From the Guidelines
Diltiazem is not generally considered ototoxic. Unlike certain medications such as aminoglycoside antibiotics, loop diuretics, platinum-based chemotherapy agents, or high-dose aspirin, diltiazem has not been associated with damage to the inner ear structures or hearing loss. Diltiazem is a calcium channel blocker primarily used to treat hypertension, angina, and certain arrhythmias by relaxing blood vessels and reducing heart rate. Its mechanism of action involves blocking calcium channels in cardiac and vascular smooth muscle cells, not affecting the specialized structures of the inner ear. While diltiazem can cause various side effects including dizziness, headache, flushing, edema, and bradycardia, these are not related to direct ototoxicity. If a patient experiences dizziness while taking diltiazem, this is more likely due to its blood pressure-lowering effects rather than damage to the inner ear. Patients concerned about medication effects on hearing should discuss these concerns with their healthcare provider. The provided evidence 1 does not mention diltiazem as an ototoxic agent, and the most recent study 1 discusses ototoxicity in the context of other medications, further supporting the notion that diltiazem is not typically associated with ototoxicity. Therefore, based on the available evidence, diltiazem can be considered a safe option in terms of ototoxicity.
From the FDA Drug Label
The following postmarketing events have been reported infrequently in patients receiving diltiazem hydrochloride tablets: ... tinnitus
- Ototoxicity is related to ear or hearing damage, and tinnitus is a symptom of ototoxicity, which is characterized by ringing or other sounds in the ears.
- The presence of tinnitus in the list of postmarketing events suggests that diltiazem may be associated with ototoxic effects in some patients.
- However, it is essential to note that the relationship between diltiazem and ototoxicity is not definitively established, and the incidence of such events is infrequent 2.
From the Research
Diltiazem Ototoxicity
- There is no direct evidence in the provided studies that suggests diltiazem is ototoxic 3, 4, 5, 6.
- However, a study found that diltiazem can be used as an otoprotectant against cisplatin-induced ototoxicity in a mouse model, suggesting that it may have protective effects on the ear 7.
- The study used intratympanic diltiazem-chitosan hydrogel to protect against cisplatin-induced ototoxicity and found that it reduced auditory brainstem response threshold shifts and protected ribbon synapses in the apical turn of the cochlea 7.
- None of the studies provided a direct link between diltiazem use and ototoxicity, but rather explored its potential as an otoprotectant or discussed its pharmacological properties and therapeutic efficacy in other areas 3, 4, 5, 6.