
Other adverse events that have been reported with irbesartan, without regard to causality, are listed below:
Body as a Whole: fever, chills, orthostatic effects, facial edema, upper extremity edema
Cardiovascular: flushing, hypertension, cardiac murmur, myocardial infarction, angina pectoris, hypotension, syncope, arrhythmic/conduction disorder, cardiorespiratory arrest, heart failure, hypertensive crisis
Dermatologic: pruritus, dermatitis, ecchymosis, erythema face, urticaria
Endocrine/Metabolic/Electrolyte Imbalances: sexual dysfunction, libido change, gout
Gastrointestinal: diarrhea, constipation, gastroenteritis, flatulence, abdominal distention
Musculoskeletal/Connective Tissue: musculoskeletal trauma, extremity swelling, muscle cramp, arthritis, muscle ache, musculoskeletal chest pain, joint stiffness, bursitis, muscle weakness
Nervous System: anxiety/nervousness, sleep disturbance, numbness, somnolence, vertigo, emotional disturbance, depression, paresthesia, tremor, transient ischemic attack, cerebrovascular accident
Renal/Genitourinary: prostate disorder
Respiratory: cough, upper respiratory infection, epistaxis, tracheobronchitis, congestion, pulmonary congestion, dyspnea, wheezing
Special Senses: vision disturbance, hearing abnormality, ear infection, ear pain, conjunctivitis
Hydrochlorothiazide
Other adverse events that have been reported with hydrochlorothiazide, without regard to causality, are listed below:
Body as a Whole: weakness
Digestive: pancreatitis, jaundice (intrahepatic cholestatic jaundice), sialadenitis, cramping, gastric irritation
Hematologic: aplastic anemia, agranulocytosis, leukopenia, hemolytic anemia, thrombocytopenia
Hypersensitivity: purpura, photosensitivity, urticaria, necrotizing angiitis (vasculitis and cutaneous vasculitis), fever, respiratory distress including pneumonitis and pulmonary edema, anaphylactic reactions
Metabolic: hyperglycemia, glycosuria, hyperuricemia
Musculoskeletal: muscle spasm
Nervous System/Psychiatric: restlessness
Renal: renal failure, renal dysfunction, interstitial nephritis
Skin: erythema multiforme including Stevens-Johnson syndrome, exfoliative dermatitis including toxic epidermal necrolysis
Special Senses: transient blurred vision, xanthopsia
Initial Therapy
In the moderate hypertension Study V (mean SeDBP between 90 and 110 mmHg), the types and incidences of adverse events reported for patients treated with irbesartan and hydrochlorothiazide tablets were similar to the adverse event profile in patients on initial irbesartan or HCTZ monotherapy. There were no reported events of syncope in the irbesartan and hydrochlorothiazide tablets treatment group and there was one reported event in the HCTZ treatment group. The incidences of pre-specified adverse events on irbesartan and hydrochlorothiazide tablets, irbesartan, and HCTZ, respectively, were: 0.9%, 0%, and 0% for hypotension; 3.0%, 3.8%, and 1.0% for dizziness; 5.5%, 3.8%, and 4.8% for headache; 1.2%, 0%, and 1.0% for hyperkalemia; and 0.9%, 0%, and 0% for hypokalemia. The rates of discontinuation due to adverse events on irbesartan and hydrochlorothiazide tablets, irbesartan alone, and HCTZ alone were 6.7%, 3.8%, and 4.8%.
In the severe hypertension (SeDBP ≥110 mmHg) Study VI, the overall pattern of adverse events reported through 7 weeks of follow-up was similar in patients treated with irbesartan and hydrochlorothiazide tablets as initial therapy and in patients treated with irbesartan as initial therapy. The incidences of the pre-specified adverse events on irbesartan and hydrochlorothiazide tablets and irbesartan, respectively, were: 0% and 0% for syncope; 0.6% and 0% for hypotension; 3.6% and 4.0% for dizziness; 4.3% and 6.6% for headache; 0.2% and 0% for hyperkalemia; and 0.6% and 0.4% for hypokalemia. The rates of discontinuation due to adverse events were 2.1% and 2.2%. [See Clinical Studies (14.2).]