Mibefradil Side Effects

Applies to mibefradil: oral tablet.

General adverse events

The following ADEs were more common among patients treated with mibefradil compared with placebo in controlled trials (incidence of ADE associated with mibefradil 100 mg/day vs. placebo): headache (8% vs. 6%), leg edema (4% vs. 3%), rhinitis (3% vs. 0%), abdominal pain (2% vs. 1%), lightheadedness (3% vs. 0%), dyspepsia (2% vs. 1%).^[Ref]

In general, data from safety evaluations in 3,430 patients with hypertension or chronic stable angina pectoris, show that mibefradil was well tolerated. Most adverse drug events (ADEs) were mild to moderate and transient. In placebo-controlled trials the rate of discontinuation of therapy due to ADEs was similar to that of placebo except for dizziness, which was more common among patients treated with mibefradil.^[Ref]

Nervous system

Two side effects of the nervous system have more often been associated with the use of mibefradil compared with placebo: headache (8% vs 6%) and lightheadedness (3% vs. 0%). Dizziness has often been reported as one of the more common side effects, seen in approximately 7% of patients. In some controlled trials, the incidence of dizziness among treated patients exceeded that among patients who received placebo.^[Ref]

The following nervous system side effects have been associated with the use of 100 mg of mibefradil, but occured at a frequency equal to or less than placebo: dizziness, and fatigue. Dizziness occurred in a dose-related manner in placebo-controlled trials over a daily dose range of 50 to 100 mg. Whether related to mibefradil therapy or not, the following have occurred in at least 0.5% of patients in controlled trials: increased sweating, generalized weakness, parestheias, and ear buzzing.^[Ref]

Cardiovascular

The only cardiovascular side effect that has occurred more often among treated patients compared with placebo is leg edema (4% vs. 3%). Leg edema has been dose-related. When ECG testing was performed, the main events observed among patients treated with mibefradil were first-degree AV block (8%, maximal PQ interval 240 msec), sinus bradycardia (5%), and short Wenckebach episodes during sleep (5%). All ECG events were dose-related. (Patients were treated with up to 150 mg/day.) As a selective T-channel calcium ion influx antagonist, mibefradil has not been associated with negative effects on left ventricular cardiac contractility at therapeutic doses and plasma levels.^[Ref]

The following cardiovascular side effects occurred in at least 1% of patients treated with daily doses of 100 mg, but occurred at a frequency equal to or less than placebo: angina pectoris, flushing, and palpitations. Flushing occurred in a dose-related manner in placebo-controlled trials over a daily dose range of 50 to 100 mg. Whether related to mibefradil or not, the following have occurred in at least 0.5% of patients in controlled trials: orthostatic complaints, postural hypotension, syncope, bradycardia, cardiac failure, nonspecific chest pain, angioedema, and hypotension. Flushing and orthostatic hypotension have been attributed to the peripheral vasodilatory properties of this drug.^[Ref]

Respiratory

Rhinitis is the only reported respiratory system side effect that occurred significantly more often among treated patients compared with placebo (3% vs. 0%).^[Ref]

Rarely, upper respiratory infection has been associated with the use of mibefradil (at least 1% of patients). A causal relationship has not been established, and the incidence of upper respiratory tract infection among patients treated with placebo was similar or greater in controlled studies. Bronchitis, coughing, dyspnea, nasal congestion, pharyngitis, and sinusitis have been associated with the use of mibefradil in approximately 0.5% of patients.^[Ref]

Gastrointestinal

Gastrointestinal side effects have basically been limited to abdominal pain in 2%, dyspepsia in 2%, and nausea or vomiting in 1% of patients. In general, the frequency of these side effects was similar among placebo-treated patients in controlled trials.^[Ref]

Whether related to mibefradil therapy or not, the following have occurred in at least 0.5% of patients in controlled trials: constipation, diarrhea, flatulence, gastroenteritis, and rectal hemorrhage.^[Ref]

Hypersensitivity

Hypersensitivity reactions to mibefradil have occurred in approximately 1% of patients treated with daily doses of 100 mg. (Similar "allergic reactions" or rashes were observed among placebo-treated patients at a similar frequency.) Angioedema has rarely been associated with the use of this drug.^[Ref]

Exfoliative dermatitis has been associated with the use of mibefradil in approximately 0.5% of patients.^[Ref]

Musculoskeletal

Musculoskeletal pains and cramps and arthritic pains have been associated with the use of mibefradil in approximately 0.5% of patients.^[Ref]

Psychiatric

Psychiatric complaints that have occurred in approximately 0.5% of treated patients include anxiety, depression, and insomnia.^[Ref]

Genitourinary

The only reported genitourinary side effect has been impotence in approximately 0.5% of male patients.^[Ref]

Dermatologic

Dermatologic side effects have been associated with hypersensitivity reactions, and include exfoliative dermatitis or rash in approximately 0.5% of patients.^[Ref]

Ocular

Conjunctivitis is the only reported ocular side effect. Its frequency approximates 0.5% and compares with similar complaints among placebo-treated patients in controlled trials.^[Ref]

See also:

Further information

Mibefradil side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

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