Serious adverse reactions have been rare in studies carried out to date, but it should be recognized that patients with impaired ventricular function and cardiac conduction abnormalities have usually been excluded from these studies.
The adverse events described below represent events observed in clinical studies of hypertensive patients receiving either diltiazem hydrochloride tablets or diltiazem hydrochloride extended-release capsules, as well as experiences observed in studies of angina and during marketing. The most common events in hypertension studies are shown in a table with rates in placebo patients shown for comparison. Less common events are listed by body system; these include any adverse reactions seen in angina studies that were not observed in hypertension studies. In all hypertensive patients studied (over 900), the most common adverse events were edema (9%), headache (8%), dizziness (6%), asthenia (5%), sinus bradycardia (3%), flushing (3%), and first-degree AV block (3%). Only edema and perhaps bradycardia and dizziness were dose related. The most common events observed in clinical studies (over 2,100 patients) of angina patients and hypertensive patients receiving diltiazem hydrochloride tablets or diltiazem hydrochloride extended-release capsules were (i.e., greater than 1%) edema (5.4%), headache (4.5%), dizziness (3.4%), asthenia (2.8%), first-degree AV block (1.8%), flushing (1.7%), nausea (1.6%), bradycardia (1.5%), and rash (1.5%).
Double Blind Placebo Controlled Hypertension TrialsAdverse | Diltiazem N = 315 No. pts (%) | Placebo N = 211 No. pts (%) |
Headache | 38 (12%) | 17 (8%) |
AV block first degree | 24 (7.6%) | 4 (1.9%) |
Dizziness | 22 (7%) | 6 (2.8%) |
Edema | 19 (6%) | 2 (0.9%) |
Bradycardia | 19 (6%) | 3 (1.4%) |
ECG abnormality | 13 (4.1%) | 3 (1.4%) |
Asthenia | 10 (3.2%) | 1 (0.5%) |
Constipation | 5 (1.6%) | 2 (0.9%) |
Dyspepsia | 4 (1.3%) | 1 (0.5%) |
Nausea | 4 (1.3%) | 2 (0.9%) |
Palpitations | 4 (1.3%) | 2 (0.9%) |
Polyuria | 4 (1.3%) | 2 (0.9%) |
Somnolence | 4 (1.3%) | — |
Alk phos increase | 3 (1%) | 1 (0.5%) |
Hypotension | 3 (1%) | 1 (0.5%) |
Insomnia | 3 (1%) | 1 (0.5%) |
Rash | 3 (1%) | 1 (0.5%) |
AV block second degree | 2 (0.6%) | — |
In addition, the following events were reported infrequently (less than 1%) with diltiazem hydrochloride extended-release capsules or diltiazem hydrochloride tablets or have been observed in angina or hypertension trials.
Cardiovascular: Angina, arrhythmia, second- or third-degree AV block (see
Conduction Warning), bundle branch block, congestive heart failure, syncope, tachycardia, ventricular extrasystoles.
Nervous System: Abnormal dreams, amnesia, depression, gait abnormality, hallucinations, nervousness, paresthesia, personality change, tremor.
Gastrointestinal: Anorexia, diarrhea, dry mouth, dysgeusia, mild elevations of SGOT, SGPT, and LDH (see
Hepatic Warnings), thirst, vomiting, weight increase.
Dermatological: Petechiae, photosensitivity, pruritus, urticaria.
Other: Amblyopia, CPK increase, dyspnea, epistaxis, eye irritation, hyperglycemia, hyperuricemia, impotence, muscle cramps, nasal congestion, nocturia, osteoarticular pain, sexual difficulties, tinnitus.
The following post-marketing events have been reported infrequently in patients receiving diltiazem hydrochloride: acute generalized exanthematous pustulosis, allergic reactions, alopecia, angioedema (including facial or periorbital edema), asystole, erythema multiforme (including Stevens-Johnson Syndrome, toxic epidermal necrolysis), extrapyramidal symptoms, gingival hyperplasia, hemolytic anemia, increased bleeding time, leukopenia, photosensitivity (including lichenoid keratosis and hyperpigmentation at sun-exposed skin areas), purpura, retinopathy, myopathy, and thrombocytopenia. There have been observed cases of a generalized rash, some characterized as leukocytoclastic vasculitis. In addition, events such as myocardial infarction have been observed which are not readily distinguishable from the natural history of the disease in these patients. A definitive cause and effect relationship between these events and diltiazem hydrochloride therapy cannot yet be established. Exfoliative dermatitis (proven by rechallenge) has also been reported.