Calcium channel blocker toxicity is the taking of too much of the medications known as calcium channel blockers (CCBs) either by accident or on purpose. This often causes a slow heart rate and low blood pressure. This can progress to the heart stopping altogether. Some CCBs can also cause a fast heart rate as a result of the low blood pressure. Other symptoms may include nausea, vomiting, sleepiness, and shortness of breath. Symptoms usually occur in the first six hours but with some forms of the medication may not start until 24 after hours.

do calcium channel blockers cause shortness of breath?
yes